You seem to have javascript disabled. Please note that many of the page functionalities won't work as expected without javascript enabled.

Search for Articles:

Title / Keyword

Author / Affiliation / Email

Journal

Article Type

Advanced Search

Section

Special Issue

Volume

Issue

Number

Page

Logical OperatorOperator

Search Text

Search Type

Laser Powder Bed-Fused Scalmalloy: Effect of Long Thermal Aging on Hardness and Electrical Conductivity
Non-Ferrous Metal Bioleaching from Pyrometallurgical Copper Slag Using Spent Medium of Different Fungal Species

Journal Description

Metals

Metals is an international, peer-reviewed, open access journal published monthly online by MDPI. The Spanish Materials Society (SOCIEMAT) is affiliated with Metals and their members receive discounts on the article processing charges.

Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
High Visibility: indexed within Scopus, SCIE (Web of Science), Inspec, Ei Compendex, CAPlus / SciFinder, and other databases.
Journal Rank: JCR - Q2 (Metallurgy and Metallurgical Engineering) / CiteScore - Q1 (Metals and Alloys)
Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 18.7 days after submission; acceptance to publication is undertaken in 2.7 days (median values for papers published in this journal in the second half of 2025).
Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Companion journals for Metals include: Compounds, Alloys and Iron.

Impact Factor: 2.5 (2024); 5-Year Impact Factor: 2.8 (2024)

Imprint Information Journal Flyer Open Access ISSN: 2075-4701

Latest Articles

14 pages, 11061 KB

Open AccessArticle

On Microstructure Evolution and Magnetic Properties of Annealed FeNiCrMn Alloy

by Yu Zhang, Caili Ma, Jingwen Gao, Wenjie Chen, Song Zhang and Xia Huang

Metals 2026, 16(2), 141; https://doi.org/10.3390/met16020141 (registering DOI) - 24 Jan 2026

Fe-Ni-based alloys have attracted attention due to their potential for applications such as transmission line de-icing, where the core requirements include a Curie temperature near the freezing point and sufficient saturation magnetization. Accordingly, this study designed an Fe-29Ni-2Cr-1.5Mn (at.%) alloy with a Curie [...] Read more.

Fe-Ni-based alloys have attracted attention due to their potential for applications such as transmission line de-icing, where the core requirements include a Curie temperature near the freezing point and sufficient saturation magnetization. Accordingly, this study designed an Fe-29Ni-2Cr-1.5Mn (at.%) alloy with a Curie temperature around the freezing point, aiming to investigate the correlation between microstructural evolution and magnetic properties after cold rolling and annealing. The alloy was cold-rolled by 65% and subsequently annealed at 873 K for 0 to 60 min. The study reveals systematic evolutions in the alloy’s microstructure and magnetic properties. During the initial annealing stage, recovery substructures predominantly formed within the deformed grains, accompanied by a reduction in dislocation density and lattice constant. In the later annealing stage, the recrystallized fraction increased, although complete recrystallization was not achieved. Texture analysis indicates that the intensity of the Cube texture strengthened from 0.48 to 1.13. Correspondingly, the saturation magnetization and Curie temperature increased by approximately 9.76% and 10.25%, respectively, in the early annealing period, and then stabilized thereafter. The early-stage improvement in properties is likely related to stress relief and lattice distortion relaxation during the recovery stage. The calculated magnetocrystalline anisotropy constant of this alloy at 273 K is K₁ = 126 ± 18 J/m³, indicating that the <100> direction is its easy magnetization axis. This study provides insights into optimizing the magnetic properties of this alloy through controlled annealing. Full article

23 pages, 4690 KB

Open AccessArticle

Predicting the Ti-Al Binary Phase Diagram with an Artificial Neural Network Potential

by Micah Nichols, Mashroor S. Nitol, Saryu J. Fensin, Christopher D. Barrett and Doyl E. Dickel

Metals 2026, 16(2), 140; https://doi.org/10.3390/met16020140 (registering DOI) - 24 Jan 2026

The microstructure of the Ti-Al binary system is an area of great interest, as it affects material properties and plasticity. Phase transformations induce microstructural changes; therefore, accurately modeling the phase transformations of the Ti-Al system is necessary to describe plasticity. Interatomic potentials can [...] Read more.

The microstructure of the Ti-Al binary system is an area of great interest, as it affects material properties and plasticity. Phase transformations induce microstructural changes; therefore, accurately modeling the phase transformations of the Ti-Al system is necessary to describe plasticity. Interatomic potentials can be a powerful tool to model how materials behave; however, existing potentials lack accuracy in certain aspects. While classical potentials like the Modified Embedded Atom Method (MEAM) perform adequately for modeling a dilute Al solute within Ti’s

α

phase, they struggle with accurately predicting plasticity. In particular, they struggle with stacking fault energies in intermetallics and to some extent elastic properties. This hinders their effectiveness in investigating the plastic behavior of formed intermetallics in Ti-Al alloys. Classical potentials also fail to predict the

α

-to-

β

phase boundary. Existing machine learning (ML) potentials reproduce the properties of formed intermetallics with density functional theory (DFT) but do not accurately capture the

α

-to-

β

or

α

-to-D0₁₉ phase boundaries. This work uses a rapid artificial neural network (RANN) framework to produce a neural network potential for the Ti-Al binary system. This potential is capable of reproducing the Ti-Al binary phase diagram up to 30% Al concentration. The present interatomic potential ensures stability and allows results near the accuracy of DFT. Using Monte Carlo simulations, the RANN potential accurately predicts the

α

-to-

β

and

α

-to-D0₁₉ phase transitions. The current potential also exhibits accurate elastic constants and stacking fault energies for the L1₀ and D0₁₉ phases. Full article

► Show Figures

Figure 1

20 pages, 1939 KB

Open AccessArticle

Fiber-Diode Hybrid Laser Welding of IGBT Copper Terminals

by Miaosen Yang, Qiqi Lv, Shengxiang Liu, Qian Fu, Xiangkuan Wu, Yue Kang, Xiaolan Xing, Zhihao Deng, Fuxin Yao and Simeng Chen

Metals 2026, 16(2), 139; https://doi.org/10.3390/met16020139 - 23 Jan 2026

The traditional ultrasonic bonding technique for IGBT T2 copper terminals often causes physical damage to ceramic substrates, severely compromising the reliability of power modules. Meanwhile, T2 copper laser welding faces inherent challenges including low laser absorption efficiency and unstable molten pool dynamics. To [...] Read more.

The traditional ultrasonic bonding technique for IGBT T2 copper terminals often causes physical damage to ceramic substrates, severely compromising the reliability of power modules. Meanwhile, T2 copper laser welding faces inherent challenges including low laser absorption efficiency and unstable molten pool dynamics. To address these issues, this study targets the high-quality connection of IGBT T2 copper terminals and proposes a welding solution integrating a Fiber-Diode Hybrid Laser system with galvo-scanning technology. Comparative experiments between galvo-scanning and traditional oscillation methods CNC scanning were conducted under sinusoidal and circular trajectories to explore the regulation mechanism of welding quality. The results demonstrate that CNC scanning lacks precision in thermal input control, resulting in inconsistent welding quality. Galvo-scanning enables precise modulation of laser energy distribution and molten pool behavior, effectively reducing spatter and porosity defects. It also promotes the transition from columnar grains to equiaxed grains, significantly refining the weld microstructure. Under the sinusoidal trajectory with a welding speed of 20 mm/s, the Lap-shear strength of the galvo-scanned joint reaches 277 N/mm², outperforming all CNC-scanned joints. This research proposes a non-contact welding strategy targeted at eliminating the mechanical failure mechanism associated with conventional ultrasonic bonding of ceramic substrates. It establishes the superiority of galvo-scanning for precision welding of high-reflectivity materials and lays a foundation for its potential application in new energy vehicle power modules and microelectronic packaging. Full article

(This article belongs to the Special Issue Advanced Laser Welding and Joining of Metallic Materials)

► Show Figures

Graphical abstract

15 pages, 1196 KB

Open AccessArticle

Machine Learning-Assisted Fabrication for K417G Alloy Prepared by Wide-Gap Brazing: Process Parameters, Microstructure, and Properties

by Zhun Cheng, Min Wu, Bo Wei, Xinhua Wang, Xiaoqiang Li and Jiafeng Fan

Metals 2026, 16(2), 138; https://doi.org/10.3390/met16020138 - 23 Jan 2026

This study employed data-driven machine learning models to analyze the effects of filler material composition and other process parameters on mechanical properties during the crack repair of nickel-based superalloys such as K417G using wide-gap brazing technology. First, a linear regression model was used [...] Read more.

This study employed data-driven machine learning models to analyze the effects of filler material composition and other process parameters on mechanical properties during the crack repair of nickel-based superalloys such as K417G using wide-gap brazing technology. First, a linear regression model was used to analyze the influence of independent variables (filler material composition and other process parameters) on the dependent variables (tensile strength and elongation). The regression results indicated that temperature and filler composition significantly affected tensile strength and elongation. Subsequently, a TabNet machine learning model was applied to simulate the relationship between parameters such as composition and mechanical properties. The experimental results showed that when four parameters, namely, the filler composition, temperature, holding time, and pressure, were used as input features, the deviation between the actual and predicted values of elongation was minimal, with a value of only 1.5650. Full article

(This article belongs to the Special Issue Advanced Metal Welding and Joining Technologies—3rd Edition)

21 pages, 6679 KB

Open AccessArticle

Influence of Lignosulfonate on the Hydrothermal Interaction Between Pyrite and Cu(II) Ions in Sulfuric Acid Media

by Kirill Karimov, Maksim Tretiak, Uliana Sharipova, Tatiana Lugovitskaya, Oleg Dizer and Denis Rogozhnikov

Metals 2026, 16(2), 137; https://doi.org/10.3390/met16020137 - 23 Jan 2026

Hydrometallurgical pretreatment of pyrite-bearing concentrates and tailings by hydrothermal interaction with Cu(II) solutions is a promising route for chemical beneficiation and mitigation of acid mine drainage but is limited by passivation caused by elemental sulfur and secondary copper sulfides. Here, the effect of [...] Read more.

Hydrometallurgical pretreatment of pyrite-bearing concentrates and tailings by hydrothermal interaction with Cu(II) solutions is a promising route for chemical beneficiation and mitigation of acid mine drainage but is limited by passivation caused by elemental sulfur and secondary copper sulfides. Here, the effect of sodium lignosulfonate (SLS) on the hydrothermal reaction between natural pyrite and CuSO₄ in H₂SO₄ media at 180–220 °C was studied at [H₂SO₄]₀ = 10–30 g/dm³, [Cu]₀ = 6–24 g/dm³, and [SLS]₀ = 0–1.0 g/dm³. Process efficiency was evaluated by Fe extraction into solution and Cu precipitation on the solid phase, and products were characterized by XRD and SEM/EDS. SLS markedly intensified pyrite conversion: at 200 °C and 120 min, Fe extraction increased from 14 to 26% and Cu precipitation from 5 to 23%, while at 220 °C, Fe extraction reached 33.4% and Cu precipitation 26.8%. XRD confirmed the sequential transformation CuS → Cu_1.8S. SEM/EDS showed that SLS converts localized nucleation of Cu_xS on defect sites into the formation of a fine, loosely packed, and well-dispersed copper sulfide phase. The results demonstrate that lignosulfonate surfactants efficiently suppress passivation and enhance mass transfer, providing a basis for intensifying hydrothermal pretreatment of pyrite-bearing industrial materials. Full article

(This article belongs to the Special Issue Recent Progress in Metal Extraction and Recycling)

► Show Figures

Figure 1

22 pages, 63134 KB

Open AccessArticle

The Effects of Laser Shock Peening with and Without Protective Coating on the Corrosion Resistance of Sensitized 304L Stainless Steel

by Richard Chiang and Vijay K. Vasudevan

Metals 2026, 16(2), 136; https://doi.org/10.3390/met16020136 - 23 Jan 2026

This study examined the effects of laser shock peening (LSP) and LSP without protective coating (LSPwC) on the microstructure and corrosion behavior of 304L stainless steel using cyclic polarization testing. LSP enhanced corrosion resistance under mild sensitization (650 °C; 5 h) by inducing [...] Read more.

This study examined the effects of laser shock peening (LSP) and LSP without protective coating (LSPwC) on the microstructure and corrosion behavior of 304L stainless steel using cyclic polarization testing. LSP enhanced corrosion resistance under mild sensitization (650 °C; 5 h) by inducing compressive stress and increasing dislocation density, stabilizing the passive film. Limited improvement was observed under severe sensitization (650 °C; 24 h). Deformation-induced martensite detected by XRD was attributed to mechanical polishing, not LSP. In contrast, LSPwC reduced corrosion resistance across all conditions due to Fe-rich surface oxides that impaired passivation. Full article

(This article belongs to the Special Issue Laser Shock Peening: From Fundamentals to Applications)

► Show Figures

Graphical abstract

15 pages, 3899 KB

Open AccessArticle

Thermodynamic and Experimental Investigation of Lead Removal from Pb-Sb Alloy Using an H₃PO₄-(NaPO₃)₆ Composite Agent

by Jiahui Tan, Xiangfeng Kong, Jia Yang, Dachun Liu and Hongwei Yang

Metals 2026, 16(2), 135; https://doi.org/10.3390/met16020135 - 23 Jan 2026

This study presents a rapid and efficient laboratory-scale process for removing lead from Pb–Sb alloy melts using a composite H₃PO₄–(NaPO₃)₆ flux. Thermodynamic analysis was combined with experimental investigation to elucidate the influence of key parameters on [...] Read more.

This study presents a rapid and efficient laboratory-scale process for removing lead from Pb–Sb alloy melts using a composite H₃PO₄–(NaPO₃)₆ flux. Thermodynamic analysis was combined with experimental investigation to elucidate the influence of key parameters on lead removal behavior. The Wilson equation was employed to describe the non-ideal behavior of the Pb–Sb system, enabling estimation of equilibrium lead contents and providing theoretical support for interpreting experimental trends. Under the investigated conditions (1073 K, H₃PO₄/(NaPO₃)₆ mass ratio of 2:1, and a holding time of 10 min), the Pb mass fraction was reduced from 10.0 wt.% to 0.018 wt.%, corresponding to a lead removal efficiency of 99.86%. Compared with the traditional refining processes, this method shortens the processing time and avoids the use of volatile gas reagents, demonstrating its potential for lead–antimony separation. The results provide thermodynamic and experimental insight into phosphate-based refining of crude antimony. Full article

(This article belongs to the Section Extractive Metallurgy)

► Show Figures

Graphical abstract

16 pages, 24835 KB

Open AccessArticle

Linking Microstructural Evolution to Magnetic Response for Damage Assessment in In-Service 321 Stainless Steel

by Shengzhong Hu, Yunrong Lyu, Weiming Li and Fuping Guo

Metals 2026, 16(2), 134; https://doi.org/10.3390/met16020134 - 23 Jan 2026

This study evaluated the damage behavior of 321 austenitic stainless steel under tensile loading by measuring its magnetic properties. The results indicate that, at room temperature, the magnetic properties of 321 stainless steel respond distinctly to mechanical loading. Changes under external stress are [...] Read more.

This study evaluated the damage behavior of 321 austenitic stainless steel under tensile loading by measuring its magnetic properties. The results indicate that, at room temperature, the magnetic properties of 321 stainless steel respond distinctly to mechanical loading. Changes under external stress are primarily attributed to the phase transformation from austenite to martensite. Both coercive force and magnetic Barkhausen noise effectively characterize this material’s deformation and phase transformation processes: the coercive force dynamics curve exhibits an initial rise, followed by a decline with a decrease during the specimen’s necking stage. Magnetic Barkhausen noise is highly sensitive to stress changes, especially during the elastic stage. In situ measurements show that, at a stress of 300 MPa, the magnetic Barkhausen noise peak voltage signal reaches 0.060 V, which is a 100.0% increase compared to the original specimen (0.030 V). Therefore, when assessing the stress state and damage of stainless steel using coercive force and magnetic Barkhausen noise techniques, attention should be paid to the inflection characteristics of the coercive force dynamic curve and the inflection points in the peak values of the magnetic Barkhausen noise voltage signal. These features can be used to effectively monitor crack initiation and propagation in austenitic stainless steel. Full article

► Show Figures

Figure 1

23 pages, 4591 KB

Open AccessArticle

From Mining Residues to Potential Resources: A Cross-Disciplinary Strategy for Raw Materials Recovery and Supply

by Stefano Ubaldini, Alena Luptakova, Matteo Paciucci, Daniela Caschera, Roberta Grazia Toro, Isabel Nogues, Victor Pinon, Magdalena Balintova, Adriana Estokova, Miloslav Luptak, Eva Macingova, Rosamaria Salvatori and Daniela Guglietta

Metals 2026, 16(2), 133; https://doi.org/10.3390/met16020133 - 23 Jan 2026

Digital and green energy transitions are driving an unprecedented demand for Strategic and Critical Raw Materials (S-CRMs), necessitating the identification of alternative sources such as secondary raw materials from exploration and mining residues. This study investigates an integrated, multi-scale approach to map and [...] Read more.

Digital and green energy transitions are driving an unprecedented demand for Strategic and Critical Raw Materials (S-CRMs), necessitating the identification of alternative sources such as secondary raw materials from exploration and mining residues. This study investigates an integrated, multi-scale approach to map and recover S-CRMs from an abandoned exploration stockpile in Zlatá Baňa, Slovak Republic. A key aspect of the methodology is comprehensive chemical and mineralogical characterization (XRF, PXRD, FTIR, LIBS, and SEM-EDS), which provided scientific validation for the diagnostic absorption features observed in laboratory reflectance spectra. These laboratory-acquired signatures were then used as endmembers to classify Sentinel-2 imagery via the Spectral Angle Mapper (SAM) algorithm. This integration enabled the identification of three distinct residue classes, with classA (jarosite-rich residues) emerging as the most reactive facies. Subsequent bioleaching experiments using Acidithiobacillus ferrooxidans demonstrated that microbial activity more than doubled Zn mobilization compared to abiotic controls. This cross-disciplinary strategy confirms that the synergy between advanced analytical characterization and remote sensing provides a robust, cost-effective pathway for the sustainable recovery of S-CRMs in regions affected by historical and mining activities. Full article

(This article belongs to the Special Issue Efficient Utilization of Metal Mineral Resources and Low-Carbon Metallurgy)

► Show Figures

Graphical abstract

19 pages, 17087 KB

Open AccessArticle

Microstructural and Wear Characterisation of Aluminium 7075-Based Metal Matrix Composites Reinforced with High-Entropy Alloy Particles and Manufactured via Friction Stir Processing

by Leire Garcia-Sesma, Javier Vivas, Iban Quintana and Egoitz Aldanondo

Metals 2026, 16(2), 132; https://doi.org/10.3390/met16020132 - 23 Jan 2026

This study investigates the microstructural evolution and wear behaviour of aluminium 7075-based metal matrix composites (MMCs) reinforced with high-entropy alloy (HEA) particles and fabricated via friction stir processing (FSP). A detailed characterisation of the grain refinement in the 7075 matrix was conducted, revealing [...] Read more.

This study investigates the microstructural evolution and wear behaviour of aluminium 7075-based metal matrix composites (MMCs) reinforced with high-entropy alloy (HEA) particles and fabricated via friction stir processing (FSP). A detailed characterisation of the grain refinement in the 7075 matrix was conducted, revealing significant dynamic recrystallization and grain size reduction induced by the severe plastic deformation inherent to FSP. The interaction between the matrix and HEA particles was analysed, showing strong interfacial bonding, which was further influenced by post-processing heat treatments. These microstructural modifications were correlated with the wear performance of the composites, demonstrating enhanced resistance due to the synergistic effect of precipitates and particle reinforcement. The findings highlight the potential of FSP as a viable route for tailoring surface properties in advanced MMCs for demanding tribological applications. Full article

(This article belongs to the Special Issue Surface Treatments and Coating of Metallic Materials (2nd Edition))

► Show Figures

Figure 1

18 pages, 3018 KB

Open AccessArticle

Integrated Modeling and Multi-Criteria Analysis of the Turning Process of 42CrMo4 Steel Using RSM, SVR with OFAT, and MCDM Techniques

by Dejan Marinkovic, Kenan Muhamedagic, Simon Klančnik, Aleksandar Zivkovic, Derzija Begic-Hajdarevic and Mirza Pasic

Metals 2026, 16(2), 131; https://doi.org/10.3390/met16020131 - 23 Jan 2026

This paper analyzes different approaches for the mathematical modeling and optimization of process parameters in the hard turning process of 42CrMo4 steel using a hybrid approach combining response surface methodology (RSM), multi-criteria decision making (MCDM), and machine learning through, support vector regression (SVR) [...] Read more.

This paper analyzes different approaches for the mathematical modeling and optimization of process parameters in the hard turning process of 42CrMo4 steel using a hybrid approach combining response surface methodology (RSM), multi-criteria decision making (MCDM), and machine learning through, support vector regression (SVR) with one-factor-at-a-time (OFAT) sensitivity analysis. Controlled process parameters such as cutting speed, depth of cut, feed, and insert radius are applied to conduct the experiments based on a full factorial experimental design. RSM was used to develop models that describe the effect of controlled parameters on surface roughness and cutting forces. Special emphasis was placed on the analysis of standardized residuals to evaluate the predictive capabilities of the RSM-developed model on an unseen data set. For all four outputs considered, analysis of the standardized residuals shows that over 97% of the points lie within ±3 standard deviations. A multi-criteria optimization technique was applied to establish an optimal combination of input parameters. The SVR model had high performance for all outputs, with coefficient of determination values between 89.91% and 99.39%, except for surface roughness on the test set, with a value of 9.92%. While the SVR model achieved high predictive accuracy for cutting forces, its limited generalization capability for surface roughness highlights the higher complexity and stochastic nature of surface formation mechanisms in the turning process. OFAT analysis showed that feed rate and depth of cut have been shown to be the most important input variables for all analyzed outputs. Full article

(This article belongs to the Special Issue Smart Sensing and Artificial Intelligence in Metal Processing and Machining)

19 pages, 5147 KB

Open AccessArticle

The Influence of Applying PVD Coatings on Adhesion Wear Resistance of Quenching and Tempering Steels

by Ivica Kladarić, Stjepan Golubić, Danko Ćorić and Andrijana Milinović

Metals 2026, 16(2), 130; https://doi.org/10.3390/met16020130 - 23 Jan 2026

The article examines the effect of different types of two-layer nanostructured coatings (cVIc and nACVIc) deposited on three types of steel substrates, 45S20, C45E, and 42CrMo4, to determine the resistance to adhesive wear of the substrate/coating system. The samples underwent different heat treatments, [...] Read more.

The article examines the effect of different types of two-layer nanostructured coatings (cVIc and nACVIc) deposited on three types of steel substrates, 45S20, C45E, and 42CrMo4, to determine the resistance to adhesive wear of the substrate/coating system. The samples underwent different heat treatments, including normalising, quenching, and quenching and tempering, followed by PVD (physical vapour deposition) treatment at temperatures of 450 °C (cVIc) and 460 °C (nACVIc). The thickness of the cVIc layers for all three steels ranged from 0.9 to 3.4 μm, while the thickness of the nACVIc layers on all steels was slightly greater, ranging from 1.9 to 3.1 μm. Tribological tests were conducted using the pin-on-disc method, and the results were statistically analysed. Results indicate that steel grade, heat treatment, and PVD coating significantly affect adhesive wear resistance, with the type of PVD coating showing the strongest influence. For all three steels, quenched and uncoated samples exhibited the lowest adhesion wear index values. Normalised and quenched with or without tempering steels coated with cVIc layer exhibit higher resistance to adhesive wear due to better adhesion of the layer compared to the nACVIc coating. Full article

► Show Figures

Graphical abstract

14 pages, 4680 KB

Open AccessArticle

Performance Evaluation of Five-Axis CNC Milling via Spindle Current and Vibration Monitoring

by Beatriz Cardoso, José Ferreira, Tiago E. F. Silva, Pedro Sá Couto, Ana Reis and Abílio M. P. de Jesus

Metals 2026, 16(1), 129; https://doi.org/10.3390/met16010129 - 22 Jan 2026

The digitalization of machining processes is increasingly recognized as essential for achieving higher productivity, reliability, and traceability. However, access to reliable in-process sensor data remains limited, particularly in multi-axis CNC machining, where dimensional accuracy and surface integrity strongly depend on stable and optimized [...] Read more.

The digitalization of machining processes is increasingly recognized as essential for achieving higher productivity, reliability, and traceability. However, access to reliable in-process sensor data remains limited, particularly in multi-axis CNC machining, where dimensional accuracy and surface integrity strongly depend on stable and optimized process conditions. This study investigates sensor-based monitoring as a practical approach for evaluating process performance in five-axis CNC milling. Electric current and vibration signals were acquired during three machining operations, under distinct cutting parameters, using current clamps and a plug-and-play MEMS accelerometer. The signals were processed using the root mean square method to assess the correlation between sensor data and machining conditions. Dimensional inspection of each workpiece was carried out to verify geometric conformity. The results show that spindle current measurements exhibit a strong linear correlation with material removal rate and cutting power, supporting their use as indicators of cutting forces and energy consumption. Vibration signals revealed pronounced dynamic behaviour for specific tool orientations, particularly in transverse to tool axis direction. The proposed methodology provides a simple and low-cost framework for integrating sensor-based monitoring into five-axis CNC milling, particularly relevant for semi-roughing operations, and offers a basis for future studies on process optimization and real-time condition monitoring. Full article

(This article belongs to the Special Issue Numerical and Experimental Advances in Metal Processing, 2nd Edition)

► Show Figures

Graphical abstract

17 pages, 8142 KB

Open AccessArticle

The Combined Influence of the Detonator Position and Anvil Type on the Weld Quality of Explosively Welded A1050/AZ31 Joints

by Bir Bahadur Sherpa, Shu Harada, Saravanan Somasundaram, Shigeru Tanaka and Kazuyuki Hokamoto

Metals 2026, 16(1), 128; https://doi.org/10.3390/met16010128 - 22 Jan 2026

The present study systematically investigates, for the first time, the combined influences of detonator position (top-edge and bottom-edge initiations) and anvil material (steel and sand) on the interfacial microstructure and mechanical performance of explosively welded A1050/AZ31 dissimilar joints. When welding was conducted using [...] Read more.

The present study systematically investigates, for the first time, the combined influences of detonator position (top-edge and bottom-edge initiations) and anvil material (steel and sand) on the interfacial microstructure and mechanical performance of explosively welded A1050/AZ31 dissimilar joints. When welding was conducted using a steel anvil with the detonator positioned at the top edge, significant cracking occurred both at the surface and along the weld interface. In contrast, placing the detonator at the bottom edge noticeably reduced these defects. Moreover, the use of a sand anvil nullified these defects by damping the reflecting shockwaves and minimizing vibrations. Hardness measurements revealed substantial increase at the interface under all the conditions, with the highest value observed with the steel anvil. Welds subjected to top-edge detonation showed higher hardness values compared to those of welds subjected to bottom-edge detonation. Overall, the results suggest that sand anvils with bottom-edge detonation provide the optimal weld quality. The rigid steel anvil reflects the shockwave, generating high pressure and velocity at the interface, whereas the sand anvil absorbs a part of the shock energy, suppressing high-magnitude reflections. The position of the detonator influences the propagation dynamics of the detonation wave and the resulting collision velocity, which in turn, affect the interfacial morphology and overall quality of the weld. Full article

► Show Figures

Figure 1

16 pages, 11984 KB

Open AccessArticle

Research on the Shear Forces and Fracture Behavior of Self-Riveting Friction Stir Lap Welding Joints with Medium-Thick Aluminum/Steel Plates

by Xiongwen Tian, Jianxin Wang, Chang Zhai, Yabin He, Shujin Chen, Yiming Jin, Rui Yu and Sergii Maksymov

Metals 2026, 16(1), 127; https://doi.org/10.3390/met16010127 - 22 Jan 2026

The self-riveting friction stir lap welding (SRFSLW) method was utilized to improve the bonding strength of lap welding joints with medium-thick aluminum/steel plates and to realize structural lightweighting. The effect of plunge depth on the shear force and the microstructure of the joint [...] Read more.

The self-riveting friction stir lap welding (SRFSLW) method was utilized to improve the bonding strength of lap welding joints with medium-thick aluminum/steel plates and to realize structural lightweighting. The effect of plunge depth on the shear force and the microstructure of the joint was studied, and the influence of groove structure (rectangular groove and dovetail groove) on the failure behavior of the joint under shear load was obtained, simultaneously. The EBSD results indicate that the aluminum alloy grains in the stir zone (SZ) of groove joints have been refined compared to the non-groove joint. Meanwhile, due to the presence of grooves, the proportion of high-angle grain boundaries of the SZ is increased, and more dynamic recrystallization has emerged; thus, the KAM value of the SZ is reduced to a certain extent. The non-groove joint exhibits {111}//ND fiber texture, while the groove joint shows F-plate texture. In self-riveting joints, due to the increased metallurgical bonding area and the weakened effect of external loads, the failure of metallurgical bonding in the joint requires higher external load, and the separation of the self-riveted structure from the groove requires greater bending moment, thereby improving the strength of the joint. Full article

(This article belongs to the Special Issue Properties and Residual Stresses of Welded Alloys)

► Show Figures

Figure 1

17 pages, 5227 KB

Open AccessArticle

Synergistic Regulation of Microstructure and Mechanical Property in TiAl Alloys via Rolling and Cyclic Heat Treatment

by Shiwei Tian, Zhiqian Liao, Dejun Song, Chong Li, Kuishan Sun, Lin Yuan and Haitao Jiang

Metals 2026, 16(1), 126; https://doi.org/10.3390/met16010126 - 22 Jan 2026

The presence of the brittle β/B2 phase in TiAl alloys often deteriorates their mechanical properties, posing a significant challenge for manufacturing large-sized, high-performance sheets. To address this issue, this study systematically investigates the synergistic effect of pack rolling and subsequent heat treatment on [...] Read more.

The presence of the brittle β/B2 phase in TiAl alloys often deteriorates their mechanical properties, posing a significant challenge for manufacturing large-sized, high-performance sheets. To address this issue, this study systematically investigates the synergistic effect of pack rolling and subsequent heat treatment on the microstructure evolution and mechanical properties of a Ti-44Al-4Nb-1.5Mo-0.1B-0.1Y alloy. Sheets with two different deformation levels (R7: 69.8% and R11: 83.0% reduction) were prepared via pack rolling. This was followed by a series of heat treatments at different temperatures (1150–1350 °C) and cyclic heat treatments at 1250 °C (3, 6, and 9 cycles). The results demonstrate that the higher deformation level (R11) promoted extensive dynamic recrystallization, resulting in a uniform microstructure of equiaxed γ, α₂, and β phases, while the lower deformation (R7) retained a significant fraction of deformed γ/α₂ lamellae. Heat treatment at 1250 °C was identified as optimal for transforming the microstructure into fine lamellar colonies while effectively reducing the β/B2 phase. Cyclic heat treatment at this temperature further decreased the β-phase content to 4.1% after 9 cycles. The elimination mechanism was determined to follow the β→ α → γ + α₂ phase transformation sequence, driven by the combined effect of rolling-induced defects and cyclic thermal stress. Cyclic heat treatment at this temperature was particularly effective in generating a high density of nucleation sites within the lamellar colonies, leading to significant refinement of the lamellar structure. Consequently, the R11 sheet subjected to 9 cycles of heat treatment exhibited a 15.5% increase in tensile strength and an 8.3% improvement in elongation compared to the hot-isostatically pressed state. This enhancement is primarily attributed to the significant refinement of lamellar colonies and the reduction in interlamellar spacing. This work presents an effective integrated processing strategy for fabricating high-performance TiAl alloy sheets with superior strength and toughness. Full article

(This article belongs to the Special Issue Microstructure and Deformation Mechanisms of Alloys)

► Show Figures

Figure 1

20 pages, 2130 KB

Open AccessArticle

Microstructural, Hardness, and Abrasive Wear Properties of Functionally Graded Al/ZrB₂ Composites Produced by In Situ Centrifugal Casting

by İbrahim Güney, Ömer Faruk Demirok, Yunus Emre Benkli, Çağlar Yüksel and Ömer Savaş

Metals 2026, 16(1), 125; https://doi.org/10.3390/met16010125 - 21 Jan 2026

Functionally graded aluminum matrix composites are of interest for applications requiring region-dependent mechanical and tribological performance. In this study, the micro-structure, hardness, and abrasive wear properties of functionally graded Al/ZrB₂ compo-site materials produced by an in situ centrifugal casting method were investigated. [...] Read more.

Functionally graded aluminum matrix composites are of interest for applications requiring region-dependent mechanical and tribological performance. In this study, the micro-structure, hardness, and abrasive wear properties of functionally graded Al/ZrB₂ compo-site materials produced by an in situ centrifugal casting method were investigated. The ZrB₂ reinforcement phase was synthesized in situ within the molten aluminum matrix, and functional grading was achieved through the action of centrifugal force during solidification. Samples taken from cylindrical castings were characterized using optical microscopy, scanning electron microscopy (SEM), X-Ray diffraction (XRD), density measurements, Brinell hardness testing, and abrasive wear experiments. Phase analyses con-firmed the successful in situ formation of ZrB₂ and verified that the phase distribution in-creased toward the direction of centrifugal force. Hardness increased with reinforcement content, rising from approximately 28 HB in the matrix-rich region to 68 HB and 72 HB in regions reinforced with 12% and 15% ZrB₂, respectively. Abrasive wear behavior was evaluated using the pin-on-disk method, and a Taguchi L (3⁵) orthogonal array was employed for experimental design. Statistical analyses showed that the composite region was the most influential parameter affecting wear performance, followed by abrasive particle size and applied load, while sliding distance and sliding speed were not statistically significant. These findings demonstrate that in situ centrifugal casting is an effective approach for producing functionally graded Al/ZrB₂ composites with improved hardness and wear resistance. Full article

► Show Figures

Figure 1

44 pages, 2586 KB

Open AccessReview

Cellular Automata and Phase-Field Modeling of Microstructure Evolution in Metal Additive Manufacturing: Recent Advances, Hybrid Frameworks, and Pathways to Predictive Control

by Łukasz Łach

Metals 2026, 16(1), 124; https://doi.org/10.3390/met16010124 - 21 Jan 2026

Metal additive manufacturing (AM) generates complex microstructures through extreme thermal gradients and rapid solidification, critically influencing mechanical performance and industrial qualification. This review synthesizes recent advances in cellular automata (CA) and phase-field (PF) modeling to predict grain-scale microstructure evolution during AM. CA methods [...] Read more.

Metal additive manufacturing (AM) generates complex microstructures through extreme thermal gradients and rapid solidification, critically influencing mechanical performance and industrial qualification. This review synthesizes recent advances in cellular automata (CA) and phase-field (PF) modeling to predict grain-scale microstructure evolution during AM. CA methods provide computational efficiency, enabling large-domain simulations and excelling in texture prediction and multi-layer builds. PF approaches deliver superior thermodynamic fidelity for interface dynamics, solute partitioning, and nonequilibrium rapid solidification through CALPHAD coupling. Hybrid CA–PF frameworks strategically balance efficiency and accuracy by allocating PF to solidification fronts and CA to bulk grain competition. Recent algorithmic innovations—discrete event-inspired CA, GPU acceleration, and machine learning—extend scalability while maintaining predictive capability. Validated applications across Ni-based superalloys, Ti-6Al-4V, tool steels, and Al alloys demonstrate robust process–microstructure–property predictions through EBSD and mechanical testing. Persistent challenges include computational scalability for full-scale components, standardized calibration protocols, limited in situ validation, and incomplete multi-physics coupling. Emerging solutions leverage physics-informed machine learning, digital twin architectures, and open-source platforms to enable predictive microstructure control for first-time-right manufacturing in aerospace, biomedical, and energy applications. Full article

(This article belongs to the Special Issue Characterization and Modeling of Microstructure Evolution During Metallic Material Processing)

► Show Figures

Figure 1

18 pages, 5019 KB

Open AccessArticle

A High-Solid-Content and Low-Surface-Treatment Epoxy-Polysiloxane Ceramic Metal Coating for Metal Anti-Corrosion in Harsh Environments

by Xiufen Liao, Liang Fan, Qiumei Jiang, Maomi Zhao, Songqiang Huang, Junxiang Lai, Congtao Sun and Baorong Hou

Metals 2026, 16(1), 123; https://doi.org/10.3390/met16010123 - 21 Jan 2026

Conventional anticorrosive coatings suffer from limitations of low solid content and rigorous surface pretreatment, posing environmental and cost challenges in field applications. In this study, a novel high-solid-content (>95%) epoxy-polysiloxane (Ep-PSA) ceramic metal coating was prepared that enables low-surface-treatment application. The originality lies [...] Read more.

Conventional anticorrosive coatings suffer from limitations of low solid content and rigorous surface pretreatment, posing environmental and cost challenges in field applications. In this study, a novel high-solid-content (>95%) epoxy-polysiloxane (Ep-PSA) ceramic metal coating was prepared that enables low-surface-treatment application. The originality lies in the synergistic combination of nano-sized ceramic powders, high-strength metallic powders, polysiloxane resin (PSA), and solvent-free epoxy resin (Ep), which polymerize through an organic–inorganic interpenetrating network to form a dense shielding layer. The as-prepared Ep-PSA coating system chemically bonds with indigenous metal substrate via Zn₃(PO₄)₂ and resin functionalities during curing, forming a conversion layer that reduces surface preparation requirements. Differentiating from existing high-solid coatings, this approach achieves superior long-term barrier properties, evidenced by |Z|_0.01Hz value of 9.64 × 10⁸ Ω·cm², after 6000 h salt spray exposure—four orders of magnitude higher than commercial 60% epoxy zinc-rich coatings (2.26 × 10⁴ Ω·cm², 3000 h salt spray exposure). The coating exhibits excellent adhesion (14.28 MPa) to standard sandblasted steel plates. This environmentally friendly, durable, and easily applicable composite coating demonstrates significant field application value for large-scale energy infrastructure. Full article

(This article belongs to the Special Issue Surface Treatments and Coating of Metallic Materials (2nd Edition))

► Show Figures

Figure 1

23 pages, 136328 KB

Open AccessArticle

Mechanical Wear and Friction Behavior of 30CrMnSiNi2A Steel Rocket Sled Sliders Under High-Speed and Heavy-Load Conditions: A Finite Element Analysis

by Ye Hao, Naiming Lin, Lin Wu, Kai Yan, Weihua Wang, Yuan Yu, Qing Zhou, Zhiqi Liu, Qunfeng Zeng, Dongyang Li and Yucheng Wu

Metals 2026, 16(1), 122; https://doi.org/10.3390/met16010122 - 20 Jan 2026

The rocket sled slider is a key connection component between the rocket sled and the track for support, guidance and load-bearing, ensuring the system’s safe and reliable operation. Wear of sliders under high—velocity and heavy—load conditions is crucial for equipment reliability. This study [...] Read more.

The rocket sled slider is a key connection component between the rocket sled and the track for support, guidance and load-bearing, ensuring the system’s safe and reliable operation. Wear of sliders under high—velocity and heavy—load conditions is crucial for equipment reliability. This study establishes a wear prediction model for sled rails using ANSYS, incorporating a dimensionless acceleration factor into the simulation. By analyzing dynamic characteristics of contact friction stress, wear volume, depth, and stress over time, the tribological characteristics of 30CrMnSiNi2A steel sliders were studied. The simulation results showed that during dry—friction sliding, slider wear is highly related to speed and load, increasing significantly as they increase. The slider’s contact surface has non-uniform stress distribution with stress concentration and gradient changes. Quantitative analysis has revealed that friction stress is positively correlated with load, and its sensitivity to speed changes is high at low speeds and relatively low at high speeds. Full article

(This article belongs to the Special Issue Advances in Tribological Performance and Wear Mechanism of Metallic Materials)

► Show Figures

Figure 1

More Articles...

Submit to Metals Review for Metals

Journal Menu

Journal Browser

► Journal Browser

Highly Accessed Articles

View More...

Latest Books

More Books and Reprints...

E-Mail Alert

News

6 November 2025
MDPI Launches the Michele Parrinello Award for Pioneering Contributions in Computational Physical Science

21 January 2026
Metals | Recruiting Section Editor-in-Chief for the “Structural Integrity of Metals” Section

16 January 2026
Interview with Mr. Jiasheng Wang—Winner of the Metals Travel Award

More News & Announcements...

Topics

Propose a Topic

Topic in JFB, Materials, Metals, Nanomanufacturing, Nanomaterials

Physical Methods for the Synthesis of Materials and Their Applications Topic Editors: Vincenzo Amendola, Gregory Guisbiers
Deadline: 31 March 2026

Topic in Applied Sciences, Buildings, Construction Materials, CMD, Materials, Metals

Construction Materials: Corrosion, Prevention and Protection Topic Editors: Sergio Lorenzi, Marco Ormellese
Deadline: 1 May 2026

Topic in Analytica, Metals, Molecules, Processes, Separations

Advances in Solvent Extraction Topic Editors: Guoquan Zhang, Weizao Liu
Deadline: 31 May 2026

Topic in Applied Mechanics, Applied Sciences, Materials, Polymers, Solids, Metals

Multi-scale Modeling and Optimisation of Materials Topic Editors: Mustafa Awd, Frank Walther
Deadline: 31 August 2026

More Topics

Conferences

Propose a Conference Collaboration

20–22 April 2026 Coatings 2026: Safe and Sustainable by Design Surface Treatment and Coatings

12–14 October 2026 The 3rd International Online Conference on Metals

29–31 March 2027 [CIC 2027] 5th Coatings and Interfaces Online Conference

More Conferences...

Special Issues

Propose a Special Issue

Special Issue in Metals

Research on Novel Technologies and Theories for Solidification of Metallic Alloys Guest Editors: Junfeng Xu, Changlin Yang
Deadline: 25 January 2026

Special Issue in Metals

Advancements in Metallic Materials for Industrial Applications and Developing Medical Implants Guest Editor: Ildiko Peter
Deadline: 25 January 2026

Special Issue in Metals

Study on the Preparation and Properties of Metal Functional Materials Guest Editor: Weiyi Yang
Deadline: 30 January 2026

Special Issue in Metals

Quality Evaluation of Welding Processes for Metals Guest Editor: Kang Zhou
Deadline: 31 January 2026

More Special Issues

Back to TopTop