Journal of Manufacturing and Materials Processing

18 pages, 14911 KB

Open AccessArticle

A Library of Mechanical Properties of Cu-CuAl Alloys Produced by Wire and Arc Additive Manufacturing

by Filipa G. Cunha, Beatriz Nunes, Valdemar Duarte, Telmo G. Santos and José Xavier

J. Manuf. Mater. Process. 2026, 10(1), 42; https://doi.org/10.3390/jmmp10010042 - 22 Jan 2026

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This study aims to develop a library of Cu-CuAl material compositions and evaluate their mechanical properties. Various compositions are fabricated using Wire Arc Additive Manufacturing (WAAM) with GMAW and GTAW processes. The produced materials are characterised through hardness testing, eddy current measurements, and [...] Read more.

This study aims to develop a library of Cu-CuAl material compositions and evaluate their mechanical properties. Various compositions are fabricated using Wire Arc Additive Manufacturing (WAAM) with GMAW and GTAW processes. The produced materials are characterised through hardness testing, eddy current measurements, and tensile testing supported by Digital Image Correlation (DIC). The hardness analysis reveals that increasing the CuAl content leads to higher hardness values. All compositions display stable and consistent eddy current measurements, except for the alloy with 25% Cu and 75% CuAl, which shows comparatively higher values. The load–displacement curves indicate that higher Cu content enhances ductility, resulting in a lower maximum load. Conversely, a higher CuAl fraction is directly associated with greater ultimate tensile strength. Overall, compositions with higher CuAl content exhibit improved mechanical performance, although they do not reach the levels of commercial materials due to defects inherent to the additive manufacturing process. Full article

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14 pages, 4223 KB

Open AccessArticle

Fabrication of Highly Sensitive Conformal Temperature Sensors on Stainless Steel via Aerosol Jet Printing

by Ziqi Wang, Jun Xu, Yingjie Niu, Yuanyuan Tan, Biqi Yang and Chenglin Yi

J. Manuf. Mater. Process. 2026, 10(1), 41; https://doi.org/10.3390/jmmp10010041 - 21 Jan 2026

Viewed by 673

Abstract

Promoting the development of aerospace vehicles toward structural–functional integration and intelligent sensing is a key strategy for achieving lightweight, high-reliability, and autonomous operation and maintenance of next-generation aircraft. However, traditional external sensors face significant limitations because of their bulky size, installation challenges, and [...] Read more.

Promoting the development of aerospace vehicles toward structural–functional integration and intelligent sensing is a key strategy for achieving lightweight, high-reliability, and autonomous operation and maintenance of next-generation aircraft. However, traditional external sensors face significant limitations because of their bulky size, installation challenges, and incompatibility with aerodynamic surfaces. These issues are particularly pronounced on complex, high-curvature substrates, where achieving conformal bonding is difficult, thus restricting their application in critical components. In this study, aerosol jet printing (AJP) was employed to directly fabricate silver nanoparticle-based temperature sensors with real-time monitoring capabilities on the surface of high-curvature stainless steel sleeves, which serve as typical engineering components. This approach enables the in situ manufacturing of high-precision conformal sensors. Through optimized structural design and thermal treatment, the sensors exhibit reliable temperature sensitivity. Microscopic characterization reveals that the printed sensors possess uniform linewidths and well-defined outlines. After gradient sintering at 250 °C, a dense and continuous conductive path is formed, ensuring strong adhesion to the substrate. Temperature-monitoring results indicate that the sensor exhibits a nearly linear resistance response (R² > 0.999) across a broad detection range of 20–200 °C. It also demonstrates high sensitivity, characterized by a temperature coefficient of resistance (TCR) of 2.15 × 10^−3/°C at 20 °C. In repeated thermal cycling tests, the sensor demonstrates excellent repeatability and stability over 100 cycles, with resistance fluctuations kept within 0.5% and negligible hysteresis observed. These findings confirm the feasibility of using AJP technology to fabricate high-performance conformal sensors on complex surfaces, offering a promising strategy for the development of intelligent structural components in next-generation aerospace engineering. Full article

(This article belongs to the Special Issue 3D Micro/Nano Printing Technologies and Advanced Materials)

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42 pages, 3294 KB

Open AccessReview

Fusion Welding Processes Parameter Optimization for Critical Piping Systems: A Comprehensive Review

by Mohammad Sohel, Vishal S. Sharma and Aravinthan Arumugam

J. Manuf. Mater. Process. 2026, 10(1), 40; https://doi.org/10.3390/jmmp10010040 - 21 Jan 2026

Viewed by 1674

Abstract

Weld quality plays a critical role in ensuring the structural integrity and long-term performance of critical piping systems used across petrochemical, oil and gas, marine, and healthcare sectors. Although gas tungsten arc welding, shielded metal arc welding, and gas metal arc welding are [...] Read more.

Weld quality plays a critical role in ensuring the structural integrity and long-term performance of critical piping systems used across petrochemical, oil and gas, marine, and healthcare sectors. Although gas tungsten arc welding, shielded metal arc welding, and gas metal arc welding are widely applied in pipe fabrication, existing studies often examine these processes independently and provide limited insight into the comparative influence of process parameters on weld morphology, microstructure, and mechanical performance. This review consolidates findings from recent research to evaluate how welding current, arc voltage, heat input, travel speed, shielding gas composition, and joint preparation interact to affect weld bead geometry, heat-affected zone evolution, tensile properties, hardness, and overall weld integrity in piping systems. The primary objective of this review is to critically compare fusion welding process parameter optimization strategies and to identify unresolved challenges in achieving controlled weld root geometry for high-integrity piping applications. Recent industrial failure investigations, particularly in ethylene oxide service piping, further underscore the importance of weld root control. Several documented leak events were traced to excessive root protrusion and inadequate interpretation of non-destructive testing data, where elevated reinforcement disrupted internal flow and promoted turbulence-induced degradation. These recurring issues highlight a broader industry challenge and strengthen the need for improved root-height optimization in critical piping applications. A significant research gap is identified in the limited optimization of weld root reinforcement, particularly in gas tungsten arc welding processes, where most reported studies document root heights exceeding 3 mm. Achieving a root height below 2 mm, which is an important requirement for reducing flow-induced turbulence and meeting industry acceptance criteria, remains insufficiently addressed. This review highlights this gap and outlines future research opportunities involving advanced parameter optimization and improved process monitoring techniques. The synthesis presented here provides a comprehensive reference for enhancing weld quality in critical piping systems and establishes a pathway for next-generation welding strategies aimed at producing high-integrity weld joints compliant with the American Society of Mechanical Engineers B31.3 requirements. Full article

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21 pages, 5844 KB

Open AccessArticle

Design and Material Characterisation of Additively Manufactured Polymer Scaffolds for Medical Devices

by Aidan Pereira, Amirpasha Moetazedian, Martin J. Taylor, Frances E. Longbottom, Heba Ghazal, Jie Han and Bin Zhang

J. Manuf. Mater. Process. 2026, 10(1), 39; https://doi.org/10.3390/jmmp10010039 - 21 Jan 2026

Viewed by 1138

Abstract

Additive manufacturing has been adopted in several industries including the medical field to develop new personalised medical implants including tissue engineering scaffolds. Custom patient-specific scaffolds can be additively manufactured to speed up the wound healing process. The aim of this study was to [...] Read more.

Additive manufacturing has been adopted in several industries including the medical field to develop new personalised medical implants including tissue engineering scaffolds. Custom patient-specific scaffolds can be additively manufactured to speed up the wound healing process. The aim of this study was to design, fabricate, and evaluate a range of materials and scaffold architectures for 3D-printed wound dressings intended for soft tissue applications, such as skin repair. Multiple biocompatible polymers, including polylactic acid (PLA), polyvinyl alcohol (PVA), butenediol vinyl alcohol copolymer (BVOH), and polycaprolactone (PCL), were fabricated using a material extrusion additive manufacturing technique. Eight scaffolds, five with circular designs (knee meniscus angled (KMA), knee meniscus stacked (KMS), circle dense centre (CDC), circle dense edge (CDE), and circle no gradient (CNG)), and three square scaffolds (square dense centre (SDC), square dense edge (SDE), and square no gradient (SNG), with varying pore widths and gradient distributions) were designed using an open-source custom toolpath generator to enable precise control over scaffold architecture. An in vitro degradation study in phosphate-buffered saline demonstrated that PLA exhibited the greatest material stability, indicating minimal degradation under the tested conditions. In comparison, PVA showed improved performance relative to BVOH, as it was capable of absorbing a greater volume of exudate fluid and remained structurally intact for a longer duration, requiring up to 60 min to fully dissolve. Tensile testing of PLA scaffolds further revealed that designs with increased porosity towards the centre exhibited superior mechanical performance. The strongest scaffold design exhibited a Young’s modulus of 1060.67 ± 16.22 MPa and withstood a maximum tensile stress of 21.89 ± 0.81 MPa before fracture, while maintaining a porosity of approximately 52.37%. This demonstrates a favourable balance between mechanical strength and porosity that mimics key properties of engineered tissues such as the meniscus. Overall, these findings highlight the potential of 3D-printed, patient-specific scaffolds to enhance the effectiveness and customisation of tissue engineering treatments, such as meniscus repair, offering a promising approach for next-generation regenerative applications. Full article

(This article belongs to the Special Issue Recent Advances in 3D Printing Technologies in Bioengineering with Selected Papers from the 29th Congress of the European Society of Biomechanics (ESB 2024))

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31 pages, 4237 KB

Open AccessArticle

Cutting Force Mechanisms in Drilling 90MnCrV8 Tool Steel: ANOVA and Theoretical Insights

by Jaroslava Fulemová, Josef Sklenička, Jan Hnátík, Miroslav Gombár, Jindřich Sýkora, Michal Povolný and Adam Lukáš

J. Manuf. Mater. Process. 2026, 10(1), 38; https://doi.org/10.3390/jmmp10010038 - 20 Jan 2026

Viewed by 508

Abstract

This study investigates the influence of tool geometry and cutting parameters on thrust forces and process stability during the drilling of 90MnCrV8, a hard and wear-resistant tool steel. The objective was to identify the dominant and interactive effects of feed per revolution ( [...] Read more.

This study investigates the influence of tool geometry and cutting parameters on thrust forces and process stability during the drilling of 90MnCrV8, a hard and wear-resistant tool steel. The objective was to identify the dominant and interactive effects of feed per revolution (f_rev), nominal tool diameter (D), cutting speed (v_c), and geometry angles (ε_r, α_o, ω_r) on the thrust force (F_f). Experimental data were evaluated using analysis of variance (ANOVA) to determine statistical significance and effect size (η²), supported by theoretical models by Kienzle, Merchant, Oxley and Zorev to explain observed physical trends. Feed per revolution had the most decisive influence on thrust force (η² = 0.690; p < 0.001), followed by tool diameter (D; η² = 0.188). Geometric parameters showed secondary yet significant effects, mainly on stress distribution and chip evacuation. The interaction between D and f_rev produced a multiplicative force increase, while the combination of f_rev and helix angle (ω_r) reduced friction at higher feeds. Cutting speed had a minor effect (η² = 0.007), suggesting limited thermal softening. The findings confirm that drilling hard steels is primarily governed by the energy of plastic deformation. Full article

(This article belongs to the Special Issue Advanced Design, Manufacturing, and Applications of Precision Machine Tools)

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16 pages, 2761 KB

Open AccessArticle

Sustainability Assessment of Machining Processes in Turbine Disk Production: From Data Acquisition to Digital Anchoring in the PCF AAS Submodel

by Marc Ubach, David Ehrenberg, Viktor Rudel, Stefan Schröder and Thomas Bergs

J. Manuf. Mater. Process. 2026, 10(1), 37; https://doi.org/10.3390/jmmp10010037 - 20 Jan 2026

Viewed by 481

Abstract

Over the past decades, global air traffic has increased continuously, with passenger kilometers roughly doubling every fifteen to twenty years, and this trend is estimated to continue, with some adjustments due to COVID-19 impact. In response to the resulting environmental challenges, the European [...] Read more.

Over the past decades, global air traffic has increased continuously, with passenger kilometers roughly doubling every fifteen to twenty years, and this trend is estimated to continue, with some adjustments due to COVID-19 impact. In response to the resulting environmental challenges, the European initiatives Flightpath 2050 and Clean Sky serve as central drivers of technological development aimed at achieving ambitious sustainability goals. Flightpath 2050 targets, relative to a reference engine from the year 2000, include a 75% reduction in CO₂ emissions per passenger kilometer, a 90% reduction in NO_x emissions, and a 65% reduction in noise emissions. These objectives highlight the urgent need for emission reduction strategies across all manufacturing domains, including turbine component production. This study evaluates the environmental impacts of the preturning and roughing operations employed in turbine disk production. The analysis focuses on these specific processes rather than the entire product, as the approach of process-level Life Cycle Assessments (LCA) are more universally applicable across different products, and their systematic combination can ultimately form a comprehensive product-level LCA. Operational data, such as energy usage, cooling lubricants, and compressed air, were gathered and processed from the equipment involved in manufacturing. The collected data were analyzed and modeled in Spheras life cycle assessment software LCA for Experts (version 10.9.0.20) to quantify the environmental effects of each process. The findings of the current research emphasize notable patterns of resource utilization and their respective environmental impacts. Furthermore, the Industrial Digital Twin Association (IDTA) Product Carbon Footprint (PCF) template was utilized to present the findings in a standardized manner, enabling effective data transfer between stakeholders. The results demonstrate the critical need to leverage machine data for sustainability analysis, providing inputs for industry practice enhancement and progress toward better environmental performance. Full article

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15 pages, 2192 KB

Open AccessArticle

Corrosion Behaviour and Residual Stress State of Laser-Welded Ti6Al4V/AA7075 Joints with a Ag Interlayer

by Asim Iltaf, Narges Ghafouri, Noureddine Barka, Shayan Dehghan and Rafiq Ahmad

J. Manuf. Mater. Process. 2026, 10(1), 36; https://doi.org/10.3390/jmmp10010036 - 19 Jan 2026

Cited by 1 | Viewed by 579

Abstract

In this study, the corrosion performance and near-surface residual stress state of laser-welded Ti6Al4V/AA7075 dissimilar joints produced with a silver (Ag) interlayer are investigated. Potentiodynamic polarization, cyclic polarization, and electrochemical impedance spectroscopy (EIS) were carried out on Ti6Al4V base alloy (BA), AA7075 BA, [...] Read more.

In this study, the corrosion performance and near-surface residual stress state of laser-welded Ti6Al4V/AA7075 dissimilar joints produced with a silver (Ag) interlayer are investigated. Potentiodynamic polarization, cyclic polarization, and electrochemical impedance spectroscopy (EIS) were carried out on Ti6Al4V base alloy (BA), AA7075 BA, and the fusion zone (FZ) containing the Ag interlayer. The Ag interlayer FZ exhibits an intermediate but clearly improved corrosion response compared with AA7075 BA, with a corrosion potential E_corr ≈ 0.260 V, corrosion current density i_corr ≈ 4.55 × 10⁻⁶ A cm⁻², and polarization resistance Rp ≈ 7.08 kΩ cm². EIS fitting further indicates a charge-transfer resistance of R_ct ≈ 3.7 × 10⁴ Ω cm² and a moderate oxide film resistance, consistent with a more stable electrochemical interface than AA7075 BA in 3.5 wt.% NaCl. Additionally, the residual stress measurements reveal that the Ag interlayer joint develops a predominantly compressive residual stress field on both sides of the weld. This compressive state is beneficial for delaying pit-to-crack transition and enhancing durability under corrosive loading. A brief comparison with our previously published Ti6Al4V/AA7075 welds produced using a Cu interlayer under the same laser welding parameters and joint configuration as the present study shows that the Ag interlayer provides more favourable compressive residual stresses and a more noble, higher-resistance electrochemical response. Full article

(This article belongs to the Special Issue Advanced Laser-Assisted Manufacturing Processes)

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15 pages, 6954 KB

Open AccessArticle

The Influence of Surface State and Weldment on the Corrosion Behavior of X65 Steel in Seawater and Production Water Environments

by Pei Li, Yulong Wei, Qingjian Liu, Yvcan Liu and Zhenhao Sun

J. Manuf. Mater. Process. 2026, 10(1), 35; https://doi.org/10.3390/jmmp10010035 - 14 Jan 2026

Viewed by 654

Abstract

In this study, the service behavior of an X65 oil and gas pipeline in seawater and production water environments was simulated by a corrosion experiment, and the influence of surface treatment (polishing and scratching) on its corrosion behavior was systematically analyzed. The corrosion [...] Read more.

In this study, the service behavior of an X65 oil and gas pipeline in seawater and production water environments was simulated by a corrosion experiment, and the influence of surface treatment (polishing and scratching) on its corrosion behavior was systematically analyzed. The corrosion resistance of the material was evaluated by means of scanning electron microscopy (SEM), an electrochemical test, and uniform corrosion rate calculations. The results show that the corrosion degree of X65 steel in an oilfield production water environment is significantly higher than that in a seawater environment. The uniform corrosion rate of the welding area is as high as 1.05 mm/y, which is more sensitive than that of the matrix material. The surface treatment has a significant effect on the corrosion behavior. The polishing treatment reduces the corrosion current density of the matrix material from 472.44 μA/cm² to 313.10 μA/cm², and the polarization resistance increases to 14.07 kΩ·cm², which effectively improves its corrosion resistance. The scratch treatment significantly reduces the corrosion resistance of the material, and the corrosion current density of the welding area at the scratch site is as high as 313.00 μA/cm², even more than that of the untreated matrix material. The study further points out that the scratches and welding areas generated during the pipeline cleaning process will significantly aggravate the tendency of local corrosion and pitting corrosion due to their microstructure heterogeneity. This study provides a clear theoretical basis and engineering guidance for the anti-corrosion design and maintenance of offshore oil and gas pipelines in complex water quality environments. Full article

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17 pages, 5147 KB

Open AccessArticle

Microscopic Thermal Behavior of Iron-Mediated Platinum Group Metal Capture from Spent Automotive Catalysts

by Xiaoping Zhu, Ke Shi, Chuan Liu, Yige Yang, Jinrong Zhao, Xiaolong Sai, Shaobo Wen and Shuchen Sun

J. Manuf. Mater. Process. 2026, 10(1), 34; https://doi.org/10.3390/jmmp10010034 - 13 Jan 2026

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Abstract

This research investigates the micro-mechanisms and process control associated with the recovery of platinum group metals (PGMs) from spent automotive catalysts (SACs) through iron capturing. High-temperature smelting experiments, complemented by SEM-EDS and XRD analyses, demonstrate that PGMs spontaneously migrate from the slag phase [...] Read more.

This research investigates the micro-mechanisms and process control associated with the recovery of platinum group metals (PGMs) from spent automotive catalysts (SACs) through iron capturing. High-temperature smelting experiments, complemented by SEM-EDS and XRD analyses, demonstrate that PGMs spontaneously migrate from the slag phase to the iron phase, driven by interfacial energy, where they are captured to form alloy droplets with a PGM content exceeding 4 wt.%. The composite flux (CaO/H₃BO₃) markedly diminishes slag viscosity and enhances the density differential between slag and metal. This facilitates the aggregation, sedimentation, and separation of alloy droplets in accordance with Stokes’ law, thereby lowering the effective capture temperature from 1700 °C to 1500 °C and reducing energy consumption. Additionally, the flux inhibits the formation of detrimental Fe-Si alloys. PGMs form substitutional solid solutions that are uniformly dispersed within the iron matrix. This study provides both the theoretical and technical foundations necessary for the development of efficient, low-energy processes aimed at capturing and recovering Fe-PGMs alloys. Full article

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19 pages, 5806 KB

Open AccessArticle

Ballistic Failure Analysis of Hybrid Natural Fiber/UHMWPE-Reinforced Composite Plates Using Experimental and Finite Element Methods

by Eduardo Magdaluyo, Jr., Ariel Jorge Payot, Lorenzo Matilac and Denisse Jonel Pavia

J. Manuf. Mater. Process. 2026, 10(1), 33; https://doi.org/10.3390/jmmp10010033 - 13 Jan 2026

Viewed by 1179

Abstract

This study evaluated the ballistic performance and failure mechanisms of epoxy-based hybrid laminates reinforced with abaca/UHMWPE and pineapple leaf fiber (PALF)/UHMWPE fabrics fabricated by using vacuum-assisted hand lay-up. Ballistic tests utilized 9 mm full metal jacket (FMJ) rounds (~426 m/s impact velocity) under [...] Read more.

This study evaluated the ballistic performance and failure mechanisms of epoxy-based hybrid laminates reinforced with abaca/UHMWPE and pineapple leaf fiber (PALF)/UHMWPE fabrics fabricated by using vacuum-assisted hand lay-up. Ballistic tests utilized 9 mm full metal jacket (FMJ) rounds (~426 m/s impact velocity) under NIJ Standard Level IIIA conditions (44 mm maximum allowable BFS). This experimental test was complemented by finite element analysis (FEA) incorporating an energy-based bilinear fracture criterion to simulate matrix cracking and fiber pull-out. The results showed that abaca/UHMWPE composites exhibited lower backface signature (BFS) and depth of penetration (DOP) values (~23 mm vs. ~42 mm BFS; ~7 mm vs. ~9 mm DOP) than PALF/UHMWPE counterparts, reflecting superior interfacial adhesion and more ductile failure modes. Accelerated weathering produced matrix microcracking and delamination in both systems, reducing overall ballistic resistance. Scanning electron microscopy confirmed improved fiber–matrix bonding in abaca composites and interfacial voids in PALF laminates. The FEA results reproduced major failure modes, such as delamination, fiber–matrix debonding, and petaling, and identified stress concentration zones that agreed with experimental observations, though the extent of delamination was slightly underpredicted. Overall, the study demonstrated that abaca/UHMWPE hybridcomposites offer enhanced ballistic performance and durability compared with PALF/UHMWPE laminates, supporting their potential as sustainable alternatives for lightweight protective applications. Full article

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16 pages, 4957 KB

Open AccessArticle

A Comparative Analysis of the Weld Pools Created with DC Single-, DC Double-, and PC Double-Electrode Configurations in Autogenous GTAW

by Shahid Parvez

J. Manuf. Mater. Process. 2026, 10(1), 32; https://doi.org/10.3390/jmmp10010032 - 13 Jan 2026

Viewed by 913

Abstract

Three different Gas Tungsten Arc Welding methods—DC single electrode, DC double electrode, and PC double electrode—were analyzed using SS304 steel as the base material. Numerical models were developed to simulate the arc plasmas and calculate heat flux, current density, and wall shear stress [...] Read more.

Three different Gas Tungsten Arc Welding methods—DC single electrode, DC double electrode, and PC double electrode—were analyzed using SS304 steel as the base material. Numerical models were developed to simulate the arc plasmas and calculate heat flux, current density, and wall shear stress on the surface of the workpiece. These data were used as input to simulate the weld pools across all three configurations. Experimental validation showed a good agreement with the numerical results. In the double-electrode setup, electromagnetic interaction caused the arcs to deflect, resulting in an 8% reduction in the maximum heat flux and a 4% decrease in the maximum current density. Marangoni stress had a notable effect on the weld pool shape, creating a -shaped pool with the stationary single-electrode setup, whereas the double-electrode setup produced a -shaped pool after 2 s. In the moving weld pool configurations, the sizes of the pools were maximum at the trailing electrodes. The pool was 1.7 mm deep and 5.6 mm wide in DC double- and 1.4 mm deep and 5.4 mm wide in PC double-electrode configurations. The pool depth and width were only 1.0 mm and 4.2 mm when a DC single-electrode setup was used. Comparing the three methods, the DC double-electrode setup produced the largest pool size. The findings of this research offer guidance for enhancing different arc settings and electrode arrangements to attain the intended welding quality and performance. Full article

(This article belongs to the Special Issue Innovative Approaches in Metal Forming and Joining Technologies)

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27 pages, 3406 KB

Open AccessReview

Design Strategies for Enhanced Performance of 3D-Printed Microneedle Arrays

by Mahmood Razzaghi and Hamid Reza Bakhsheshi-Rad

J. Manuf. Mater. Process. 2026, 10(1), 31; https://doi.org/10.3390/jmmp10010031 - 12 Jan 2026

Cited by 2 | Viewed by 1092

Abstract

Three-dimensional (3D) printing has transformed the development of microneedle arrays (MNAs) by enabling exceptional control over their geometry, distribution, materials, and functionality in a single-step, customizable process. This review represents a design-centric framework that organizes recent advancements in four interconnected levers: (i) individual [...] Read more.

Three-dimensional (3D) printing has transformed the development of microneedle arrays (MNAs) by enabling exceptional control over their geometry, distribution, materials, and functionality in a single-step, customizable process. This review represents a design-centric framework that organizes recent advancements in four interconnected levers: (i) individual microneedle (MN) geometry and size; (ii) patch-level MN distribution and multi-array architectures; (iii) computer-aided design (CAD), finite element analysis (FEA), computational fluid dynamics (CFD), and artificial intelligence/machine learning (AI/ML)-driven optimization; and (iv) manufacturing constraints and emerging solutions for scalability and reproducibility. Outcomes show that small changes in the radius of the MN’s tip, the MN’s aspect ratio, the MN’s internal lattice architecture, and the spacing of the array can dramatically influence their insertion force, mechanical reliability, payload capacity, and therapeutic coverage. Now, digital tools can bridge the design and experimental outcomes, while novel morphologies, hybrid materials, and theranostic integrations are expanding the clinical potential of MNs. The remaining challenges, resolution-versus-throughput trade-offs, biocompatibility, batch-to-batch consistency, and lack of testing standardization are examined alongside promising directions in high-throughput 3D printing, stimuli-responsive materials, and closed-loop systems. Finally, rational, model-guided design strategies are positioning 3D-printed MNAs as versatile platforms for painless, patient-specific drug delivery, diagnostics, and personalized medicine. Full article

(This article belongs to the Special Issue Advances in 3D Printing Technologies: Materials, Processes, and Applications, 2nd Edition)

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29 pages, 4522 KB

Open AccessArticle

An Experimental–Numerical Framework for Springback Prediction and Angle Compensation in Air Bending with Additively Manufactured Polymer Tools

by Vesna Mandic, Marko Delic, Dragan Adamovic, Dusan Arsic, Nada Ratkovic, Djordje Ivkovic and Andjelka Ilic

J. Manuf. Mater. Process. 2026, 10(1), 30; https://doi.org/10.3390/jmmp10010030 - 11 Jan 2026

Viewed by 698

Abstract

Additive manufacturing of polymer tools represents a promising alternative to conventional steel tooling for low-force and low-volume sheet metal air bending. However, accurate prediction of sheet springback and the resulting deviation of the bending angle after elastic unloading remains a major challenge. This [...] Read more.

Additive manufacturing of polymer tools represents a promising alternative to conventional steel tooling for low-force and low-volume sheet metal air bending. However, accurate prediction of sheet springback and the resulting deviation of the bending angle after elastic unloading remains a major challenge. This study presents an integrated experimental–numerical framework for the analysis of air bending with additively manufactured polymer tools, with emphasis on material characterization, springback prediction, and tool angle compensation. The methodology combines uniaxial tensile testing, controlled air-bending experiments, finite element modelling with rigid and deformable tools, and optical 3D scanning for angle measurement. Low-carbon steel DC04 sheets were modeled using an elastoplastic constitutive law, while additively manufactured ABS tools were described by experimentally calibrated material models. Numerical simulations were performed over a range of forming forces to evaluate springback behavior and elastic tool deformation. The results show very good agreement between experiments and simulations. Deviations in bending angle were below 1.5% for metallic tools and below 0.5% for springback compensation, with the smallest discrepancy obtained using a two-dimensional model with deformable tools. Experimental validation with ABS tools confirmed bending accuracy within ±1°. The proposed framework provides a reliable basis for springback prediction and rational design of additively manufactured polymer tools for air-bending applications. Full article

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30 pages, 35300 KB

Open AccessArticle

Mechanical Characterization and Numerical Modeling of 316 Stainless Steel Specimens Fabricated Using SLM

by Ana-Gabriela Badea, Stefan Tabacu, Alina-Ionela Aparaschivei, Denis Negrea, Sorin Moga and Catalin Ducu

J. Manuf. Mater. Process. 2026, 10(1), 29; https://doi.org/10.3390/jmmp10010029 - 10 Jan 2026

Viewed by 809

Abstract

This study examines the influence of build orientation on the mechanical behavior of 316 stainless steel components fabricated by selective laser melting (SLM). Additively manufactured tensile specimens produced in different build orientations were experimentally analyzed and compared with reference specimens obtained from conventionally [...] Read more.

This study examines the influence of build orientation on the mechanical behavior of 316 stainless steel components fabricated by selective laser melting (SLM). Additively manufactured tensile specimens produced in different build orientations were experimentally analyzed and compared with reference specimens obtained from conventionally hot-rolled material and laser-cut to identical geometries. Uniaxial tensile testing combined with digital image correlation (DIC) was employed to evaluate the mechanical response and full-field strain evolution. Microstructural features were investigated using scanning electron microscopy (SEM), while phase composition was assessed by X-ray diffraction (XRD). The results reveal a pronounced orientation-dependent mechanical anisotropy in the SLM specimens, reflected in variations in yield strength, ultimate tensile strength, and ductility. Specimens loaded perpendicular to the build directions exhibited higher strength but reduced ductility compared to those loaded parallel to the build direction, whereas the rolled material showed a more isotropic mechanical response. Although the XYZ and XZY samples feature similar deposition patterns, the XRD analysis revealed a the existence of a

[220]

texture. Thus, the mechanical performances of XZY specimens are about

10 %

lower compared to XYZ printed samples. The stress maximum–strain curves were extrapolated from the true data using the Swift model. The section dedicated to numerical modeling includes a failure model based on the traixility. The numerical models were validated for the range

η \in [0.33 \dots 0.45]

specific to uniaxial tension. Fractographic observations further confirmed the correlation between build orientation, microstructural features, and fracture behavior. The present study provides a multiscale experimental framework linking processing conditions, microstructure, and mechanical response in additively manufactured stainless steel. Full article

(This article belongs to the Special Issue Design and Manufacturing of Lightweight Materials Process and Structures)

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42 pages, 2357 KB

Open AccessReview

Advances in Materials and Manufacturing for Scalable and Decentralized Green Hydrogen Production Systems

by Gabriella Stefánia Szabó, Florina-Ambrozia Coteț, Sára Ferenci and Loránd Szabó

J. Manuf. Mater. Process. 2026, 10(1), 28; https://doi.org/10.3390/jmmp10010028 - 9 Jan 2026

Cited by 7 | Viewed by 2037

Abstract

The expansion of green hydrogen requires technologies that are both manufacturable at a GW-to-TW power scale and adaptable for decentralized, renewable-driven energy systems. Recent advances in proton exchange membrane, alkaline, and solid oxide electrolysis reveal persistent bottlenecks in catalysts, membranes, porous transport layers, [...] Read more.

The expansion of green hydrogen requires technologies that are both manufacturable at a GW-to-TW power scale and adaptable for decentralized, renewable-driven energy systems. Recent advances in proton exchange membrane, alkaline, and solid oxide electrolysis reveal persistent bottlenecks in catalysts, membranes, porous transport layers, bipolar plates, sealing, and high-temperature ceramics. Emerging fabrication strategies, including roll-to-roll coating, spatial atomic layer deposition, digital-twin-based quality assurance, automated stack assembly, and circular material recovery, enable high-yield, low-variance production compatible with multi-GW power plants. At the same time, these developments support decentralized hydrogen systems that demand compact, dynamically operated, and material-efficient electrolyzers integrated with local renewable generation. The analysis underscores the need to jointly optimize material durability, manufacturing precision, and system-level controllability to ensure reliable and cost-effective hydrogen supply. This paper outlines a convergent approach that connects critical-material reduction, high-throughput manufacturing, a digitalized balance of plant, and circularity with distributed energy architectures and large-scale industrial deployment. Full article

(This article belongs to the Special Issue Recent Developments in Materials Processing for Modern Applications: Advancements and Challenges)

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27 pages, 4899 KB

Open AccessReview

Advances in Texturing of Polycrystalline Diamond Tools in Cutting Hard-to-Cut Materials

by Sergey N. Grigoriev, Anna A. Okunkova, Marina A. Volosova, Khaled Hamdy and Alexander S. Metel

J. Manuf. Mater. Process. 2026, 10(1), 27; https://doi.org/10.3390/jmmp10010027 - 9 Jan 2026

Viewed by 1214

Abstract

The operational ability of a unit or mechanism depends mainly on the quality of the mechanically produced working surfaces. Many materials can be assigned to a group of hard-to-cut materials that includes titanium- and aluminum-based alloys, a new class of heat-resistant alloys, SiCp/Al [...] Read more.

The operational ability of a unit or mechanism depends mainly on the quality of the mechanically produced working surfaces. Many materials can be assigned to a group of hard-to-cut materials that includes titanium- and aluminum-based alloys, a new class of heat-resistant alloys, SiCp/Al composites, hard alloys, and other alloys. The difficulties in their machining are related not only to the high temperatures achieved on the contact pads under mechanical load and the extreme cutting conditions but also to the properties of those materials, which affect the adhesion of the chip to the tool faces, hindering chip flow. One of the possible solutions to reduce those effects and improve the operational life of the tool, and as a consequence, the final quality of the working surface of the unit, is texturing the rake face of the tool with microgrooves or nanogrooves, microholes or nanoholes (pits, dimples), micronodes, cross-chevron textures, and other microtextures, the depth of which is in the range of 3.0–200.0 µm. This review is addressed at systematizing the data obtained on micro- and nanotexturing of PCD tools for cutting hard-to-cut materials by different techniques (fiber laser graving, femto- and nanosecond laser, electrical discharge machining, fused ion beam), additionally subjected to fluorination and dip- and drop-based coatings, and the effect created by the use of the textured PCD tool on the machined surface. Full article

(This article belongs to the Special Issue Recent Developments in Materials Processing for Modern Applications: Advancements and Challenges)

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13 pages, 2799 KB

Open AccessArticle

Effects of Binder Saturation and Drying Time in Binder Jetting Additive Manufacturing on Dimensional Deviation and Density of SiC Green Parts

by Mostafa Meraj Pasha, Zhijian Pei, Md Shakil Arman and Stephen Kachur

J. Manuf. Mater. Process. 2026, 10(1), 26; https://doi.org/10.3390/jmmp10010026 - 9 Jan 2026

Viewed by 752

Abstract

Binder jetting additive manufacturing (BJAM) offers an effective approach for fabricating silicon carbide (SiC) parts with complex geometries; however, part quality is strongly influenced by process variables. Binder saturation and drying time are key process variables in BJAM, yet their individual influences on [...] Read more.

Binder jetting additive manufacturing (BJAM) offers an effective approach for fabricating silicon carbide (SiC) parts with complex geometries; however, part quality is strongly influenced by process variables. Binder saturation and drying time are key process variables in BJAM, yet their individual influences on the density and dimensional deviation of SiC green parts remain underexplored. To address this gap, this study systematically investigates the effects of binder saturation and drying time on the dimensional deviation and density of SiC green parts by evaluating four binder saturation levels (60%, 80%, 100%, and 120%) and three drying times (15, 30, and 45 s). The results show that increasing binder saturation reduces green part density and increases dimensional deviation, whereas increasing drying time improves density and reduces dimensional deviation. Excessive drying, however, causes severe warpage, preventing the fabrication of dimensionally accurate parts. These findings highlight the need to optimize binder saturation and drying time to improve the density of printed parts while minimizing dimensional deviation. Full article

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22 pages, 62404 KB

Open AccessArticle

Enhancement of Microstructure, Tensile and Fatigue Performance of EN AW-1050 by Wire-Based Friction Stir Additive Manufacturing

by Stefan Donaubauer, Raphael Schmid, Stefan Weihe and Martin Werz

J. Manuf. Mater. Process. 2026, 10(1), 25; https://doi.org/10.3390/jmmp10010025 - 8 Jan 2026

Cited by 1 | Viewed by 1129

Abstract

Additive manufacturing (AM) of aluminium by solid-state routes offers a promising pathway to overcome the limitations of fusion-based processes, such as porosity and hot cracking. This study investigates the potential of wire-based friction stir additive manufacturing (W-FSAM) as an innovative solid-state process. A [...] Read more.

Additive manufacturing (AM) of aluminium by solid-state routes offers a promising pathway to overcome the limitations of fusion-based processes, such as porosity and hot cracking. This study investigates the potential of wire-based friction stir additive manufacturing (W-FSAM) as an innovative solid-state process. A test specimen made of EN AW-1050 was fabricated and characterised using mechanical testing as well as optical and electron microscopy. Microstructural characterisation revealed a fully consolidated, pore-free build with fine equiaxed grains and partial dynamic recrystallisation (DRX). The average grain size decreased from 13.4 µm near the substrate to 9.7 µm at the top, reflecting the variation in cumulative thermal exposure along the build height. A homogeneous hardness distribution (21.2 HV) and smooth interlayer interfaces were observed. Tensile tests in the travel direction yielded an ultimate tensile strength of approximately 85 MPa and an elongation exceeding 60%, while high-cycle fatigue tests demonstrated a fatigue strength of about 30 MPa at

2 \times 10^{6}

cycles (

R = 0.1

) with ductile fracture features. The results confirm that W-FSAM enables the production of fine-grained, defect-free CP-Al structures whose mechanical properties, in terms of strength and ductility, exceed those of the reference material. Thus, W-FSAM represents a promising solid-state additive manufacturing route for the production of high-performance CP-Al components. Full article

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15 pages, 3635 KB

Open AccessArticle

In Situ Extrusion Processing of Treated and Untreated Pineapple Leaf Fibre-Reinforced PLA Composites for Improved Impact Performance

by Wei Jie Ng, Mun Kou Lai, Ching Hao Lee and Tze Chuen Yap

J. Manuf. Mater. Process. 2026, 10(1), 24; https://doi.org/10.3390/jmmp10010024 - 8 Jan 2026

Viewed by 841

Abstract

Material extrusion (MEX) 3D-printed parts are primarily used for prototyping rather than functional components due to lower mechanical strength. To address this limitation and promote sustainability, current work explores the reinforcement of plant-based polylactic acid (PLA) with pineapple leaf fibre (PALF). An in [...] Read more.

Material extrusion (MEX) 3D-printed parts are primarily used for prototyping rather than functional components due to lower mechanical strength. To address this limitation and promote sustainability, current work explores the reinforcement of plant-based polylactic acid (PLA) with pineapple leaf fibre (PALF). An in situ approach was proposed to embed continuous PALF within the middle layer of a 3D-printed component during the MEX process. An experimental investigation was conducted to evaluate the impact performance of composites produced via this new fabrication method. To optimize the fibre–matrix interface, an alkaline treatment was applied to the natural fibre, enhancing interfacial adhesion. Neat PLA, along with two types of PALF-reinforced PLA composite, were printed with both single-strand and three-strand fibre configurations. Fracture surfaces were analyzed under a digital microscope and a scanning electron microscope (SEM) to correlate morphological characteristics with the impact strength. The results showed that the impact strength of the three-strand treated PALF-PLA composite (3 PALF-PLA) surpassed that of neat PLA by 2.71% due to reduced porosity. In contrast, the one-strand PALF-PLA composites exhibited lower performance compared to neat PLA due to the presence of the fibre gap caused by the mid-print pause. Treated fibres consistently outperformed untreated ones due to their rougher surface morphology resulting from alkaline treatment. The results demonstrate that the combination of alkaline treatment and continuous fibre reinforcement significantly enhances energy absorption of 3D-printed MEX parts and offers a sustainable pathway for 3D-printed MEX parts. Full article

(This article belongs to the Special Issue Innovative and Sustainable Advances in Polymer Composites for Additive Manufacturing: Processing, Microstructure, Machining, and Mechanical Properties)

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24 pages, 4217 KB

Open AccessArticle

Foundations for Future Prosthetics: Combining Rheology, 3D Printing, and Sensors

by Salman Pervaiz, Krittika Goyal, Jun Han Bae and Ahasan Habib

J. Manuf. Mater. Process. 2026, 10(1), 23; https://doi.org/10.3390/jmmp10010023 - 8 Jan 2026

Viewed by 954

Abstract

The rising global demand for prosthetic limbs, driven by approximately 185,000 amputations annually in the United States, underscores the need for innovative and cost-efficient solutions. This study explores the integration of hybrid materials, advanced 3D printing techniques, and smart sensing technologies to enhance [...] Read more.

The rising global demand for prosthetic limbs, driven by approximately 185,000 amputations annually in the United States, underscores the need for innovative and cost-efficient solutions. This study explores the integration of hybrid materials, advanced 3D printing techniques, and smart sensing technologies to enhance prosthetic finger production. A Taguchi-based design of experiments (DoE) approach using an L09 orthogonal array was employed to systematically evaluate the effects of infill density, infill pattern, and print speed on the tensile behavior of FDM-printed PLA components. Findings reveal that higher infill densities (90%) and hexagonal patterns significantly enhance yield strength, ultimate tensile strength, and stiffness. Additionally, the rheological properties of polydimethylsiloxane (PDMS) were optimized at various temperatures (30–70 °C), characterizing its viscosity, shear-thinning factors, and stress behaviors for 3D bioprinting of flexible sensors. Barium titanate (BaTiO₃) was incorporated into PDMS to fabricate a flexible tactile sensor, achieving reliable open-circuit voltage readings under applied forces. Structural and functional components of the finger prosthesis were fabricated using FDM, stereolithography (SLA), and extrusion-based bioprinting (EBP) and assembled into a functional prototype. This research demonstrates the feasibility of integrating hybrid materials and advanced printing methodologies to create cost-effective, high-performance prosthetic components with enhanced mechanical properties and embedded sensing capabilities. Full article

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16 pages, 5764 KB

Open AccessArticle

Effect of Bonding Pressure and Joint Thickness on the Microstructure and Mechanical Reliability of Sintered Nano-Silver Joints

by Phuoc-Thanh Tran, Quang-Bang Tao, Lahouari Benabou and Ngoc-Anh Nguyen-Thi

J. Manuf. Mater. Process. 2026, 10(1), 22; https://doi.org/10.3390/jmmp10010022 - 8 Jan 2026

Cited by 1 | Viewed by 1747

Abstract

Sintered nano-silver is widely investigated as a die-attach material for next-generation power electronic modules due to its high thermal conductivity, favorable electrical performance, and stability at elevated temperatures. However, how bonding pressure and joint thickness jointly affect densification, interfacial diffusion, and mechanical reliability [...] Read more.

Sintered nano-silver is widely investigated as a die-attach material for next-generation power electronic modules due to its high thermal conductivity, favorable electrical performance, and stability at elevated temperatures. However, how bonding pressure and joint thickness jointly affect densification, interfacial diffusion, and mechanical reliability has not been systematically clarified, especially under the low-pressure conditions required for large-area SiC and GaN devices. In this work, nano-silver lap-shear joints with three bond-line thicknesses (50, 70, and 100 μm) were fabricated under two applied pressures (1.0 and 1.5 MPa) using a controlled sintering fixture. Shear testing and cross-sectional SEM were employed to evaluate the relationships between microstructural evolution and joint integrity. When the bonding pressure was increased from 1.0 to 1.5 MPa, more effective particle rearrangement and reduced pore connectivity were observed, together with improved metallurgical bonding at the Ag–Au interface, leading to a strength increase from 15.3 to 28.2 MPa. Although thicker joints exhibited slightly higher bulk relative density due to greater heat retention and accelerated local sintering, this densification advantage did not lead to improved mechanical performance. Instead, the lower strength of thicker joints is attributed to a narrower Ag–Au interdiffusion region, which limited the formation of continuous load-bearing paths at the interface. Fractographic analyses confirmed that failure occurred predominantly by interfacial delamination rather than cohesive fracture, indicating that the reliability of the joints under low-pressure sintering is governed by the quality of interfacial bonding rather than by overall densification. The experimental results show that, under low-pressure sintering conditions (1.0–1.5 MPa), variations in bonding pressure and bond-line thickness lead to distinct effects on joint performance, with the extent of Ag–Au interfacial interaction playing a key role in determining the mechanical robustness of the joints. Full article

(This article belongs to the Special Issue Innovative Approaches in Metal Forming and Joining Technologies)

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14 pages, 1993 KB

Open AccessArticle

Experimental Investigation into the Influence of Infill Density, Print Pattern, and Built-Up Direction on the Flexural Strength of FFF-Manufactured PLA Components

by Christoph Buss, Fabio Reci, Thomas Hribernig and Stefan Steininger

J. Manuf. Mater. Process. 2026, 10(1), 21; https://doi.org/10.3390/jmmp10010021 - 7 Jan 2026

Cited by 1 | Viewed by 1215

Abstract

This study evaluates the flexural strength of poly lactic acid parts (PLAs) fabricated with fused filament fabrication (FFF) by systematically analyzing the combined effects of infill density, infill pattern, and built-up orientation. Therefore, samples with 10, 30, 50, 70, and 90% infill densities [...] Read more.

This study evaluates the flexural strength of poly lactic acid parts (PLAs) fabricated with fused filament fabrication (FFF) by systematically analyzing the combined effects of infill density, infill pattern, and built-up orientation. Therefore, samples with 10, 30, 50, 70, and 90% infill densities were printed with cubic and triangular patterns in all three possible built-up directions (Cartesian X, Y, Z) and subjected to a standardized three-point bending test according to ISO 178, while printing time was concurrently assessed to quantify trade-offs between mechanical performance and manufacturing efficiency. The results show that a cubic infill with layers transverse to the bending load (Y-direction) offers the highest flexural strength of about 31 MPa for 90% infill density at comparably low printing times. In addition to significantly longer printing times, samples printed in the X-direction achieved the highest flexural strengths across all configurations tested for both infill patterns examined, up to densities of approximately 60%. Full article

(This article belongs to the Special Issue Mechanics and Manufacturing of Advanced Composite Materials and Structures)

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21 pages, 8488 KB

Open AccessArticle

Effect of Peel Ply-Induced Surface Roughness and Wettability on the Adhesive Bonding of GFRP Composites

by Barbara Silva, Paulo Antunes and Braian Uribe

J. Manuf. Mater. Process. 2026, 10(1), 20; https://doi.org/10.3390/jmmp10010020 - 7 Jan 2026

Viewed by 1194

Abstract

Adhesive joint failure remains a critical limitation in the manufacturing of large wind turbine blades, where reliable and reproducible surface preparation methods are required at an industrial scale. This study systematically evaluates the effect of peel ply-induced surface morphology and chemistry on the [...] Read more.

Adhesive joint failure remains a critical limitation in the manufacturing of large wind turbine blades, where reliable and reproducible surface preparation methods are required at an industrial scale. This study systematically evaluates the effect of peel ply-induced surface morphology and chemistry on the adhesion performance of glass fiber-reinforced polymer (GFRP) laminates, explicitly examining the relationship between wettability and bonding strength. Five surface conditions were generated during vacuum-assisted resin infusion using different commercial and proprietary peel plies and a smooth mold surface. Despite significant differences in contact angle and surface energy, lap shear testing revealed no significant relationship between wettability and joint strength. Instead, surface roughness-driven mechanical interlocking and adhesive–substrate compatibility dominated performance. Compared to the smooth mold surface, twill-type peel ply–modified adherends increased shear strength by up to 3.9×, while other commercial types of peel-plies presented strength improvements between 2.7 and 3.3×. More compatible adhesive–polymer resin systems exhibited a combination of cohesive and adhesive failures, with no clear dependence on surface roughness. In contrast, when the adhesive is less compatible with the substrate, surface roughness significantly affects the adhesive response, with adhesive failure predominating. The adhesive application temperature showed no measurable effect for practical industrial use. These findings demonstrate that wettability alone is not a reliable predictor of adhesion performance for this class of substrates and confirm peel ply surface modification as a robust, scalable solution for industrial wind blade bonding. Full article

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17 pages, 5165 KB

Open AccessArticle

Development and Characterization of Compression-Molded Chitosan Composite Films Reinforced with Silica and Titania Fillers

by Bhuvaneswari Koti, Vuong Do, Yanika Schneider and Vimal Viswanathan

J. Manuf. Mater. Process. 2026, 10(1), 19; https://doi.org/10.3390/jmmp10010019 - 6 Jan 2026

Viewed by 909

Abstract

This study investigates the development of biodegradable chitosan-based films as a sustainable alternative to conventional non-biodegradable food packaging materials. Chitosan, a naturally occurring polymer, possesses inherent film-forming ability and biodegradability; however, its limited mechanical and thermal properties constrain its practical applications. In this [...] Read more.

This study investigates the development of biodegradable chitosan-based films as a sustainable alternative to conventional non-biodegradable food packaging materials. Chitosan, a naturally occurring polymer, possesses inherent film-forming ability and biodegradability; however, its limited mechanical and thermal properties constrain its practical applications. In this work, chitosan films were fabricated via compression molding, and their thermo-mechanical performance was systematically evaluated. The incorporation of fillers, such as titanium dioxide and silica, resulted in a 50% enhancement in tensile strength and an 86% improvement in flexibility. Further optimization of dual-filler compositions led to an additional 45% increase in elasticity, demonstrating the potential of synergistic reinforcement. These findings underscore the viability of tailored chitosan composites as high-performance, biodegradable materials for the next generation of sustainable materials. Full article

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15 pages, 5194 KB

Open AccessArticle

Investigations on the Effect of Fluid Jet to Wheel Speed Ratio on Specific Grinding Energy

by Ablie Njie, Tobias Hüsemann and Bernhard Karpuschewski

J. Manuf. Mater. Process. 2026, 10(1), 18; https://doi.org/10.3390/jmmp10010018 - 6 Jan 2026

Viewed by 607

Abstract

The use of metalworking fluid (MWF) in surface grinding is essential, but its supply contributes notably to the process energy demand. This study investigates the effect of the fluid jet to wheel speed ratio q_s on specific grinding energy and associated CO [...] Read more.

The use of metalworking fluid (MWF) in surface grinding is essential, but its supply contributes notably to the process energy demand. This study investigates the effect of the fluid jet to wheel speed ratio q_s on specific grinding energy and associated CO₂ emissions. Experiments with grinding wheels of different grit sizes (F60–F120) were conducted at cutting speeds of 35 and 60 m/s. Critical specific material removal rates Q’_{w, crit} were determined by taper grinding, with the onset of grinding burn identified by Barkhausen noise analysis. Based on these values and the grinding wheel width, specific process energies e_total were derived from grinding, pump, and machine base load. F120 wheels showed no systematic dependence of Q’_{w, crit} on q_s, whereas for coarser F80 and F60 wheels, decreasing q_s from 1.0 to 0.6 increased Q’_{w, crit} by 13–27% at 35 m/s and decreased it by 33–35% at 60 m/s. The most efficient process (F60, 35 m/s, q_s = 0.6) required 152.8 J/mm³, the least efficient (F120, 60 m/s, q_s = 0.8) 333.1 J/mm³. Because CO₂ emissions scale with e_total, the relative differences in energy directly indicate relative differences in CO₂ output. An illustrative case study shows that adjusting q_s alone (F80, 35 m/s) lowers annual emissions from 0.284 t to 0.206 t, a reduction of approximately 27%. These findings highlight the influence of q_s on grinding efficiency and process energy demand. Full article

(This article belongs to the Special Issue Advanced and Sustainable Machining)

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8 pages, 1417 KB

Open AccessCommunication

Integrable Post-Fabrication Annealing Treatment for Polymer-Based Capacitive Micromachined Ultrasonic Transducers: Performance Impacts

by Chenyang Luo, Jonas Welsch, Edmond Cretu, Robert Rohling and Martin Angerer

J. Manuf. Mater. Process. 2026, 10(1), 17; https://doi.org/10.3390/jmmp10010017 - 6 Jan 2026

Viewed by 1309

Abstract

This study investigates the effects of post-fabrication annealing on polymer-based capacitive micromachined ultrasonic transducers (polyCMUTs). These devices comprise microscopic diaphragms produced via photolithographic patterning of polymer layers. Critical point drying, required to release the diaphragms, can cause significant plastic deformation, thereby reducing electromechanical [...] Read more.

This study investigates the effects of post-fabrication annealing on polymer-based capacitive micromachined ultrasonic transducers (polyCMUTs). These devices comprise microscopic diaphragms produced via photolithographic patterning of polymer layers. Critical point drying, required to release the diaphragms, can cause significant plastic deformation, thereby reducing electromechanical coupling. Post-fabrication annealing, carried out in incremental steps up to 190 °C, led to an effective increase in coupling by a factor of 5.4. Atomic Force Microscopy showed that the initial upward deflection of 162.7 nm decreased to 6.2 nm after annealing at 190 °C, while also improving surface uniformity. In parallel, the transducer’s resonance frequency rose from 2.33 MHz (unannealed) to 2.60 MHz, and the input impedance phase angle at resonance increased from −68.1° to −4.3°. Together, these changes indicate a significant improvement in resonator behavior and, consequently, device performance. Thus, post-fabrication annealing is an effective measure to achieve the designed performance while enhancing manufacturing yield, thereby increasing the applicability of polyCMUTs. Full article

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24 pages, 5672 KB

Open AccessArticle

Microstructure Statistical Symmetry, and Quantification of Anisotropic Thermal Conduction in Additive Manufactured Short Carbon Fiber/Polyetherimide Composites

by Tiantian Ke, Harry Hongru Zhou, Soroush Azhdari, Matthias Feuchtgruber and Sergii G. Kravchenko

J. Manuf. Mater. Process. 2026, 10(1), 16; https://doi.org/10.3390/jmmp10010016 - 1 Jan 2026

Viewed by 713

Abstract

This work presents a microstructure-informed pathway for assigning a material symmetry class to distinguish between tensor components and scalar effective thermal conductivity (ETC) values derived from directional measurements. The framework combines directional thermal measurements with three-dimensional statistical quantification of microstructural features (fibers and [...] Read more.

This work presents a microstructure-informed pathway for assigning a material symmetry class to distinguish between tensor components and scalar effective thermal conductivity (ETC) values derived from directional measurements. The framework combines directional thermal measurements with three-dimensional statistical quantification of microstructural features (fibers and voids) to assess whether symmetry assumptions required for tensorial interpretation are justified. Three distinct microstructures of short carbon fiber-reinforced polyetherimide composite were analyzed, with the microstructure statistics altered by the melt extrusion additive manufacturing process parameters. The directional temperature-rise history in the material samples was measured using the Transient Plane Source sensor. The statistics obtained from 3D images of microstructural features were used to assess the material’s anisotropy class to justify the applicability of the transverse isotropic regression method for ETC. One microstructure exhibited characteristics consistent with a statistical transverse isotropy idealization, enabling inference of the ETC tensor; the others did not, and their directional ETC values are treated as test-specific parameters obtained from isotropic model fits. The results also demonstrate that microstructure parameters may strongly influence directional thermal transport. More broadly, this work highlights the need for microstructure-informed justification when interpreting directional measurements as tensor components rather than configuration-dependent scalars, underscoring a critical unresolved gap in the experimental characterization of general anisotropic ETC tensors. Full article

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20 pages, 2969 KB

Open AccessArticle

Influence of Tool Clearance Angle and Cutting Conditions on Tool Life When Turning Ti-6Al-4V—Design of Experiments Approach

by Adam Lukáš, Miroslav Gombár, Jindřich Sýkora, Josef Sklenička, Jaroslava Fulemová and Jan Hnátík

J. Manuf. Mater. Process. 2026, 10(1), 15; https://doi.org/10.3390/jmmp10010015 - 31 Dec 2025

Viewed by 1008

Abstract

The titanium alloy Ti-6Al-4V is widely used in the aerospace, medical, and automotive industries; however, its machining remains challenging due to its low thermal conductivity and high chemical reactivity. This study investigates the influence of the tool clearance angle on tool wear during [...] Read more.

The titanium alloy Ti-6Al-4V is widely used in the aerospace, medical, and automotive industries; however, its machining remains challenging due to its low thermal conductivity and high chemical reactivity. This study investigates the influence of the tool clearance angle on tool wear during the turning of Ti-6Al-4V under wet cutting conditions. A Design of Experiments (DoE) approach was employed, varying the clearance angle, cutting speed, and feed rate to determine their effects on tool wear. Tool wear was analysed using 3D topography measurements. Regression analysis was used to evaluate the experimental data with the main objective of quantifying the impact of the individual factors and their interactions, resulting in the development of a predictive statistical model. The model’s accuracy was assessed using the coefficient of determination (R²) and the adjusted coefficient of determination (R²adj). The results demonstrate that the clearance angle has a significant impact on crater wear formation and overall tool life. An optimised moderate clearance angle reduces tool degradation, enhances tool life, and improves the surface integrity of the machined component. Full article

(This article belongs to the Special Issue Advanced Design, Manufacturing, and Applications of Precision Machine Tools)

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11 pages, 3648 KB

Open AccessArticle

Effect of Casting Speed on Solidification Behavior and Porosity Defects in Low-Oxygen Copper Casting Rods Using SCR Technology

by Qi Yu, Lei Zhang, Tao Wan, Delin Tang, Yong Zhang, Zhiyong Wu, Fangyou Zhong, Shuncong Le, Yang Hu and Hailiang Yu

J. Manuf. Mater. Process. 2026, 10(1), 14; https://doi.org/10.3390/jmmp10010014 - 31 Dec 2025

Viewed by 1047

Abstract

The Southwire Continuous Rod (SCR) process is widely used for producing low-oxygen copper rods, yet pore defects remain a significant challenge, affecting the performance and drawability of copper wire. In this study, the influence of casting speed on solidification behavior and porosity formation [...] Read more.

The Southwire Continuous Rod (SCR) process is widely used for producing low-oxygen copper rods, yet pore defects remain a significant challenge, affecting the performance and drawability of copper wire. In this study, the influence of casting speed on solidification behavior and porosity formation in low-oxygen copper casting rods was investigated by combining numerical simulation and plant trials. The simulation results indicate that increasing the casting speed elevates the flow velocity and impact depth of molten copper in the casting wheel. Simultaneously, higher casting speeds could raise the temperature of the casting rod and extend the liquid phase region, which suppresses the precipitation of dissolved gases from the melt. However, when the casting speed exceeds 26 t/h, the center temperature of the casting rod at the outlet remains close to the melting point of copper, retaining 10–20% liquid fraction. This predisposes the rod to remelting and the formation of remelt holes, and thus it fails to meet the design requirement for complete solidification of the SCR technology. Further industrial trials confirm that a casting speed of 23 t/h is optimal under current process conditions, yielding the lowest size and number of porosity defects in the casting rod. Full article

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18 pages, 4914 KB

Open AccessArticle

Study on the Performance of Aerospace High-Strength Titanium Alloy TC4 Countersunk Head Bolts for Special Connections in Multi-Working Conditions

by Lang Wei, Guang Yu, Weishao Feng, Jie Wang and Lai Hu

J. Manuf. Mater. Process. 2026, 10(1), 13; https://doi.org/10.3390/jmmp10010013 - 30 Dec 2025

Viewed by 765

Abstract

Titanium alloy TC4 countersunk head bolts (CHB) are widely used in spacecraft structures, but the research on CHB does not receive enough attention at present. There are still some more opportunities worthy of in-depth research, such as insufficient research on CHB of high-strength [...] Read more.

Titanium alloy TC4 countersunk head bolts (CHB) are widely used in spacecraft structures, but the research on CHB does not receive enough attention at present. There are still some more opportunities worthy of in-depth research, such as insufficient research on CHB of high-strength fasteners for aerospace applications, an insufficient combination of CHB simulation tests with real working conditions, and inspection and testing methods. In this study, through the combination of finite element simulation and experiments, the working conditions of the CHB connection structure bearing tensile load and CHB screwing were analyzed, and the requirements of the CHB connection structure and installation of CHB were optimized. Based on the single-bolt tensile simulation, the working conditions of multi-bolt connection structures under eccentric load and single-bolt composite laminate connection structures under tensile load were analyzed. Meanwhile, the structure of CHB was further optimized, and the simulation analysis model of the CHB tightening process was established. The research shows that the larger fixing bolt countersunk angle θ₁ and the smaller countersunk fillet radius r, the better the ultimate bearing capacity of the connection structure will be. When the countersunk bevel angle of pressure plate θ₂ was greater than or less than 100°, the clamping force–angle slope will decrease, while when θ₂ was smaller, it will have a greater influence on the slope. The coaxiality Φ had little influence on the slope around the allowable tolerance range (0.3 mm), but the influence on the slope becomes greater when it exceeds the tolerance range. The research results provide a reference and basis for the layout of CHB and the use of composite materials in aerospace connection structures. Full article

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J. Manuf. Mater. Process., Volume 10, Issue 1 (January 2026) – 42 articles

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