Materials

23 pages, 7092 KB

Open AccessEditor’s ChoiceReview

Toward High-Performance Mg-Matrix Composites: Recent Advances in Ceramic Reinforcement Strategies and Processing Innovations

by Yuefeng Ying, Weideng Wang, Guoqiang You, Yan Yang, Bin Jiang, Lin Yue and Qilin Shao

Materials 2026, 19(2), 365; https://doi.org/10.3390/ma19020365 - 16 Jan 2026

Cited by 4 | Viewed by 1499

Abstract

Magnesium matrix composites formed by incorporating ceramic particles into a magnesium alloy matrix can effectively leverage the complementary properties of the matrix and reinforcement. This approach significantly enhances the mechanical properties of the material at both room and elevated temperatures, offering a viable [...] Read more.

Magnesium matrix composites formed by incorporating ceramic particles into a magnesium alloy matrix can effectively leverage the complementary properties of the matrix and reinforcement. This approach significantly enhances the mechanical properties of the material at both room and elevated temperatures, offering a viable solution to the inherent limitations of Mg alloys, such as insufficient absolute strength, stiffness, and poor heat resistance. This article reviews the latest research progress in the field of ceramic particle-reinforced magnesium matrix composites in recent years. First, the current research status of magnesium matrix composites reinforced with different types of ceramic particles is comprehensively summarized. Subsequently, it provides a summary and in-depth analysis of the principles, key technologies, and microstructural characteristics of both mainstream and emerging preparation processes, and discusses their advantages and disadvantages. Finally, the challenges in current research are analyzed, and future cutting-edge directions for developing high-performance ceramic particle-reinforced magnesium matrix composites are discussed. Full article

(This article belongs to the Special Issue High-Performance Lightweight Alloy Materials and Their Advanced Forming Technologies)

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24 pages, 3981 KB

Open AccessEditor’s ChoiceArticle

Predicting Low-Cycle Fatigue Life Using New Energy-Based Fatigue Damage Measures

by Stanisław Mroziński, Michał Piotrowski, Władysław Egner and Halina Egner

Materials 2026, 19(2), 352; https://doi.org/10.3390/ma19020352 - 15 Jan 2026

Cited by 1 | Viewed by 832

Abstract

This work investigates methods for predicting low-cycle fatigue life by employing new energy-based fatigue damage measures. The primary goal of this research is to evaluate whether fatigue life can be predicted based on an energy accumulation graph, proposed as a generalization of the [...] Read more.

This work investigates methods for predicting low-cycle fatigue life by employing new energy-based fatigue damage measures. The primary goal of this research is to evaluate whether fatigue life can be predicted based on an energy accumulation graph, proposed as a generalization of the isodamage lines concept. The efficiency of fatigue life predictions using this approach, derived from the empirical linear Palmgren–Miner hypothesis, is compared against the physically grounded Unified Mechanics Theory thermodynamic approach, which allows for general understanding of material degradation, in contrast to empirical approaches. The study also accounts for the influence of anisotropy resulting from the sheet rolling process on the fatigue response of S420M steel. Samples were tested in orientations both parallel to the rolling direction and perpendicular to the sheet surface. Microstructural analysis revealed a visible banded structure in the perpendicular samples, which is a consequence of anisotropy. The fatigue life of samples taken perpendicular to the sheet surface was lower than that of parallel samples. Verification of the linear Palmgren–Miner damage summation hypothesis, using both the classical fatigue chart and the cumulative energy chart, resulted in calculated fatigue life consistently higher than the experimental fatigue life in all cases. The reduction in fatigue life ranged from 40% (for total strain amplitude equal to 1.0%) to almost 290% for a strain amplitude of 0.25%. A comparative analysis of the unit loop energy shows that at all tested levels of strain amplitude, the unit loop energy of parallel samples is higher than that of samples perpendicular to the surface. Full article

(This article belongs to the Special Issue Advances in Fatigue Analysis and Numerical Simulation in Engineering Materials)

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19 pages, 3563 KB

Open AccessEditor’s ChoiceArticle

Numerical and Experimental Study of Laser Surface Modification Using a High-Power Fiber CW Laser

by Evaggelos Kaselouris, Alexandros Gosta, Efstathios Kamposos, Dionysios Rouchotas, George Vernardos, Helen Papadaki, Alexandros Skoulakis, Yannis Orphanos, Makis Bakarezos, Ioannis Fitilis, Nektarios A. Papadogiannis, Michael Tatarakis and Vasilis Dimitriou

Materials 2026, 19(2), 343; https://doi.org/10.3390/ma19020343 - 15 Jan 2026

Viewed by 1120

Abstract

This work presents a combined numerical and experimental investigation into the laser machining of aluminum alloy Al 1050 H14 using a high-power Continuous Wave (CW) fiber laser. Advanced three-dimensional, coupled thermal–structural Finite Element Method (FEM) simulations are developed to model key laser–material interaction [...] Read more.

This work presents a combined numerical and experimental investigation into the laser machining of aluminum alloy Al 1050 H14 using a high-power Continuous Wave (CW) fiber laser. Advanced three-dimensional, coupled thermal–structural Finite Element Method (FEM) simulations are developed to model key laser–material interaction processes, including laser-induced plastic deformation, laser etching, and engraving. Cases for both static single-shot and dynamic linear scanning laser beams are investigated. The developed numerical models incorporate a Gaussian heat source and the Johnson–Cook constitutive model to capture elastoplastic, damage, and thermal effects. The simulation results, which provide detailed insights into temperature gradients, displacement fields, and stress–strain evolution, are rigorously validated against experimental data. The experiments are conducted on an integrated setup comprising a 2 kW TRUMPF CW fiber laser hosted on a 3-axis CNC milling machine, with diagnostics including thermal imaging, thermocouples, white-light interferometry, and strain gauges. The strong agreement between simulations and measurements confirms the predictive capability of the developed FEM framework. Overall, this research establishes a reliable computational approach for optimizing laser parameters, such as power, dwell time, and scanning speed, to achieve precise control in metal surface treatment and modification applications. Full article

(This article belongs to the Special Issue Fabrication of Advanced Materials)

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20 pages, 2326 KB

Open AccessEditor’s ChoiceArticle

Stability of Composite Plates with a Dense System of Ribs in Two Directions

by Jakub Marczak, Martyna Rabenda and Bohdan Michalak

Materials 2026, 19(2), 322; https://doi.org/10.3390/ma19020322 - 13 Jan 2026

Cited by 1 | Viewed by 355

Abstract

This paper presents an easy-to-use analytical method for stability analysis of composite plates with dense bidirectional microstructure. The main characteristic feature of such a defined composite is that due to its periodic nature the obtainable governing partial differential equations are characterised by discontinuous, [...] Read more.

This paper presents an easy-to-use analytical method for stability analysis of composite plates with dense bidirectional microstructure. The main characteristic feature of such a defined composite is that due to its periodic nature the obtainable governing partial differential equations are characterised by discontinuous, strongly oscillating coefficients. Such cases bring many difficulties during derivation of their solution. In order to simplify calculations, the initial governing equations are transformed with the use of the tolerance averaging technique, so a system of partial differential equations with constant coefficients is obtained. The most important finding of the presented work is that the form of the mentioned equations is similar to the classic equations, which describe the stability issue of the thin homogeneous plate. Consequently, the analytical solution to such issues is easily obtainable. Moreover, when compared to, for example, finite element method (FEM) analysis, it requires substantially less computation resources, which can be perceived as its superior feature. Therefore, the proposed method is convenient for engineering applications. In this paper, a comparative analysis of the results obtained from the proposed analytical models with the results obtained from the FEM has been carried out. The impact of materials and dimensions of microstructure on the values of critical normal and shear forces has also been analysed. Full article

(This article belongs to the Section Mechanics of Materials)

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28 pages, 1597 KB

Open AccessEditor’s ChoiceArticle

The Influence of Material and Process Parameters on Pressure Agglomeration and Properties of Pellets Produced from Torrefied Forest Logging Residues

by Arkadiusz Gendek, Monika Aniszewska, Paweł Tylek, Grzegorz Szewczyk, Jozef Krilek, Iveta Čabalová, Jan Malaťák, Jiří Bradna and Katalin Szakálos-Mátyás

Materials 2026, 19(2), 317; https://doi.org/10.3390/ma19020317 - 13 Jan 2026

Cited by 2 | Viewed by 1000

Abstract

Pellets produced from raw or torrefied shredded logging residues have been investigated in the study. The research material came from pine and spruce stands in Poland, Slovakia, Czechia and Hungary. Torrefaction temperatures (T_t) of 250, 300, and 400 °C were [...] Read more.

Pellets produced from raw or torrefied shredded logging residues have been investigated in the study. The research material came from pine and spruce stands in Poland, Slovakia, Czechia and Hungary. Torrefaction temperatures (T_t) of 250, 300, and 400 °C were applied. Before pressure agglomeration, 3% wheat flour was added to the torrefaction material as a binding agent. Pellets with a diameter of 8 mm were produced at constant humidity, compaction pressure (P) of 140 or 180 MPa and agglomeration temperature (T_a) of 100, 120 or 140 °C. The produced pellets were assessed for their physicomechanical parameters (density, radial compressive strength, compression ratio, modulus of elasticity), chemical parameters (extractive compounds, cellulose, lignin) and energy parameters (ash content, elemental composition, calorific value). The results were subjected to basic statistical analysis and multi-way ANOVA. The produced pellets varied in physical, mechanical, chemical and energy properties. A significant effect of torrefaction temperature, agglomeration temperature and compaction pressure on the results was observed. In terms of physicomechanical parameters, the best pellets were produced from the raw material, while in terms of energy parameters, those produced from the torrefied material were superior. Pellets of satisfactory quality produced from torrefied logging residues could be obtained at T_t = 250 °C, T_a = 120 °C and P = 180 MPa. Pellets with specific density of approximately 1.1 g·cm⁻³, radial compressive strength of 3–3.5 MPa, modulus of elasticity of 60–80 MPa and calorific value of 20.3–23.8 MJ·kg⁻¹ were produced in the process. Full article

(This article belongs to the Special Issue Catalysis for Biomass Materials Conversion)

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15 pages, 13053 KB

Open AccessEditor’s ChoiceArticle

Development of Ti-Nb-Mo-Zr Alloys with Low Modulus and Excellent Plasticity for Biomedical Applications

by Sen Yang, Zhiyuan Jia, Xueyan Song, Junyang He and Xiaoyong Zhang

Materials 2026, 19(2), 325; https://doi.org/10.3390/ma19020325 - 13 Jan 2026

Cited by 6 | Viewed by 2083

Abstract

Metastable β titanium alloys with low elastic modulus and excellent plasticity represent highly attractive materials for biomedical stent application. Our work shows that Zr plays a crucial role in regulating β stability to significantly reduce the modulus and enhance plasticity. A series of [...] Read more.

Metastable β titanium alloys with low elastic modulus and excellent plasticity represent highly attractive materials for biomedical stent application. Our work shows that Zr plays a crucial role in regulating β stability to significantly reduce the modulus and enhance plasticity. A series of Ti-25Nb-2Mo-xZr (x = 0, 3, 9, 12 wt%) alloys were designed based on the d-electron theory, and the influence of Zr content on the microstructure, mechanical properties, and deformation mechanism were systematically investigated. The results demonstrated that as the Zr content increases, the β phase stability was significantly enhanced. This leads to, first, the suppressed formation of the high modulus α″ phase and ω phase, which results in the decrease in apparent overall elastic modulus. Second, the dominant mode of deformation shifts from martensite dislocation slip (0Zr) to martensitic variant reorientation (3Zr), then to stress-induced martensite transform (SIMT, 9Zr), and finally to a combination of SIMT and deformation twinning (12Zr). Such shifting effectively increases the alloy’s tensile plasticity. Among the series, the Ti-25Nb-2Mo-12Zr alloy exhibited the lowest elastic modulus of 56.3 GPa, together with the highest elongation to failure of 48.2%, demonstrating that the alloy possesses considerable potential for biomedical applications. Full article

(This article belongs to the Special Issue Research on Performance Improvement of Advanced Alloys (2nd Edition))

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11 pages, 2682 KB

Open AccessEditor’s ChoiceArticle

A Metasticker Composed of Indium-Tin-Oxide-Square-Fractal Rings for Broadband Absorption

by Min-Sik Kim, Won-Woo Choi and Yongjune Kim

Materials 2026, 19(2), 297; https://doi.org/10.3390/ma19020297 - 12 Jan 2026

Viewed by 1235

Abstract

This study proposes design and fabrication methods for an electromagnetic metasurface absorber (MA) that absorbs electromagnetic waves using a metasticker attached on a dielectric substrate blocked by a copper sheet. To guarantee a high design freedom as well as make the absorption bandwidth [...] Read more.

This study proposes design and fabrication methods for an electromagnetic metasurface absorber (MA) that absorbs electromagnetic waves using a metasticker attached on a dielectric substrate blocked by a copper sheet. To guarantee a high design freedom as well as make the absorption bandwidth (BW) as broad as possible, a square-fractal ring is chosen as the metapattern, and its design is optimized using a genetic algorithm. To fabricate the square-fractal rings in a simple manner, an indium-tin-oxide film is cut by using a laser-cutting machine. Then, the metasticker is fabricated by assembling the metapatterns on a double-sided adhesive film which could be attached on the dielectric substrate using the opposite side of the film. From measured results of the finalized MA of which damaged regions caused by the laser-cutting process are compensated in the design process, a broad

- 10

dB reflectance BW is confirmed from 4.39 to 7.51 GHz of which the fractional BW is 52.44% for the normal incidence. Moreover, a fractional BW of 4.35% is measured in a wide incident angle range from

0 °

to

60 °

for both the transverse electric and the transverse magnetic polarizations simultaneously. Full article

(This article belongs to the Special Issue Advances in Metamaterials: Structure, Properties and Applications—Second Edition)

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27 pages, 11480 KB

Open AccessEditor’s ChoiceArticle

Design and Characterization of Gelatin-Based Interpenetrating Polymer Networks for Biomedical Use: Rheological, Thermal, and Physicochemical Evaluation

by Roberto Grosso, Fátima Díaz-Carrasco, Elena Vidal-Nogales, M.-Violante de-Paz, M.-Jesús Díaz-Blanco and Elena Benito

Materials 2026, 19(2), 289; https://doi.org/10.3390/ma19020289 - 10 Jan 2026

Viewed by 1135

Abstract

Tissue engineering is a multidisciplinary field that aims to address tissue and organ failure by integrating scientific, engineering, and medial expertise. Gelatin is valued in this field for its biocompatibility; however, it faces thermal and mechanical weaknesses that limit its biomedical utility. This [...] Read more.

Tissue engineering is a multidisciplinary field that aims to address tissue and organ failure by integrating scientific, engineering, and medial expertise. Gelatin is valued in this field for its biocompatibility; however, it faces thermal and mechanical weaknesses that limit its biomedical utility. This work proposes a strategy for improving gelatin properties by fabricating semi-interpenetrating polymer networks via in situ Diels–Alder crosslinking within gelatin colloidal solutions. Ten systems with variable polymer concentrations (2–4%) and crosslinking degrees (2–5%) were prepared and characterized. Rheological analysis revealed that elastic modulus, zero-shear viscosity, and complex viscosity were substantially enhanced, being especially dependent on the crosslinking degree, while critical strain values mostly depended on gelatin concentration. The incorporation of a synthetic Diels–Alder-crosslinked network also improved the thermal stability of gelatin hydrogels, particularly at physiological temperatures. Additionally, these systems exhibit favorable buoyancy, swelling and biodegradation profiles. Collectively, the resultant hydrogels are cytocompatible, solid-like, and mechanically robust, allowing for further tunability of their properties for specific biomedical uses, such as injectable matrices, load-bearing scaffolds for tissue repair, and 3D bioinks. Full article

(This article belongs to the Special Issue Functional Hydrogel for Biomedical Applications: Progress, Challenges, and Opportunities)

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14 pages, 2314 KB

Open AccessEditor’s ChoiceArticle

Influence of Mo and Ni Alloying on Recrystallization Kinetics and Phase Transformation in Quenched and Tempered Thick Steel Plates

by Xabier Azpeitia, Unai Mayo, Nerea Isasti, Eric Detemple, Hardy Mohrbacher and Pello Uranga

Materials 2026, 19(2), 290; https://doi.org/10.3390/ma19020290 - 10 Jan 2026

Viewed by 822

Abstract

The production of heavy gauge quenched and tempered steel plates requires alloying strategies that ensure adequate hardenability and microstructural uniformity under limited cooling rates. Molybdenum (Mo) and nickel (Ni) are key elements in this context, as they influence both hot-working behavior and phase [...] Read more.

The production of heavy gauge quenched and tempered steel plates requires alloying strategies that ensure adequate hardenability and microstructural uniformity under limited cooling rates. Molybdenum (Mo) and nickel (Ni) are key elements in this context, as they influence both hot-working behavior and phase transformation kinetics. This study investigates the effect of Mo (0.25–0.50 wt%) and Ni (0–1.00 wt%) additions on static recrystallization and transformation behavior using laboratory thermomechanical simulations representative of thick plate rolling conditions. Multipass and double-hit torsion tests were performed to determine the non-recrystallization temperature (Tnr) and quantify softening kinetics, while dilatometry was employed to construct Continuous Cooling Transformation (CCT) diagrams and assess hardenability. Results indicate that Mo significantly increases Tnr and delays recrystallization through a solute drag mechanism, whereas Ni exerts a minor but measurable effect, likely associated with stacking fault energy rather than classical solute drag. Both elements reduce ferrite and bainite transformation temperatures, enhancing hardenability; however, Mo alone cannot suppress ferrite formation at practical cooling rates, requiring combined Mo–Ni additions to achieve fully martensitic microstructures. These findings provide insight into alloy design for thick plate applications and highlight the limitations of existing predictive models for Ni-containing steels. Full article

(This article belongs to the Section Manufacturing Processes and Systems)

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13 pages, 2840 KB

Open AccessEditor’s ChoiceArticle

Effect of Fe/Ni Microalloying on Interface Regulation of SiC/Al Composites: Molecular Dynamics Simulation and Experiments

by Tianpeng Song, Xiaoshuang Du, Tao Xia, Yong Liu, Jingchuan Zhu and Xuexi Zhang

Materials 2026, 19(2), 283; https://doi.org/10.3390/ma19020283 - 9 Jan 2026

Cited by 2 | Viewed by 819

Abstract

SiC/Al matrix composites are prone to forming brittle Al₄C₃ phase via interfacial reactions during fabrication, which severely limits their mechanical properties and engineering applications. Microalloying is an effective method to inhibit this brittle phase, yet the interfacial mechanism of alloying [...] Read more.

SiC/Al matrix composites are prone to forming brittle Al₄C₃ phase via interfacial reactions during fabrication, which severely limits their mechanical properties and engineering applications. Microalloying is an effective method to inhibit this brittle phase, yet the interfacial mechanism of alloying elements at the atomic scale remains unclear. Centered on molecular dynamics simulation combined with experimental verification, this study systematically investigates the laws of Fe and Ni microalloying on the interface regulation and mechanical property optimization of SiC/Al composites. Simulation results show that Fe and Ni atoms tend to segregate at the SiC/Al interface, which can suppress interfacial reactions, promote dislocation nucleation and proliferation, induce new dislocation types, and achieve the synergistic improvement of strength and ductility—with Ni exhibiting a more prominent strengthening effect. Composites prepared by the pressure infiltration-hot extrusion process show no Al₄C₃ phase in phase detection. Mechanical property tests confirm that Fe and Ni microalloying can effectively enhance the comprehensive performance of the materials, among which Ni increases the strength–ductility product by 54%. This study clarifies the interfacial regulation mechanism of Fe and Ni microalloying at the atomic scale, providing theoretical guidance and experimental support for the microalloying design of SiC/Al composites. Full article

(This article belongs to the Special Issue Research on Performance Improvement of Advanced Alloys (2nd Edition))

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12 pages, 3990 KB

Open AccessEditor’s ChoiceCommunication

Microstructure-Property Regulation in a Large-Size Mg-9.4Gd-5.8Y-1Zn-0.5Zr Alloy by Differential Phase Electromagnetic Semi-Continuous Casting and Homogenization

by Yonghui Jia, Fangkun Ning, Yao Cheng, Yunchang Xin and Weitao Jia

Materials 2026, 19(2), 282; https://doi.org/10.3390/ma19020282 - 9 Jan 2026

Cited by 1 | Viewed by 628

Abstract

Based on a novel semi-continuous casting mold with independent primary cooling regulation, a large-size Mg-9.4Gd-5.8Y-1Zn-0.5Zr alloy billet (Ø330 mm) was successfully fabricated via differential phase electromagnetic vibration casting. This process significantly improved microstructural homogeneity, with grain sizes ranging from 117 µm to 130 [...] Read more.

Based on a novel semi-continuous casting mold with independent primary cooling regulation, a large-size Mg-9.4Gd-5.8Y-1Zn-0.5Zr alloy billet (Ø330 mm) was successfully fabricated via differential phase electromagnetic vibration casting. This process significantly improved microstructural homogeneity, with grain sizes ranging from 117 µm to 130 µm across the billet and elemental segregation of Gd and Y below 3%. Homogenization at 520 °C for 5 h effectively dissolved grain boundary eutectic phases; promoted diffusion of Gd, Y, and Zn into the α-Mg matrix; and stimulated the precipitation of fine LPSO lamellae. These microstructural improvements resulted in an excellent tensile strength of 208.4 MPa and elongation of 24.4%, demonstrating an optimal strength–ductility balance achieved through precise thermal processing. Full article

(This article belongs to the Special Issue Microstructure Engineering of Metals and Alloys, 3rd Edition)

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20 pages, 5117 KB

Open AccessEditor’s ChoiceArticle

Thin HPFRC Jackets for Axially Loaded RC Columns: Mechanical Behavior and Efficacy of Strengthening

by Maria Dolores Criado Fernández, Sonia Martínez de Mingo and Ana Almerich-Chulia

Materials 2026, 19(2), 220; https://doi.org/10.3390/ma19020220 - 6 Jan 2026

Cited by 2 | Viewed by 760

Abstract

The environmental impact of the construction sector underscores the urgent need for sustainable solutions to extend the service life of existing structures. This study explores High-Performance Fiber-Reinforced Concrete (HPFRC) for strengthening reinforced-concrete (RC) columns subjected to axial compression. Twelve RC columns were tested, [...] Read more.

The environmental impact of the construction sector underscores the urgent need for sustainable solutions to extend the service life of existing structures. This study explores High-Performance Fiber-Reinforced Concrete (HPFRC) for strengthening reinforced-concrete (RC) columns subjected to axial compression. Twelve RC columns were tested, each 1200 mm high and with varying cross-sectional shapes (circular, square, and rectangular). Strengthening was achieved using thin HPFRC jackets (less than 30 mm thick), applied without additional internal reinforcement and following simple surface preparation techniques such as sandblasting. Full-height jacketing significantly improved axial load capacity. Its effectiveness did not decrease with the shape of the cross-section, with square columns showing up to a 105% increase and rectangular ones up to 87%, compared to unstrengthened columns with the same concrete strength. The highest improvement was observed in the square column with full-height jacketing and the most significant geometric strengthening ratio (52.6%), which doubled its axial capacity. This ratio was directly related to performance gains. Although ductility gains were limited, the full-jacketed specimens did not fail explosively: their failure mode was progressive, providing a useful warning before collapse. HPFRC jacketing can be especially effective for non-circular columns, outperforming FRP jacketing and eliminating the need for additional protective layers against impact or fire. Full article

(This article belongs to the Special Issue Advances in Ultra-High Performance Concretes and Cementitious Composites)

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16 pages, 2638 KB

Open AccessEditor’s ChoiceArticle

Application of Machine Learning Models in Predicting Vibration Frequencies of Thin Variable Thickness Plates

by Łukasz Domagalski and Izabela Kowalczyk

Materials 2026, 19(1), 205; https://doi.org/10.3390/ma19010205 - 5 Jan 2026

Cited by 3 | Viewed by 1576

Abstract

This study investigates the application of machine learning (ML) techniques for predicting vibration frequencies of thin rectangular plates with variable thickness. Traditional optimization methods, such as genetic algorithms, require repeated solutions of the plate vibration eigenproblem using finite element (FE) analysis, which is [...] Read more.

This study investigates the application of machine learning (ML) techniques for predicting vibration frequencies of thin rectangular plates with variable thickness. Traditional optimization methods, such as genetic algorithms, require repeated solutions of the plate vibration eigenproblem using finite element (FE) analysis, which is computationally expensive. To reduce this cost, a surrogate model based on artificial neural networks (ANNs) is proposed as an efficient alternative. The dataset includes variations in plate geometry, boundary conditions, and thickness distribution, encoded numerically for model training. ANN architecture and hyperparameters—such as the number of hidden layers, neurons per layer, and activation functions—were systematically tuned to achieve high prediction accuracy while avoiding overfitting. Data preprocessing steps, including standardization and scaling, were applied to improve model stability. Performance was evaluated using metrics such as RMSE and R². The results demonstrate that ANNs can accurately predict eigenvalues with significantly reduced computational effort compared to FE analysis. This approach offers a practical solution for integrating machine learning into structural optimization workflows. Full article

(This article belongs to the Special Issue Advances in Machine Learning for the Prediction of Construction Materials Properties)

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28 pages, 6311 KB

Open AccessEditor’s ChoiceArticle

Machine Learning-Assisted Optimisation of the Laser Beam Powder Bed Fusion (PBF-LB) Process Parameters of H13 Tool Steel Fabricated on a Preheated to 350 ^∘C Building Platform

by Katsiaryna Kosarava, Paweł Widomski, Michał Ziętala, Daniel Dobras, Marek Muzyk and Bartłomiej Adam Wysocki

Materials 2026, 19(1), 210; https://doi.org/10.3390/ma19010210 - 5 Jan 2026

Viewed by 2274

Abstract

This study presents the first application of Machine Learning (ML) models to optimise Powder Bed Fusion using Laser Beam (PBF-LB) process parameters for H13 steel fabricated on a 350 °C preheated building platform. A total of 189 cylindrical specimens were produced for training [...] Read more.

This study presents the first application of Machine Learning (ML) models to optimise Powder Bed Fusion using Laser Beam (PBF-LB) process parameters for H13 steel fabricated on a 350 °C preheated building platform. A total of 189 cylindrical specimens were produced for training and testing machine learning (ML) models using variable process parameters: laser power (250–350 W), scanning speed (1050–1300 mm/s), and hatch spacing (65–90

μ

m). Eight ML models were investigated: 1. Support Vector Regression (SVR), 2. Kernel Ridge Regression (KRR), 3. Stochastic Gradient Descent Regressor, 4. Random Forest Regressor (RFR), 5. Extreme Gradient Boosting (XGBoost), 6. Extreme Gradient Boosting with limited depth (XGBoost LD), 7. Extra Trees Regressor (ETR) and 8. Light Gradient Boosting Machine (LightGBM). All models were trained using the Fast Library for Automated Machine Learning & Tuning (FLAML) framework to predict the relative density of the fabricated samples. Among these, the XGBoost model achieved the highest predictive accuracy, with a coefficient of determination

R^{2} = 0.977

, mean absolute percentage error MAPE = 0.002, and mean absolute error MAE = 0.017. Experimental validation was conducted on 27 newly fabricated samples using ML predicted process parameters. Relative densities exceeding 99.6% of the theoretical value (7.76 g/cm³) for all models except XGBoost LD and KRR. The lowest MAE = 0.004 and the smallest difference between the ML-predicted and PBF-LB validated density were obtained for samples made with LightGBM-predicted parameters. Those samples exhibited a hardness of 604 ± 13 HV0.5, which increased to approximately 630 HV0.5 after tempering at 550 °C. The LightGBM optimised parameters were further applied to fabricate a part of a forging die incorporating internal through-cooling channels, demonstrating the efficacy of machine learning-guided optimisation in achieving dense, defect-free H13 components suitable for industrial applications. Full article

(This article belongs to the Special Issue Multiscale Design and Optimisation for Metal Additive Manufacturing)

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21 pages, 7512 KB

Open AccessEditor’s ChoiceArticle

Controlled Synthesis and Formation Mechanism of Uniformly Sized Spherical CeO₂ Nanoparticles

by Jiayue Xie, Kai Feng, Rui Ye, Maokui Wang, Yunci Wang, Xing Fan and Renlong Liu

Materials 2026, 19(1), 211; https://doi.org/10.3390/ma19010211 - 5 Jan 2026

Cited by 5 | Viewed by 1932

Abstract

As the core abrasive in chemical mechanical polishing (CMP) processes, the morphology, size uniformity, and chemical reactivity of CeO₂ nanoparticles (NPs) are crucial factors determining the surface precision and yield of devices. In this work, a KNO₃–LiNO₃ eutectic molten [...] Read more.

As the core abrasive in chemical mechanical polishing (CMP) processes, the morphology, size uniformity, and chemical reactivity of CeO₂ nanoparticles (NPs) are crucial factors determining the surface precision and yield of devices. In this work, a KNO₃–LiNO₃ eutectic molten salt was used as the reaction medium. By systematically adjusting key processing parameters (such as the type of cerium source, the species and dosage of surfactants, and calcination conditions), the regulatory effects of these factors on particle growth mechanisms were clarified. This adjustment enabled the controlled synthesis of spherical CeO₂ NPs with customized morphology, particle size, and surface defect states. The multi-stage reaction process of the precursor during calcination was identified by applying thermal analysis techniques, including TG-DSC and TG-FTIR. This process includes dehydration, ion exchange, and thermal decomposition. Microstructural analysis shows that the type and dosage of the cerium source and template agent significantly affect the uniformity of particle size and spherical morphology. Moreover, by using an optimized process with a heating rate of 6 °C/min and maintaining at 400 °C for 3 h, spherical CeO₂ NPs with an average particle size of 60 nm, uniform size distribution, and high sphericity were successfully synthesized via a single-step calcination process. Based on these findings, a further proposal was put forward regarding a crystal growth mechanism mediated by micelle-directed assembly and oriented attachment. This method only requires a single calcination step, has mild reaction conditions, and involves a simple process without the need for specialized equipment—features that show great potential for scalable production. It provides both a theoretical basis and experimental support for the controlled preparation of high-performance CeO₂ abrasives. Full article

(This article belongs to the Section Advanced Nanomaterials and Nanotechnology)

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25 pages, 1939 KB

Open AccessEditor’s ChoiceArticle

Application of Potato Peels as an Unconventional Sorbent for the Removal of Anionic and Cationic Dyes from Aqueous Solutions

by Tomasz Jóźwiak, Urszula Filipkowska, Anna Nowicka and Jarosław Kaźmierczak

Materials 2026, 19(1), 185; https://doi.org/10.3390/ma19010185 - 4 Jan 2026

Cited by 2 | Viewed by 1498

Abstract

The aim of this study was to investigate the sorption efficiency of anionic dyes—Reactive Yellow 84 (RY84) and Reactive Black 5 (RB5)—and cationic dyes—Red 46 (BR46) and Basic Violet 10 (BV10)—onto potato peels (Solanum tuberosum L.). The research scope included characterization of [...] Read more.

The aim of this study was to investigate the sorption efficiency of anionic dyes—Reactive Yellow 84 (RY84) and Reactive Black 5 (RB5)—and cationic dyes—Red 46 (BR46) and Basic Violet 10 (BV10)—onto potato peels (Solanum tuberosum L.). The research scope included characterization of the sorbent material (pH_PZC, FTIR), the effect of pH on dye sorption efficiency, kinetics (pseudo-first-order and pseudo-second-order models, intraparticle diffusion model), and studies on the sorbent’s maximum sorption capacity (Langmuir 1 and 2, and Freundlich isotherms). The point of zero charge (pH_PZC) for potato peels was determined to be pH_PZC = 6.43, indicating a slightly acidic character of the material. The sorption efficiency for RB5, RY84, and BV10 was highest at pH 2, while the efficiency for BR46 was highest at pH 6. The time required to reach sorption equilibrium on the tested sorbent increased with the initial dye concentration and ranged from 180 to 270 min for RB5, RY84, and BV10, and from 45 to 210 min for BR46. The maximum sorption capacity of this material was found to be 20.85 ± 0.33 mg/g and 21.63 ± 0.34 mg/g for RB5 and RY84, respectively, and 10.28 ± 0.24 mg/g and 27.15 ± 0.87 mg/g for BV10 and BR46, respectively. Full article

(This article belongs to the Special Issue Advanced Technologies and Materials for Wastewater Treatment)

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21 pages, 7862 KB

Open AccessEditor’s ChoiceArticle

Laser Deposition of Metal Oxide Structures for Gas Sensor Applications

by Nikolay Nedyalkov, Anna Dikovska, Tina Dilova, Genoveva Atanasova, Reni Andreeva and Georgi Avdeev

Materials 2026, 19(1), 176; https://doi.org/10.3390/ma19010176 - 3 Jan 2026

Cited by 1 | Viewed by 1085

Abstract

This work presents results on laser-induced fabrication of metal and oxide structures on glass substrates. The Laser-Induced Reverse Transfer (LIRT) technique is applied using Zn and Sn, sintered ZnO and SnO₂, and oxide composite targets. The processing is performed by nanosecond [...] Read more.

This work presents results on laser-induced fabrication of metal and oxide structures on glass substrates. The Laser-Induced Reverse Transfer (LIRT) technique is applied using Zn and Sn, sintered ZnO and SnO₂, and oxide composite targets. The processing is performed by nanosecond pulses of a Nd:YAG laser system operated at wavelength of 1064 nm. Detailed analyses of the deposited material morphology, composition and structure are presented, as the role of the processing conditions is revealed. It is found that at the applied conditions of using up to five laser pulses, the deposited material is composed of a nanostructured film covered in microsized nanoparticle clusters or droplets. The use of metal targets leads to formation of structures composed of metal and oxide phases. The adhesion test shows that part of the deposited material is stably adhered to the substrate surface. It is demonstrated that the deposited materials can be used as resistive gas sensors with sensitivity to NH₃, CO, ethanol, acetone and N₂O, at concentrations of 30 ppm. The ability of the method to deposit composite structures that consist of a mixture of both investigated oxides is also demonstrated. Full article

(This article belongs to the Special Issue Advances in Plasma and Laser Engineering (Third Edition))

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23 pages, 9412 KB

Open AccessEditor’s ChoiceArticle

Ballistic Performance of 7A52/7A62 Aluminum Alloy Laminates: A Numerical Investigation of Configuration Effect

by Qunjiao Wang, Meilin Yin, Jiangong Zhou, Xinyu Liu, Hui Zhang, Ruibin Mei, Zejun Chen, Yu Cao, Qiang Wang, Fuguan Cong and Yunlong Zhang

Materials 2026, 19(1), 179; https://doi.org/10.3390/ma19010179 - 3 Jan 2026

Viewed by 1019

Abstract

This study presents a systematic numerical investigation into the ballistic performance of 7A52/7A62 aluminum alloy laminated plates with varying configurations. The dynamic mechanical behavior of the base alloys, 7A52 and 7A62, was first characterized experimentally, and the corresponding Johnson-Cook (J-C) constitutive parameters were [...] Read more.

This study presents a systematic numerical investigation into the ballistic performance of 7A52/7A62 aluminum alloy laminated plates with varying configurations. The dynamic mechanical behavior of the base alloys, 7A52 and 7A62, was first characterized experimentally, and the corresponding Johnson-Cook (J-C) constitutive parameters were calibrated. Using the calibrated J-C model, a series of numerical simulations were performed on several structural configurations, including single-layer (7A52-A, 7A62-B), double-layer (AB, BA), and four-layer laminates (ABAB, BAAB, ABBA, BABA). The results demonstrate that four-layer laminates exhibit markedly better ballistic performance than monolithic and double-layer plates. Among them, the ABAB stacking sequence—arranged in an alternating soft–hard–soft–hard pattern—shows the optimal performance, yielding a residual projectile velocity of only 256 m/s. This represents an approximately 27% reduction compared to the monolithic high-strength 7A62 plate. The overall ranking of ballistic performance is as follows: ABAB > BAAB > ABBA > BABA. Energy-based analysis further indicates that multi-interface delamination, coupled with plastic deformation and damage evolution, improves the energy-absorption efficiency of the laminated plates and thus enhances their ballistic resistance. This study offers valuable guidance for the lightweight design of laminated 7XXX-series aluminum alloy protective plates. Full article

(This article belongs to the Special Issue Advances in Al/Mg/Cu Alloys and Their Composites: Welding, Additive Manufacturing, Heterogeneous Microstructures, and Mechanical Properties)

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29 pages, 9334 KB

Open AccessEditor’s ChoiceReview

Research Progress on Characterization Techniques for the Corrosion Behavior of Bronze Artifacts

by Hongliang Li, Yongdi Zhao, Xiaohui Wang, Hanjie Guo, Chao Ren, Chunyan Liu and Li Xiang

Materials 2026, 19(1), 162; https://doi.org/10.3390/ma19010162 - 2 Jan 2026

Cited by 4 | Viewed by 1993

Abstract

Ancient bronzes are invaluable for studying the cultures and history of ancient societies around the world. However, corrosion can diminish their research and aesthetic value, as well as affect their longevity. Therefore, it is crucial to study the corrosion behavior and mechanisms of [...] Read more.

Ancient bronzes are invaluable for studying the cultures and history of ancient societies around the world. However, corrosion can diminish their research and aesthetic value, as well as affect their longevity. Therefore, it is crucial to study the corrosion behavior and mechanisms of these artifacts using advanced characterization techniques. This article provides a systematic review of the corrosion behavior of bronze artifacts and the advanced characterization techniques employed in their study. It summarizes the corrosion mechanisms of bronze artifacts and the factors affecting corrosion, including composition, structure, and the external environment. It also describes advanced analytical techniques for characterizing corrosion products and mechanisms, such as X-ray fluorescence (XRF), laser ablation coupled to quadrupole mass spectrometry (LAMQS), X-ray tomography (CT), and neutron diffraction. Bronze corrosion studies can be enhanced by the integration of artificial intelligence (AI) and machine learning (ML). Finally, it discusses potential future research directions in the field of bronze artifact corrosion and conservation. Full article

(This article belongs to the Section Corrosion)

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15 pages, 2113 KB

Open AccessEditor’s ChoiceArticle

Enhanced Toluene Combustion over Cryptomelane Catalysts: Influence of Cu Doping on Physicochemical Properties and Catalytic Performance

by Jakub Mokrzycki, Joanna Kryściak-Czerwenka, Dorota Duraczyńska, Mateusz Marzec and Robert Karcz

Materials 2026, 19(1), 159; https://doi.org/10.3390/ma19010159 - 2 Jan 2026

Viewed by 1486

Abstract

The catalytic combustion of toluene over cryptomelane and Cu-doped cryptomelane catalysts was investigated to evaluate the effect of copper incorporation on catalytic performance. It was found that a small addition of Cu into the cryptomelane framework resulted in a notable decrease in the [...] Read more.

The catalytic combustion of toluene over cryptomelane and Cu-doped cryptomelane catalysts was investigated to evaluate the effect of copper incorporation on catalytic performance. It was found that a small addition of Cu into the cryptomelane framework resulted in a notable decrease in the temperature of 90% toluene conversion. To elucidate the structure–activity relationship, the catalysts were comprehensively characterized using XRD, FTIR, SEM-EDS, N₂ physisorption, XRF, XPS, O₂-TPD, and H₂-TPR techniques. The results revealed that Cu doping modifies the physicochemical properties of cryptomelane, most importantly the share of lattice and surface oxygen species, enhancing redox behavior and oxygen mobility, which in turn improves catalytic activity. For the lowest dose of Cu, both the temperatures of 50 and 90% conversion were found to be lowest among investigated catalyst series: 180 and 195 °C, respectively. These findings highlight the potential of Cu-doped cryptomelane as an efficient catalyst for the abatement of volatile organic compounds. Full article

(This article belongs to the Special Issue Catalysis: Where We Are and Where We Go)

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15 pages, 3625 KB

Open AccessEditor’s ChoiceArticle

Effect of Iron Site Substitution on Magneto-Optical Properties of Bi-Substituted Garnets for Magnetic Hologram Memory

by Sumiko Bharti Singh Chauhan, Yuichi Nakamura, Shinichiro Mito and Lim Pang Boey

Materials 2026, 19(1), 151; https://doi.org/10.3390/ma19010151 - 1 Jan 2026

Cited by 2 | Viewed by 1385

Abstract

We have developed a magnetic holographic memory using transparent bismuth-substituted rare-earth iron garnet as a next-generation optical memory. To realize this, a magnetic garnet with a large Faraday rotation angle and a moderately small extinction coefficient is required. In this study, we investigated [...] Read more.

We have developed a magnetic holographic memory using transparent bismuth-substituted rare-earth iron garnet as a next-generation optical memory. To realize this, a magnetic garnet with a large Faraday rotation angle and a moderately small extinction coefficient is required. In this study, we investigated the effect of Al or Ga substitution for the iron site of bismuth-substituted yttrium iron garnet (Bi/YIG) films on their magneto-optical properties. The Faraday rotation angle decreased with the amount of substitution, x, increase, for both Al- and Ga-substituted Bi/YIG, and a reversal of sign of rotation angle was only observed for Ga-substituted Bi/YIG, indicating a compensation composition. In the Al-substituted sample, due to small squareness, the residual Faraday rotation angle at zero magnetic field, |θ_R,res|, gradually decreased above x = 0.5, whereas in the Ga-substituted sample, the squareness ratio increased with increasing substitution up to x = 2.0, and thus showed a peak at x = 1.5. The Curie temperature and extinction coefficient were reduced with increasing substitution amount. As a result of a decrease in extinction coefficient, k, the high figure of merit, (|θ_R,res|/2πk) · λ was obtained around x = 1.5~1.9 for Ga and x = 2.1 for Al, while it was smaller than that of Bi/RIG we usually used. Full article

(This article belongs to the Section Optical and Photonic Materials)

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19 pages, 3591 KB

Open AccessEditor’s ChoiceArticle

Comparison of the Effectiveness of Paper Strengthening with Gelatin, Klucel G, and Tylose Solutions in Combination with Deacidification Using Magnesium Hydroxide Nanoparticles

by Renata Wojech, Aleksandra Kwiatkowska, Grzegorz Cofta and Adam Wójciak

Materials 2026, 19(1), 126; https://doi.org/10.3390/ma19010126 - 30 Dec 2025

Cited by 2 | Viewed by 1408

Abstract

The manuscript concerns modern methods of preserving historical papers and presents research focusing on the effectiveness of paper strengthening with gelatin, Klucel G, and Tylose solutions in combination with deacidification using magnesium hydroxide nanoparticles. The aim of these procedures is to extend the [...] Read more.

The manuscript concerns modern methods of preserving historical papers and presents research focusing on the effectiveness of paper strengthening with gelatin, Klucel G, and Tylose solutions in combination with deacidification using magnesium hydroxide nanoparticles. The aim of these procedures is to extend the durability of historical records on papers, which are an important part of humanity’s cultural heritage. Gelatin and Klucel G dissolved in propyl alcohol were used simultaneously with the dispersion of Mg(OH)₂ nanoparticles, and Tylose dissolved in water was applied after deacidification in a separate step. The experiments were conducted on Whatman model papers, artificially acidified or covered with iron gall ink. The evaluation of the effectiveness was based on tests of breaking length, changes in the DP_visc of cellulose, and pH of the aqueous extracts. Additional information was provided by microscopic examinations (SEM-EDX-SE) and measurements of the optical properties of the tested papers before and after the application of strengthening agents. All the strengthening agents tested increased paper strength—Tylose to the greatest extent, followed by Gelatin, and Klucel G to the least extent. Model papers covered with Klucel G showed good dimensional stability. Gelatin-covered papers showed the greatest changes in optical properties. Full article

(This article belongs to the Section Advanced Nanomaterials and Nanotechnology)

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13 pages, 5136 KB

Open AccessEditor’s ChoiceArticle

Precipitation of β-Mn in the Form of Widmanstätten Side-Plates in the Ferrite Matrix of an Fe–28.6 Mn–10.9 Al Alloy Steel

by Rosemary Chemeli Korir and Wei-Chun Cheng

Materials 2026, 19(1), 133; https://doi.org/10.3390/ma19010133 - 30 Dec 2025

Cited by 1 | Viewed by 848

Abstract

The microstructural evolution and phase stability in Fe–Mn–Al alloys play a decisive role in determining their mechanical performance and potential applications. This study investigates the precipitation behavior and crystallography of the β-Mn phase in an Fe–28.6 Mn–10.9 Al (wt.%) alloy subjected to annealing [...] Read more.

The microstructural evolution and phase stability in Fe–Mn–Al alloys play a decisive role in determining their mechanical performance and potential applications. This study investigates the precipitation behavior and crystallography of the β-Mn phase in an Fe–28.6 Mn–10.9 Al (wt.%) alloy subjected to annealing at 1100 °C, followed by water quenching and subsequent isothermal holding at temperatures between 500 °C and 900 °C for 20 h. Microstructural analysis using X-ray diffraction, optical and electron microscopy revealed a single body-centered cubic (BCC) ferritic matrix above 850 °C and the formation of β-Mn precipitates with Widmanstätten side-plate morphology at lower temperatures. The β-Mn phase was thermally stable between ~500 °C and 850 °C, with the volume fraction increasing with temperature and reaching a maximum near 650 °C. The β-Mn precipitates coarsened progressively with increasing temperature and were found to be richer in Mn than the surrounding Fe-rich BCC matrix. Crystallographic analysis established an orientation relationship (OR) of (

02 \bar{1}

)_β // (100)_α and [

\bar{1} 12

]_β // [012]α, where // denotes nearly parallel alignment, signifying a semi-coherent interface between the two structures. These findings clarify β-Mn precipitation, its interfacial relationship with ferrite, and its thermal stability in high-Mn Fe–Mn–Al alloys, offering guidance for microstructural design in next-generation lightweight steels. Full article

(This article belongs to the Special Issue Alloy Strengthening Mechanisms, Microstructure Control and Performance Optimization (Second Edition))

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24 pages, 6273 KB

Open AccessEditor’s ChoiceArticle

Influence of Post-Processing on S-Phase Formation During Plasma Nitriding of Additively Manufactured Inconel 939

by Piotr Maj, Joanna Radziejewska, Ryszard Diduszko, Michał Marczak, Rafał Nowicki, Podolak-Lejtas Anna, Tomasz Borowski and Ryszard Sitek

Materials 2026, 19(1), 130; https://doi.org/10.3390/ma19010130 - 30 Dec 2025

Viewed by 995

Abstract

Active screen plasma nitriding (ASPN) of additively manufactured nickel-based superalloys represents an understudied surface enhancement pathway. This study presents the first systematic investigation of ASPN applied to additively manufactured Inconel 939 (IN 939), evaluating four distinct post-processing routes combining heat treatment atmospheres (argon [...] Read more.

Active screen plasma nitriding (ASPN) of additively manufactured nickel-based superalloys represents an understudied surface enhancement pathway. This study presents the first systematic investigation of ASPN applied to additively manufactured Inconel 939 (IN 939), evaluating four distinct post-processing routes combining heat treatment atmospheres (argon versus air cooling), vibratory finishing, and lapping under identical nitriding parameters (450 °C, 8 h, 25% N₂ + 75% H₂, 3 hPa). Contrasting nitriding behaviours emerged as a function of the post-processing route: the air-cooled thermal treatment (HT-air-vibr-lap) promotes formation of a thick Al/Cr-rich oxide layer (10–15 µm) that substantially inhibits nitrogen diffusion, resulting in thin and discontinuous nitrided layers. Conversely, the inert atmosphere route (HT-Ar-vibr-lap) circumvents oxide formation, enabling continuous S-phase (expanded austenite, γN) layer development of a 6.4 ± 0.3 µm thickness with exceptional surface hardness (~1200 HV, representing 3–4× enhancement relative to base material). X-ray diffraction confirmed S-phase formation with refined lattice parameter (3.609 Å) and secondary nitride phases (CrN-type and NbN/TaN-type precipitates). The post-processing sequence—particularly heat treatment atmosphere and mechanical finishing methodology—emerged as a critical controlling parameter for S-phase formation efficiency and mechanical properties of nitrided layers in additively manufactured nickel-based superalloys. This work addresses a knowledge gap distinct from the existing literature on conventional Inconel systems, establishing that controlled surface modification through post-processing can achieve the required properties. Full article

(This article belongs to the Special Issue Welding, Joining, and Additive Manufacturing of Metals and Alloys (Third Edition))

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19 pages, 5445 KB

Open AccessEditor’s ChoiceArticle

Analysis of Surface Topography, Dimensional and Geometric Deviations, and Biocidal Properties of 3D Prints Made of Thermoplastic-Based Composites

by Urszula Kmiecik-Sołtysiak, Paweł Szczygieł, Dagmara Michta and Katarzyna Gałczyńska

Materials 2026, 19(1), 129; https://doi.org/10.3390/ma19010129 - 30 Dec 2025

Cited by 4 | Viewed by 1370

Abstract

This study evaluated the properties of two commercial filaments intended for medical and sterile applications: PLACTIVE (Copper 3D, Santiago, Chile) and CPE ANTIBAC (Fiberlogy, Brzezie, Poland). The aim of the research was to compare the dimensional accuracy, repeatability of the fused deposition modeling [...] Read more.

This study evaluated the properties of two commercial filaments intended for medical and sterile applications: PLACTIVE (Copper 3D, Santiago, Chile) and CPE ANTIBAC (Fiberlogy, Brzezie, Poland). The aim of the research was to compare the dimensional accuracy, repeatability of the fused deposition modeling (FDM) 3D printing process, and the antibacterial properties of the samples using standardized procedures. Four types of samples were manufactured: geometrically differentiated specimens for metrological measurements (S1); cylinders with a diameter of 15 mm and a height of 40 mm for assessing process repeatability (S2); rectangular specimens measuring 40 × 40 × 2 mm for surface topography analysis (S3); and rectangular samples measuring 20 × 20 × 2 mm for biocidal property evaluation (S4). The results demonstrated that PLACTIVE samples exhibited higher dimensional conformity with nominal values and lower variability of diameters than CPE ANTIBAC samples, which may be associated with greater process stability. For both materials, the PSm parameter was correlated with layer height only in the 90° printing orientation. Surface topography analysis showed that increasing the layer height from 0.08 mm to 0.20 mm led to a significant rise in Rsm, Ra, and Sa values, indicating deterioration in the reproduction of micro-irregularities and increased spatial differentiation of the surface. For PLACTIVE samples, a tendency toward more convex structures with positive Rsk values and moderate kurtosis (Rku) was observed, suggesting uniform plasticization and stable interlayer bonding, particularly at the 0° orientation. In contrast, CPE ANTIBAC samples (especially those printed at 90°) were characterized by higher Ra and Sa values and negative skewness (Rsk), indicating valley-dominated, sharper surface morphology resulting from different rheological behavior and faster solidification of the material. PLACTIVE samples did not exhibit antibacterial properties against Escherichia coli (E. coli), while for Staphylococcus aureus (S. aureus), the activity was independent of printing direction and layer height. The CPE ANTIBAC material showed antibacterial effects against both tested strains in approximately 50% of the samples. The findings provide insights into the relationships between material type, printing orientation, and process parameters in shaping the dimensional and biocidal properties of FDM filaments. Full article

(This article belongs to the Special Issue Preparation, Properties and Applications of Biocomposites)

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25 pages, 5492 KB

Open AccessEditor’s ChoiceArticle

Assessment of Macroscopic Properties Based on Microhardness Measurements Using the Example of the TiCoCrFeMn High-Entropy Alloy

by Dominika Przygucka, Krzysztof Karczewski, Zbigniew Bojar and Stanisław Jóźwiak

Materials 2026, 19(1), 118; https://doi.org/10.3390/ma19010118 - 29 Dec 2025

Cited by 2 | Viewed by 574

Abstract

In this study, using the newly designed high-entropy alloy TiCoCrFeMn as an example, mathematical models for determining the true hardness from microhardness measurements in the regime dominated by elastic deformation were analyzed. It was found that the PSR model, which accounts for the [...] Read more.

In this study, using the newly designed high-entropy alloy TiCoCrFeMn as an example, mathematical models for determining the true hardness from microhardness measurements in the regime dominated by elastic deformation were analyzed. It was found that the PSR model, which accounts for the variability in the elastic component of the applied indenter load, provides the best agreement with macroscopic hardness measurements. Analysis of the load variation law revealed a correlation between the Young’s modulus and the Meyer coefficient, which formed the basis for developing a model for determining this material parameter from microhardness measurements. The proposed methodology, applicable to small laboratory specimens, was shown to be consistent with the results obtained from crack-length measurements. Full article

(This article belongs to the Special Issue High-Entropy Materials: From Principles to Applications)

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27 pages, 5090 KB

Open AccessEditor’s ChoiceReview

Advanced High-Strength Medium-Manganese Steels as an Alternative to Conventional Forging Steels: A Review

by Aleksandra Kozłowska and Anna Wojtacha

Materials 2026, 19(1), 109; https://doi.org/10.3390/ma19010109 - 28 Dec 2025

Cited by 4 | Viewed by 2000

Abstract

This review highlights conventional forging steels and advanced medium-Mn steels containing retained austenite (RA), emphasizing their potential for industrial forging applications. Modern steels intended for forgings are required to combine strength, ductility, toughness and fatigue resistance with good hardenability and machinability at minimal [...] Read more.

This review highlights conventional forging steels and advanced medium-Mn steels containing retained austenite (RA), emphasizing their potential for industrial forging applications. Modern steels intended for forgings are required to combine strength, ductility, toughness and fatigue resistance with good hardenability and machinability at minimal cost. Medium-Mn multiphase steels fulfill these requirements by the strain-induced martensitic transformation (SIMT) of fine, lath-type RA, which can create a strength–ductility balance. Ferritic–austenitic steels provide high ductility with moderate strength, martensitic–austenitic steels show very high strength at the expense of ductility, and bainitic–austenitic steels achieve intermediate properties. Impact toughness and fatigue resistance are strongly influenced by the morphology of RA. The lath-type RA enhances energy absorption and delays crack initiation, while blocky RA may promote intergranular fracture. Low carbon (0.2–0.3 wt.%) combined with elevated manganese (3–7 wt.%) contents provides superior hardenability and machinability, enabling cost-effective air-hardening of components with various cross-sections. Advanced medium-Mn steels provide a superior mechanical performance and economically attractive solution for modern forgings, exceeding the limitations of conventional steel grades. Full article

(This article belongs to the Special Issue Advanced High-Strength Steels: Processing and Characterization)

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20 pages, 6603 KB

Open AccessEditor’s ChoiceArticle

Effect of Cryogenic Treatment on Low-Density Magnesium Multicomponent Alloys with Exceptional Ductility

by Yu Fang, Michael Johanes and Manoj Gupta

Materials 2026, 19(1), 100; https://doi.org/10.3390/ma19010100 - 27 Dec 2025

Cited by 2 | Viewed by 916

Abstract

There is growing emphasis on lightweight and energy-efficient metallic materials, with multicomponent alloying (MCA) being one strategy to achieve this. This was combined with the inherently lightweight magnesium (Mg) as the base metal. Two Mg-based MCAs, namely Mg-71MCA and Mg-80MCA (Mg-10Li-9Al-6Zn-4Si and Mg-10Li-6Al-2Zn-2Si, [...] Read more.

There is growing emphasis on lightweight and energy-efficient metallic materials, with multicomponent alloying (MCA) being one strategy to achieve this. This was combined with the inherently lightweight magnesium (Mg) as the base metal. Two Mg-based MCAs, namely Mg-71MCA and Mg-80MCA (Mg-10Li-9Al-6Zn-4Si and Mg-10Li-6Al-2Zn-2Si, respectively, wt.%), with density in the range of 1.55–1.632 g/cc akin to plastics were synthesized via the Disintegrated Melt Deposition method in this work. The effects of cryogenic treatment (CT) at –20 °C, 80 °C, and –196 °C (LN) on the physical, microstructural, thermal, and mechanical properties were systematically evaluated. CT resulted in densification, significant grain refinement (up to a 27.9% reduction in grain diameter after LN treatment), alterations in crystallographic texture, and notable changes to secondary phases—namely, an increased precipitate area fraction. These led to enhanced mechanical performance such as damping capacity, microhardness, and compressive response (most apparent for Mg-71MCA with 12.1%, 6.7%, and 1.6% increase in yield strength, ultimate compressive strength, and energy absorbed, respectively, after RF20 treatment), coupled with exceptional ductility (>80% strain without fracture), which is superior to pure Mg and commercial Mg alloys. Overall, this work showcases the potential of MCAs compared to existing conventional lightweight materials, as well as the property-enhancing/tailoring effects brought upon by different CT temperatures. This highlights the multi-faceted nature of material designs where compositional control and judicious processing parameter selection need to be both leveraged to optimize final properties, and serves as a baseline for further lightweight MCA development to meet future needs. Full article

(This article belongs to the Special Issue Advances in Al/Mg/Cu Alloys and Their Composites: Welding, Additive Manufacturing, Heterogeneous Microstructures, and Mechanical Properties)

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13 pages, 3595 KB

Open AccessEditor’s ChoiceArticle

Study on the Application of Machine Learning of Melt Pool Geometries in Silicon Steel Fabricated by Powder Bed Fusion

by Ho Sung Jang, Sujeong Kim, Jong Bae Jeon, Donghwi Kim, Yoon Suk Choi and Sunmi Shin

Materials 2026, 19(1), 68; https://doi.org/10.3390/ma19010068 - 24 Dec 2025

Cited by 1 | Viewed by 1460

Abstract

In this study, regression-based machine learning models were developed to predict the melt pool width and depth formed during the Laser Powder Bed Fusion (LPBF) process for Fe-3.4Si and Fe-6Si alloys. Based on experimentally obtained melt pool width and depth data, a total [...] Read more.

In this study, regression-based machine learning models were developed to predict the melt pool width and depth formed during the Laser Powder Bed Fusion (LPBF) process for Fe-3.4Si and Fe-6Si alloys. Based on experimentally obtained melt pool width and depth data, a total of 11 regression models were trained and evaluated, and hyperparameters were optimized via Bayesian optimization. Key process parameters were identified through data preprocessing and feature engineering, and SHAP analysis confirmed that the input energy had the strongest influence on both melt pool width and depth. The comparison of prediction performance revealed that the support vector regressor with a linear kernel (SVR_lin) exhibited the best performance for predicting melt pool width, while the multilayer perceptron (MLP) model achieved the best results for predicting melt pool depth. Based on these trained models, a power–velocity (P-V) process map was constructed, incorporating boundary conditions such as the overlap ratio and the melt pool morphology. The optimal input energy range was derived as 0.45 to 0.60 J/mm, ensuring stable melt pool formation. Specimens manufactured under the derived conditions were analyzed using 3D X-ray CT, revealing porosity levels ranging from 0.29% to 2.89%. In particular, the lowest porosity was observed under conduction mode conditions when the melt pool depth was approximately 1.0 to 1.5 times the layer thickness. Conversely, porosity tended to increase in the transition mode and lack of fusion regions, consistent with the model predictions. Therefore, this study demonstrated that a machine learning-based regression model can reliably predict melt pool characteristics in the LPBF process of Fe-Si alloys, contributing to the development of process maps and optimization strategies. Full article

(This article belongs to the Special Issue Intelligent Processing Technology of Materials)

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11 pages, 4932 KB

Open AccessEditor’s ChoiceArticle

Enhanced Electron–Phonon Coupling of Superconductivity in Indium-Doped Topological Crystalline Insulator SnTe

by Kwan-Young Lee, Gareoung Kim, Jae Hyun Yun, Jin Hee Kim and Jong-Soo Rhyee

Materials 2026, 19(1), 73; https://doi.org/10.3390/ma19010073 - 24 Dec 2025

Cited by 1 | Viewed by 1059

Abstract

Indium-doped SnTe (Sn_1−xIn_xTe) provides a model platform for exploring the emergence of superconductivity within a topological crystalline insulator. Here, we present a systematic investigation of the structural, transport, and thermodynamic properties of high-quality single crystals with 0.0 ≤ x [...] Read more.

Indium-doped SnTe (Sn_1−xIn_xTe) provides a model platform for exploring the emergence of superconductivity within a topological crystalline insulator. Here, we present a systematic investigation of the structural, transport, and thermodynamic properties of high-quality single crystals with 0.0 ≤ x ≤ 0.5. All compositions up to x = 0.4 form a single-phase cubic structure, enabling a controlled study of the superconducting state. Electrical resistivity and specific heat measurements reveal a bulk, fully gapped s-wave superconducting phase whose transition temperature increases monotonically with In concentration, reaching Tc ≈ 4.7 K at x = 0.5. Analysis of the electronic specific heat and McMillan formalism shows that the electron–phonon coupling constant λ_el_-_ph systematically increases with doping, while the Debye temperature systematically decreases, resulting in the lattice softening. This behavior, together with the observed evolution of the normal-state resistivity exponent from Fermi-liquid (n ≈ 2.04) toward non-Fermi-liquid values (n ≈ 1.72), demonstrates a clear crossover from weak to strong interaction with increasing In content. These results establish Sn_1−xIn_xTe as a tunable superconducting system in which coupling strength can be continuously controlled, offering a promising platform for future studies on the interplay between phonon-mediated superconductivity and crystalline topological band structure. Full article

(This article belongs to the Special Issue Advances in Superconductor Materials: Preparation and Characterization)

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14 pages, 3045 KB

Open AccessEditor’s ChoiceArticle

Effectiveness of Ozone Treatment, Ultrasonic Treatment, and Ultraviolet Irradiation in Removing Candida albicans Adhered to Acrylic Resins Fabricated by Different Manufacturing Methods

by Chihiro Kaneko, Tomofumi Sawada, Taichi Ishikawa, Toshitaka Miura, Takuya Kobayashi and Shinji Takemoto

Materials 2026, 19(1), 53; https://doi.org/10.3390/ma19010053 - 23 Dec 2025

Viewed by 1392

Abstract

Acrylic resins are commonly used for denture bases due to ease of molding but are prone to water absorption and microbial contamination. This study aimed to evaluate the effects of ozonated water immersion (OZ), ultrasonic cleaning (US), and ultraviolet (UV) irradiation on the [...] Read more.

Acrylic resins are commonly used for denture bases due to ease of molding but are prone to water absorption and microbial contamination. This study aimed to evaluate the effects of ozonated water immersion (OZ), ultrasonic cleaning (US), and ultraviolet (UV) irradiation on the removal of Candida albicans from acrylic resins produced by heat curing and additive manufacturing. The resin specimens were then subjected to treatment with OZ, US, UV irradiation, and commercial denture cleansers. Following treatment, the number of viable C. albicans cells was quantified and statistically analyzed (α = 0.05), morphology was observed under a scanning electron microscope (SEM) and fluorescence imaging. OZ, US, and UV irradiation significantly reduced the viable C. albicans count. Notably, the combination of the three treatments achieved a reduction exceeding 99.9% of viable cells. Although SEM revealed that C. albicans remained on the specimens, fluorescence imaging demonstrated a progressive decrease in viable cells and an increase in dead cells with each treatment, with the greatest effect observed when the three treatments were combined. The difference of removal behaviors of C. albicans among fabrication methods was not observed, comparable to denture cleaners. The combined application of all three treatments was the most effective strategy for microbial removal. Full article

(This article belongs to the Special Issue Advances and Applications of 3D Printing and Additive Manufacturing)

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14 pages, 1892 KB

Open AccessEditor’s ChoiceArticle

In Situ Dose Measurements in Brachytherapy Using Scintillation Detectors Based on the Al₂O₃:C, Al₂O₃:C,Mg, and GAGG:Ce Crystals

by Sandra Witkiewicz-Lukaszek, Janusz Winiecki, Bogna Sobiech, Mark Akselrod and Yuriy Zorenko

Materials 2026, 19(1), 45; https://doi.org/10.3390/ma19010045 - 22 Dec 2025

Cited by 2 | Viewed by 1229

Abstract

Currently, the use of scintillation crystals connected via optical fiber to a luminescence spectrometer (so-called fiber-optic dosimeters) offers a promising approach for real-time dosimetric measurements during brachytherapy treatments with γ-ray sources. This study aims to evaluate the applicability of fiber-optic dosimeters for in [...] Read more.

Currently, the use of scintillation crystals connected via optical fiber to a luminescence spectrometer (so-called fiber-optic dosimeters) offers a promising approach for real-time dosimetric measurements during brachytherapy treatments with γ-ray sources. This study aims to evaluate the applicability of fiber-optic dosimeters for in situ dose measurements during brachytherapy procedures, using Al₂O₃:C and Al₂O₃:C,Mg crystals, which have near-tissue density and effective atomic number (ρ = 3.99 g/cm³, Z_eff = 10.8), as well as heavy GAGG:Ce scintillation crystals (ρ = 6.63 g/cm³, Z_eff = 54.4). Radiation dose delivery was assessed through measurements of the resulting radioluminescence of the aforementioned scintillation crystals, connected via long optical fibers and recorded with highly sensitive, compact luminescence spectrometers. Measurements were performed in a dedicated phantom under clinical conditions at the Oncology Center in Bydgoszcz, Poland. The dosimeters were evaluated for in situ dose monitoring within the 0.5–8 Gy range during brachytherapy procedures using a ¹⁹²Ir (392 keV) source. The results showed a clear linear relationship between the delivered radiation dose and the scintillation output measured by the fiber-optic detector. The Gd₃Al_2.5Ga_2.5O₁₂:Ce crystal detector exhibited excellent linearity, while the Al₂O₃:C and Al₂O₃:C,Mg crystal detectors also showed a nearly linear dose–response relationship. Full article

(This article belongs to the Special Issue Advanced Scintillator and Detector Materials for Radiation Physics and Nuclear Medicine)

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33 pages, 2704 KB

Open AccessEditor’s ChoiceReview

Why Does Mucoadhesion Matter? Mucoadhesive Drug Delivery Systems with Antifungal Activity in the Local Treatment of Oral Cavity Candidiasis

by Katarzyna Olechno, Julia Higuchi and Katarzyna Winnicka

Materials 2026, 19(1), 33; https://doi.org/10.3390/ma19010033 - 21 Dec 2025

Cited by 7 | Viewed by 2230

Abstract

Disorders in the oral cavity caused by pathogenic fungi pose a significant clinical challenge, particularly in immunocompromised patients, as well as those undergoing oncological therapy or antibiotic treatment. A practical therapeutic approach involves the topical application of mucoadhesive drug dosage forms. However, only [...] Read more.

Disorders in the oral cavity caused by pathogenic fungi pose a significant clinical challenge, particularly in immunocompromised patients, as well as those undergoing oncological therapy or antibiotic treatment. A practical therapeutic approach involves the topical application of mucoadhesive drug dosage forms. However, only a limited number of such preparations are available on the pharmaceutical market. Mucoadhesive systems are especially advantageous, as they ensure prolonged retention and adequate concentrations of the active substances at the site of infection. Localized drug delivery enhances therapeutic efficacy compared to systemic administration, enabling lower drug doses, and consequently reducing the risk of side effects. Moreover, many fungal conditions require long-term treatment, which may be optimized by the use of mucoadhesive systems, improving patient compliance. Considering the issue of limited adhesion of conventional drug dosage forms and the moist environment in the oral cavity, providing optimal mucoadhesive properties is a key aspect. This article presents a comprehensive overview of the significance of treating oral candidiasis using mucoadhesive drug dosage forms, the mechanisms and advantages of mucoadhesion (including relevant polymers), and, most importantly, recent scientific reports on the development and quality assessment of mucoadhesive drug delivery systems for the management of oral fungal diseases. Full article

(This article belongs to the Section Biomaterials)

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20 pages, 6044 KB

Open AccessEditor’s ChoiceArticle

Photocatalytic Decomposition of Carmoisine and Crystal Violet by Ho-Doped TiO₂ Sol-Gel Powders

by Nina Kaneva, Stefani Petrova and Albena Bachvarova-Nedelcheva

Materials 2026, 19(1), 17; https://doi.org/10.3390/ma19010017 - 20 Dec 2025

Cited by 2 | Viewed by 1209

Abstract

This study explores the sol–gel synthesis, structural characterization, and photocatalytic performance of Ho³⁺-doped TiO₂ nanopowders at two dopant levels (0.5 and 2 mol%). Transparent, homogeneous gels were prepared using titanium (IV) butoxide and holmium (III) nitrate pentahydrate in ethanol, followed [...] Read more.

This study explores the sol–gel synthesis, structural characterization, and photocatalytic performance of Ho³⁺-doped TiO₂ nanopowders at two dopant levels (0.5 and 2 mol%). Transparent, homogeneous gels were prepared using titanium (IV) butoxide and holmium (III) nitrate pentahydrate in ethanol, followed by drying and optional annealing at 500 °C. X-ray diffraction confirmed anatase TiO₂ as the dominant crystalline phase, with Ho incorporation suppressing crystal growth and yielding smaller crystallite sizes than undoped TiO₂. FT-IR and UV-Vis spectroscopy verified complete hydrolysis–condensation during gel formation, while diffuse reflectance spectra revealed a red-shifted absorption edge, indicating reduced band gaps. SEM analysis showed nanoscale particles with agglomeration, which intensified after annealing. Photocatalytic activity was tested under UV irradiation using Crystal Violet (anionic dye) and Carmoisine (cationic dye). Annealed Ho-doped powders exhibited markedly higher degradation rates, with the 2 mol% sample achieving the greatest efficiency, particularly against Crystal Violet. These findings demonstrate that Ho³⁺ doping enhances TiO₂’s UV-driven photocatalytic activity by tailoring its structural and optical properties. Full article

(This article belongs to the Special Issue Photocatalysis for a Green Future: Breaking Barriers in Energy, Environment, and Healthcare)

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16 pages, 9578 KB

Open AccessEditor’s ChoiceArticle

Effect of Molybdenum on Microstructural Evolution and High Cycle Fatigue Properties of Ti-xMo-2Fe Alloys

by HyoWoon Hwang and Dong-Geun Lee

Materials 2026, 19(1), 10; https://doi.org/10.3390/ma19010010 - 19 Dec 2025

Cited by 1 | Viewed by 1286

Abstract

Ti-xMo-2Fe alloys with high specific strength were designed by adding Mo and Fe as β-stabilizing elements. The influence of cold swaging on the martensitic transformations in Ti-xMo-2Fe (x = 3.4, 5, 9.2 wt.%) alloys was investigated. In these alloys, appropriate chemical compositions promote [...] Read more.

Ti-xMo-2Fe alloys with high specific strength were designed by adding Mo and Fe as β-stabilizing elements. The influence of cold swaging on the martensitic transformations in Ti-xMo-2Fe (x = 3.4, 5, 9.2 wt.%) alloys was investigated. In these alloys, appropriate chemical compositions promote a stress-induced phase transformation from the β phase to orthorhombic α″ martensite, which improves elongation while maintaining high strength. As the Mo content increases from 3.4 to 5 wt.%, the amount of β-stabilizing elements increases and the β stability is enhanced, thereby altering the phase transformation mechanism. In the Ti-9.2Mo-2Fe alloy, both α″ martensite and a very hard ω phase were identified by X-ray diffraction and transmission electron microscopy. The hard and brittle ω phase causes premature brittle fracture prior to macroscopic yielding. Among the investigated alloys, the Ti-5Mo-2Fe alloy exhibits the best overall combination of high tensile strength, elongation to failure, and high fatigue strength. Full article

(This article belongs to the Special Issue Welding, Joining, and Additive Manufacturing of Metals and Alloys (Third Edition))

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30 pages, 13137 KB

Open AccessEditor’s ChoiceArticle

Effect of Ni Addition on the Solidification of Liquid Al and Solid Cu Diffusion Couples

by Vigneshwar Hari, Stuart D. McDonald, Xin Fu Tan and Kazuhiro Nogita

Materials 2025, 18(24), 5689; https://doi.org/10.3390/ma18245689 - 18 Dec 2025

Cited by 1 | Viewed by 1239

Abstract

Al-Ni alloys have a unique set of properties including high conductivity, high fluidity, good thermal stability, and reasonable strength. These properties are also needed for effective braze fillers, a novel application for Al-Ni alloys. A Cu substrate was reacted with pure liquid Al, [...] Read more.

Al-Ni alloys have a unique set of properties including high conductivity, high fluidity, good thermal stability, and reasonable strength. These properties are also needed for effective braze fillers, a novel application for Al-Ni alloys. A Cu substrate was reacted with pure liquid Al, and the resulting microstructure upon solidification was observed and analysed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). This diffusion couple was compared with the diffusion couple between liquid eutectic Al-3at.%Ni and a Cu substrate. Several phases unique to the solidified liquid in the Al-Ni/Cu diffusion couple were observed, such as Al₇Cu₄Ni (τ), Al₃(Cu, Ni)₂, and Al₃Ni. These microstructures were compared with a mathematical model based on Fick’s second law, as well as calculation of phase diagram (CALPHAD) modelling. The approximate calculated concentration profile of Cu in the liquid phase was validated against the microstructural observations and proved effective to explain the observed microstructural features. Liquid Al-3at.%Ni was found to limit the growth of the brittle Al₂Cu (θ) phase during solidification by limiting Cu solubility in the liquid phase, which would be beneficial for use in dissimilar joints between Al and Cu. Full article

(This article belongs to the Section Metals and Alloys)

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14 pages, 11633 KB

Open AccessEditor’s ChoiceArticle

Molybdenum Nitride and Oxide Layers Grown on Mo Foil for Supercapacitors

by Dong Hyun Lim and Young-Il Kim

Materials 2025, 18(24), 5649; https://doi.org/10.3390/ma18245649 - 16 Dec 2025

Cited by 1 | Viewed by 972

Abstract

In this study, thin molybdenum nitride (MoN_x) layers were directly synthesized on molybdenum foil via thermal treatment under an NH₃ atmosphere, and their phase evolution, structural characteristics, and electrochemical performance were investigated. The thickness and morphology of the MoN_x [...] Read more.

In this study, thin molybdenum nitride (MoN_x) layers were directly synthesized on molybdenum foil via thermal treatment under an NH₃ atmosphere, and their phase evolution, structural characteristics, and electrochemical performance were investigated. The thickness and morphology of the MoN_x layers were controlled by varying ammonolysis time and temperature, while subsequent annealing in N₂ converted the nitride layer into MoO₂. Meanwhile, oxidation in air yielded crystalline MoO₃ layers. X-ray diffraction and X-ray photoelectron spectroscopy confirmed progressive oxidation of molybdenum, with Mo 3d binding energies increasing in the sequence of Mo < MoN_x < MoO₂ < MoO₃, consistent with their nominal oxidation states. Electrochemical characterization revealed that both MoN_x/Mo and MoO₂/Mo electrodes exhibit notable pseudocapacitive behavior in 0.5 M H₂SO₄ electrolyte, with areal specific capacitances reaching up to 520 mF cm⁻² at 10 mV s⁻¹. Increasing layer thickness led to enhanced capacitance, likely due to an increase in the electrochemically accessible surface area and the extension of ion diffusion pathways. MoO₂-coated samples showed stronger faradaic contribution and superior rate capability compared to MoN_x counterparts, along with a gradual shift from predominantly electric double-layer capacitance toward hybrid pseudocapacitive charge storage mechanisms. Full article

(This article belongs to the Special Issue Sustainable Functional Materials for Energy and Environmental Applications)

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19 pages, 7887 KB

Open AccessEditor’s ChoiceArticle

Improving the Surface Quality of Network Microstructure Titanium Matrix Composites Using Electrochemical Milling Following EDM

by Yizhou Hu, Leheng Zhang, Sirui Gong and Zhenlong Wang

Materials 2025, 18(24), 5628; https://doi.org/10.3390/ma18245628 - 15 Dec 2025

Cited by 4 | Viewed by 763

Abstract

Network microstructure titanium matrix composites (NMTMCs) possess excellent performance and are promising for aerospace applications, yet their microstructural heterogeneity poses substantial challenges to achieving high-quality micro-machined surfaces. The aim of this study is to evaluate electrochemical machining (ECM) as a post-processing method for [...] Read more.

Network microstructure titanium matrix composites (NMTMCs) possess excellent performance and are promising for aerospace applications, yet their microstructural heterogeneity poses substantial challenges to achieving high-quality micro-machined surfaces. The aim of this study is to evaluate electrochemical machining (ECM) as a post-processing method for improving the surface quality of NMTMCs after electrical discharge machining (EDM). This study systematically examines the effects of electrolyte concentration, machining voltage, and pulse frequency on surface roughness. Electrochemical measurements in NaCl and NaNO₃ revealed that standalone electrochemical machining causes severe selective corrosion due to the large dissolution rate mismatch between TiBw reinforcements and the Ti-6Al-4V matrix, making it unsuitable for direct finishing. Accordingly, ECM was applied to EDM-prepared surfaces, and under optimized conditions (10 wt.% NaCl, 4.5 V, 200 kHz), ECM effectively mitigates the protrusions at the edges of discharge pits caused by the EDM process. Surface roughness (Sa) is significantly reduced from 0.90 μm to 0.45 μm, and the surface morphology becomes more uniform. These results demonstrate that ECM is a viable post-EDM finishing strategy for achieving high-quality micro-machining of NMTMCs. Full article

(This article belongs to the Special Issue Material Surface Topography Measurement, Analysis and Characterization (2nd Edition))

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16 pages, 1905 KB

Open AccessEditor’s ChoiceArticle

Modifying Polylactide with Powdered Cork Filler

by Mariusz Fabijański, Jacek Garbarski and Zbigniew Szymaniak

Materials 2025, 18(24), 5606; https://doi.org/10.3390/ma18245606 - 13 Dec 2025

Cited by 5 | Viewed by 837

Abstract

The paper presents the results of experimental testing of a PLA-based composite, modified with powdered cork and a compatibilizer. The purpose of applying these additives was to evaluate their influence upon the physical, structural and functional properties of the obtained material. Specimens with [...] Read more.

The paper presents the results of experimental testing of a PLA-based composite, modified with powdered cork and a compatibilizer. The purpose of applying these additives was to evaluate their influence upon the physical, structural and functional properties of the obtained material. Specimens with various cork and compatibilizer contents were analyzed to evaluate the synergic interaction between the polymer base and the filler. The tests of the mechanical properties, water absorption and FTIR analysis were carried out. The results confirmed that the cork filler improved the PLA-based composite both in terms of the utility and ecological aspects. Despite a certain mechanical deterioration, the properties remain fully acceptable for packaging applications. Also, the improvement of hardness at higher cork content was observed, which points to effective phase interaction and a good adherence of the components. The FTIR spectroscopy confirmed chemical stability of the base and the lack of unwanted degradation reactions. The obtained composite is an innovative, biodegradable polymer material that utilizes natural waste in a way which is both economic and environmentally friendly. The obtained results point to a high application potential of this kind of composite, mainly in the packaging industry and in the field of ecological utility materials. Full article

(This article belongs to the Section Polymeric Materials)

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20 pages, 4134 KB

Open AccessEditor’s ChoiceArticle

Effect of Hyaluronic Acid Content on Functional Properties, Antioxidant Activity, and In Vitro Digestion of Food-Grade Furcellaran Hydrogels and Emulgels

by Anna Stępień, Lesław Juszczak, Aneta Koronowicz, Aleksandra Such, Grzegorz Kowalski, Beata Synkiewicz-Musialska, Piotr Zachariasz and Ewelina Jamróz

Materials 2025, 18(24), 5581; https://doi.org/10.3390/ma18245581 - 12 Dec 2025

Cited by 4 | Viewed by 946

Abstract

Gel biocomposites, with their wide range of properties, are increasingly popular in many industries, while hyaluronic acid (HA), due to its unique water-binding mechanisms, has a high application potential in these types of materials. Furcellaran-based composite hydrogels and emulsion gels with different HA [...] Read more.

Gel biocomposites, with their wide range of properties, are increasingly popular in many industries, while hyaluronic acid (HA), due to its unique water-binding mechanisms, has a high application potential in these types of materials. Furcellaran-based composite hydrogels and emulsion gels with different HA additions were produced and the effect of HA concentration on physical, color, textural, mechanical, rheological, and antioxidant properties was evaluated. A polysaccharide network was observed, which—according to Fourier transform infrared spectroscopy(FTIR) and X-ray diffraction (XRD) data—is stabilized by hydrogen bonding. Emulsion gels revealed denser structures. Small deformation tests confirmed elastic–solid type of all investigated gels. The opposite effect of HA on the swelling behavior of hydro- and emulgels was observed. Increasing hyaluronic acid content resulted in elasticity enhancement and hardness reduction. Antioxidant potential of composites significantly increased with HA concentration. The obtained materials have potential applications as plat-based delivery systems for hydrophilic and lipophilic bioactive components. Full article

(This article belongs to the Special Issue Functional Hydrogels: Design, Properties and Applications (Second Edition))

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27 pages, 8431 KB

Open AccessEditor’s ChoiceArticle

A Comparison Between the Growth of Naturally Occurring Three-Dimensional Cracks in Scalmalloy^® and Pre-Corroded 7085-T7452 and Its Implications for Additively Manufactured Limited-Life Replacement Parts

by Daren Peng, Shareen S. L. Chan, Ben Main, Andrew S. M. Ang, Nam Phan, Michael R. Brindza and Rhys Jones

Materials 2025, 18(24), 5586; https://doi.org/10.3390/ma18245586 - 12 Dec 2025

Cited by 2 | Viewed by 1073

Abstract

This paper is the first to reveal that the conventionally built aluminium alloy (AA) 7085-T7452 has mechanical properties, viz: a yield stress, ultimate strength, and an elongation to failure, that are similar to that of laser powder bed fusion (LPBF) built Scalmalloy^® [...] Read more.

This paper is the first to reveal that the conventionally built aluminium alloy (AA) 7085-T7452 has mechanical properties, viz: a yield stress, ultimate strength, and an elongation to failure, that are similar to that of laser powder bed fusion (LPBF) built Scalmalloy^®. Following this observation, the growth of cracks that nucleated from corrosion pits in AA7085-T7452 specimens that had been exposed to a 5 wt% NaCl salt fog environment at 35 °C according to ASTM B117-19 standard for fourteen days is then studied. The specimen geometries were chosen to be identical to those associated with a similar study on Boeing Space, Intelligence, and Weapon Systems (BSI&WS) LPBF built Scalmalloy^®. This level of prior exposure led to pits in AA7085-T7452 that were approximately 0.5 mm deep with a surface width/diameter of up to approximately 1.5 mm. These pit sizes are broadly consistent with those leading to fatigue crack growth (FCG) in AA 7050-T7451 structural parts on the RAAF F/A-18 Classic Hornet fleet operating in a highly corrosive environment. Fatigue tests on these AA7085-T7452 specimens, under the same spectrum as used in the BSI&WS LPBF Scalmalloy^® study, reveals that AA7085-T7452 and Scalmalloy^® have similar crack growth histories. This, in turn, leads to the discovery that the growth of naturally occurring three-dimensional (3D) cracks in AA 7085-T7452 could be predicted using the crack growth equation developed for BSI&WS LPBF Scalmalloy^®, albeit with allowance made for their different fracture toughness’s. These findings suggest that Scalmalloy^® may be suitable for printing parts for both current and future attritable aircraft. Full article

(This article belongs to the Section Manufacturing Processes and Systems)

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14 pages, 4122 KB

Open AccessEditor’s ChoiceArticle

Floatable Syntactic Magnesium Foam as a Marangoni-Induced Propulsion Microboat

by Gyorgy Thalmaier, Niculina Argentina Sechel and Ioan Vida-Simiti

Materials 2025, 18(24), 5588; https://doi.org/10.3390/ma18245588 - 12 Dec 2025

Cited by 1 | Viewed by 652

Abstract

This study reports the successful fabrication and application of floatable syntactic foams derived from fine magnesium powder (<45 µm) utilizing expanded perlite (0.25 g/cm³, 0.2–0.4 mm) as the pore former. Sample disks with densities as low as 0.9 g/cm³ were [...] Read more.

This study reports the successful fabrication and application of floatable syntactic foams derived from fine magnesium powder (<45 µm) utilizing expanded perlite (0.25 g/cm³, 0.2–0.4 mm) as the pore former. Sample disks with densities as low as 0.9 g/cm³ were produced via the classical press and sinter process. To ensure reasonable mechanical properties, the specimens were formed under a pressure of 200 MPa in a hardened steel die, followed by high-vacuum sintering (~3 × 10⁻⁶ torr) at 640 °C for 1 h. The resulting foams exhibited sufficient mechanical strength to allow for precision machining into a microboat. We demonstrated their potential use as a Marangoni-induced microswimmer. Spontaneous locomotion was observed when ethanol was used as a propellant, which generates a surface tension gradient between the upper and rear parts of the swimmer. The microboats achieved propulsion speeds of approximately 160 mm/s when propelled by a 95% ethanol + 5% ink mixture. Using a small volume (~4 µL) of the alcohol mixture, the swimmer could cover distances exceeding 350 mm. Full article

(This article belongs to the Special Issue Obtaining and Characterization of New Materials (5th Edition))

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17 pages, 16918 KB

Open AccessEditor’s ChoiceArticle

Key Factors Influencing the Mechanical Properties of Binodal Decomposed Metallic Glass Composites

by Yongwei Wang, Guangping Zheng and Mo Li

Materials 2025, 18(24), 5593; https://doi.org/10.3390/ma18245593 - 12 Dec 2025

Viewed by 772

Abstract

Structural heterogeneity plays a crucial role in enhancing the mechanical properties of metallic glasses (MGs) by impeding the propagation of shear bands (SBs). Metallic glass matrix composites (MGCs) consisting of reinforcements are of great interest as they enhance the mechanical performance of brittle [...] Read more.

Structural heterogeneity plays a crucial role in enhancing the mechanical properties of metallic glasses (MGs) by impeding the propagation of shear bands (SBs). Metallic glass matrix composites (MGCs) consisting of reinforcements are of great interest as they enhance the mechanical performance of brittle MGs. However, managing the dispersity of hetero-phases within the glassy matrix presents technical challenges due to surface tension and thermal property incompatibility. Binodal phase separation is an effective approach for fabricating MGCs with uniformly dispersed glassy droplets or particles. The species of matrix and characteristics of particle reinforcements significantly influence mechanical properties. This study theoretically examines how the fraction, size, and variety of particle reinforcements influence performance using finite element models based on free volume theory. The synergistic mechanisms for performance tuning involve stress fields generated by particle reinforcements that modify the nucleation and propagation of SBs in the matrix. Additionally, the size effect of particles depends on their interaction with SBs. This comprehensive understanding could substantially enhance the design and optimization for MGCs. Full article

(This article belongs to the Special Issue Next-Generation Alloys: Nanostructured Metals, Complex Steels, and Multi-Component Systems)

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18 pages, 10014 KB

Open AccessEditor’s ChoiceArticle

Directional Coupling of Surface Plasmon Polaritons at Exceptional Points in the Visible Spectrum

by Amer Abdulghani, Salah Abdo, Khalil As’ham, Ambali Alade Odebowale, Andrey E. Miroshnichenko and Haroldo T. Hattori

Materials 2025, 18(24), 5595; https://doi.org/10.3390/ma18245595 - 12 Dec 2025

Cited by 1 | Viewed by 1030

Abstract

Robust control over the coupling and propagation of surface plasmon polaritons (SPPs) is essential for advancing various plasmonic applications. Traditional planar structures, commonly used to design SPP directional couplers, face limitations such as low extinction ratios and design complexities. These issues frequently hinder [...] Read more.

Robust control over the coupling and propagation of surface plasmon polaritons (SPPs) is essential for advancing various plasmonic applications. Traditional planar structures, commonly used to design SPP directional couplers, face limitations such as low extinction ratios and design complexities. These issues frequently hinder the dense integration and miniaturisation of photonic systems. Recently, exceptional points (EPs)—unique degeneracies within the parameter space of non-Hermitian systems—have garnered significant attention for enabling a range of counterintuitive phenomena in non-conservative photonic systems, including the non-trivial control of light propagation. In this work, we develop a rigorous temporal coupled-mode theory (TCMT) description of a non-Hermitian metagrating composed of alternating silicon–germanium nanostrips and use it to explore the unidirectional excitation of SPPs at EPs in the visible spectrum. Within this framework, EPs, typically associated with the coalescence of eigenvalues and eigenstates, are leveraged to manipulate light propagation in nonconservative photonic systems, facilitating the refined control of SPPs. By spatially modulating the permittivity profile at a dielectric–metal interface, we induce a passive parity–time (

PT

)-symmetry, which allows for refined tuning of the SPPs’ directional propagation by optimising the structure to operate at EPs. At these EPs, a unidirectional excitation of SPPs with a directional intensity extinction ratio as high as 40 dB between the left and right excited SPP modes can be reached, with potential applications in integrated optical circuits, visible communication technologies, and optical routing, where robust and flexible control of light at the nanoscale is crucial. Full article

(This article belongs to the Section Optical and Photonic Materials)

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13 pages, 4637 KB

Open AccessEditor’s ChoiceArticle

Rapid Stress Relief of Ti-6Al-4V Titanium Alloy by Electropulsing Treatment

by Aprilia Aprilia, Jin Lee Tan, Zixuan Ling, Vincent Gill, Paul Williams, Martyn A. Jones and Wei Zhou

Materials 2025, 18(24), 5555; https://doi.org/10.3390/ma18245555 - 11 Dec 2025

Cited by 2 | Viewed by 1681

Abstract

This study investigates the effectiveness and underlying mechanisms of electropulsing treatment (EPT) for rapid stress relief of Ti-6Al-4V titanium alloy. Stress relief is an essential step in manufacturing processes to ensure long component lifespan. Residual stress accumulation within a component is often undesirable, [...] Read more.

This study investigates the effectiveness and underlying mechanisms of electropulsing treatment (EPT) for rapid stress relief of Ti-6Al-4V titanium alloy. Stress relief is an essential step in manufacturing processes to ensure long component lifespan. Residual stress accumulation within a component is often undesirable, as it may lead to premature failures. Currently, the stress relief of titanium alloys is typically carried out using an annealing heat-treatment process in a vacuum furnace. However, this method is time-consuming, usually requiring several hours. In this paper, an alternative fast stress relief method by EPT was investigated. A controllable pulsing treatment using alternating high density pulsing current with short pulse width was carried out. Results showed that EPT is effective in relieving residual stress in Ti-6Al-4V alloy. Up to 90% of the surface residual stresses induced by shot peening were successfully relieved by EPT with a treatment duration of only 114 ms. Reductions of low-angle grain boundaries (2–10°), local misorientation, and deformed grains were observed, while no significant grain growth or phase transformation was found. The stress-relief mechanism of EPT is attributed to the combined effects of dislocation movement driven by electron wind force (EWF), dislocation creep at elevated temperatures, and dislocation glide due to local yielding of residual stress under high-temperature conditions. The temperature rise during EPT was identified as a significant factor enabling stress relaxation. Full article

(This article belongs to the Special Issue Microstructure, Mechanical and Corrosion Properties of Metals, Alloys, and Composite Materials)

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26 pages, 18739 KB

Open AccessEditor’s ChoiceArticle

ZnO Thin Films as Promising Corrosion Protection on Mg-Based Alloys

by Aneta Kania, Magdalena M. Szindler, Marek Szindler, Zbigniew Brytan, Monika Kciuk, Wojciech Pakieła, Łukasz Reimann and Paweł M. Nuckowski

Materials 2025, 18(24), 5568; https://doi.org/10.3390/ma18245568 - 11 Dec 2025

Cited by 2 | Viewed by 807

Abstract

The present study examined the microstructure and corrosion characteristics of MgCa4Zn1Gd1 and MgCa2Zn1Gd3 alloys that were coated with ZnO thin films, which were deposited by atomic layer deposition (ALD). Coatings of different thicknesses (42.5, 95.4 and 133.7 nm for 500, 1000, and 1500 [...] Read more.

The present study examined the microstructure and corrosion characteristics of MgCa4Zn1Gd1 and MgCa2Zn1Gd3 alloys that were coated with ZnO thin films, which were deposited by atomic layer deposition (ALD). Coatings of different thicknesses (42.5, 95.4 and 133.7 nm for 500, 1000, and 1500 cycles, respectively) were characterized using X-ray diffraction (XRD), Raman spectroscopy, SEM/EDS, AFM (atomic force microscope), and FTIR (Fourier transform infrared spectroscopy). XRD and Raman analyses were conducted to verify the formation of crystalline zinc oxide (ZnO) with a homogeneous granular morphology. Surface roughness decreased with increasing coating thickness, reaching the lowest values for the 1500-cycle ZnO layer on MgCa2Zn1Gd3 (R_a = 7.65 nm, R_s = 9.8 nm). Potentiodynamic and immersion tests in Ringer solution at 37 °C revealed improved corrosion resistance for thicker coatings, with the lowest hydrogen evolution (20.89 mL·cm⁻²) observed for MgCa2Zn1Gd3 coated after 1500 cycles. Analysis of corrosion products by FTIR identified Mg(OH)₂ and MgCO₃ as dominant and then MgO and ZnO. Phase analysis also indicated the presence of ZnO coating after 100 h of immersion. The ZnO film deposited after 1500 ALD cycles on MgCa2Zn1Gd3 provides the most effective corrosion protection and is a promising solution for biodegradable magnesium implants. Full article

(This article belongs to the Special Issue Corrosion and Corrosion Protection of Metals/Alloys)

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11 pages, 2236 KB

Open AccessEditor’s ChoiceArticle

Microwave-Induced Hydrogen Plasma as a New Synthesis Process for High-Entropy Carbides

by Muhammad Shiraz Ahmad, Kallol Chakrabarty and Shane A. Catledge

Materials 2025, 18(24), 5520; https://doi.org/10.3390/ma18245520 - 9 Dec 2025

Cited by 1 | Viewed by 1120

Abstract

Microwave-Induced Hydrogen Plasma (MIHP) is introduced as a novel synthesis route for producing high-entropy carbides (HECs), offering an alternative to conventional mechanical alloying and/or sintering techniques. In this study, a representative HEC composition,

{MoNbTaVWC}_{5}

, was successfully synthesized using MIHP processing at [...] Read more.

Microwave-Induced Hydrogen Plasma (MIHP) is introduced as a novel synthesis route for producing high-entropy carbides (HECs), offering an alternative to conventional mechanical alloying and/or sintering techniques. In this study, a representative HEC composition,

{MoNbTaVWC}_{5}

, was successfully synthesized using MIHP processing at 200 Torr. The process employs microwave energy to generate hydrogen plasma to facilitate carbothermal reduction of metal oxide precursors. The plasma environment generates abundant reactive atomic hydrogen species, which enhance reaction spontaneity and promote efficient HEC formation. X-ray diffraction confirmed the formation of a single-phase rocksalt-type face-centered cubic structure. Scanning electron microscopy combined with energy-dispersive X-ray spectroscopy confirmed uniform elemental distribution within the synthesized microstructure. Nanoindentation measurements yielded hardness and elastic modulus values consistent with literature reports for similar compositions. X-ray photoelectron spectroscopy confirmed the chemical state of carbon to be primarily bonded with metals as carbides, with only minor oxygen present as metal-oxides. Raman spectroscopy performed over the 750–1900

{cm}^{- 1}

range yielded a featureless spectrum with no detectable D or G bands often observed for sp²-hybridized disordered carbon, graphite, or graphene materials. These results validate the structural and chemical purity of the synthesized HECs. This work aims to demonstrate the feasibility and reproducibility of MIHP as a synthesis method for HECs. Full article

(This article belongs to the Section Advanced and Functional Ceramics and Glasses)

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19 pages, 4311 KB

Open AccessEditor’s ChoiceArticle

Effect of Initial Relative Density on Liquid-Phase Sintering Behaviors of Al Powder Using Al–Cu Eutectic Alloy Aid: In Situ Observations Using Tomography and Microscopy

by Ryotaro Kusunoki, Erika Matsumoto, Takeshi Higaki, Asuka Suzuki, Makoto Kobashi, Yukiko Ozaki, Masato Hoshino and Masayuki Uesugi

Materials 2025, 18(24), 5499; https://doi.org/10.3390/ma18245499 - 7 Dec 2025

Cited by 3 | Viewed by 1242

Abstract

Aluminum (Al) powder with low sinterability is difficult to use in binder jetting (BJT) additive manufacturing, which involves sintering a metal powder after forming a green body. A liquid-phase sintering process for Al powder using Al–Cu eutectic alloy powder as a sintering aid [...] Read more.

Aluminum (Al) powder with low sinterability is difficult to use in binder jetting (BJT) additive manufacturing, which involves sintering a metal powder after forming a green body. A liquid-phase sintering process for Al powder using Al–Cu eutectic alloy powder as a sintering aid has recently been developed. In this study, to clarify the applicability of liquid-phase sintering to BJT additive manufacturing, the effect of the initial relative density of green bodies (ρ_rel,0 = 50–90%) on the final relative density was investigated. The final relative density was not significantly affected by ρ_rel,0 and achieved 96–97% after sintering at 630 °C for 1800 s. However, pores are likely to remain in the sintered body with a high ρ_rel,0 of 90%. In situ observations using synchrotron radiation X-ray computed tomography revealed that large pores were formed at the early sintering stage of the green body with ρ_rel,0 of 90% and partially retained after sintering. By contrast, the green body with ρ_rel,0 of 50% exhibited a significant rearrangement at the early sintering stage, promoting the densification. This study provides a deep understanding of liquid-phase sintering of Al powder, which is considered a suitable post-processing method for BJT additive manufacturing. Full article

(This article belongs to the Special Issue New Insight of Powder Metallurgy: Microstructure, Durability and Mechanical Properties—2nd Edition)

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13 pages, 2845 KB

Open AccessEditor’s ChoiceArticle

Comprehensive Characterization of a Reference Ferroelectric Nematic Liquid Crystal Material

by Ayusha Paul, Milon Paul, Manisha Badu, Arjun Ghimire, Netra Prasad Dhakal, Samuel Sprunt, Antal Jákli and James T. Gleeson

Materials 2025, 18(24), 5496; https://doi.org/10.3390/ma18245496 - 6 Dec 2025

Cited by 9 | Viewed by 3574

Abstract

Among the recently developed ferroelectric nematic liquid crystals, FNLC-919, synthesized by Merck Electronics KGaA, stands out for its stable, room-temperature, ferroelectric nematic (N_F) phase. This renders it a promising candidate for both fundamental research and device-level applications. In this study, we [...] Read more.

Among the recently developed ferroelectric nematic liquid crystals, FNLC-919, synthesized by Merck Electronics KGaA, stands out for its stable, room-temperature, ferroelectric nematic (N_F) phase. This renders it a promising candidate for both fundamental research and device-level applications. In this study, we present a comprehensive experimental investigation of FNLC-919, focusing on its structural, optical, dielectric, and elastic properties in the paraelectric nematic (N) and the intermediate antiferroelectric phase (dubbed N_X) that occur in a temperature range between the N and N_F phases. Key material parameters such as ferroelectric polarization, viscosity, and nanostructure are characterized as functions of temperature in all mesophases, while the orientational elastic constants are determined only in the N and N_X phases. Our findings are compared with prior results concerning the benchmark compound DIO that also exhibits the phase sequence N-N_X-N_F and reveals a smectic-like mass density wave coinciding with antiferroelectric ordering in the N_X phase. Full article

(This article belongs to the Section Soft Matter)

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12 pages, 2304 KB

Open AccessEditor’s ChoiceArticle

Analysis of Superjunction MOSFET (CoolMOS^TM) Concept Limitations—Part II: Simulations

by Zbigniew Lisik and Jacek Podgórski

Materials 2025, 18(23), 5468; https://doi.org/10.3390/ma18235468 - 4 Dec 2025

Cited by 1 | Viewed by 962

Abstract

The CoolMOS^TM (Infineon Technologies AG, Munich, Germany) has been regarded as a device that alleviates high-voltage limitations of unipolar power devices. However, although the theoretical considerations seem to confirm this possibility, this expectation has not been fulfilled to date. It appears that [...] Read more.

The CoolMOS^TM (Infineon Technologies AG, Munich, Germany) has been regarded as a device that alleviates high-voltage limitations of unipolar power devices. However, although the theoretical considerations seem to confirm this possibility, this expectation has not been fulfilled to date. It appears that there are some limitations in the CoolMOS^TM concept, and the paper deals with their identification. Part I concentrated on the theory of high-voltage superjunction and its implementation into a power VDMOS transistor, which resulted in the CoolMOS^TM structure. This part is aimed at the physical and technological limitations that have been identified, taking advantage of numerical investigations of CoolMOS^TM structures developed on the basis of a typical VDMOS one. Full article

(This article belongs to the Special Issue Metal Oxide Semiconductors: Synthesis, Structure, and Applications)

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