Journal of Manufacturing and Materials Processing

29 pages, 5930 KB

Open AccessArticle

Simulation-Based Prediction of Milling-Induced Shape Errors on Compliant, Additively Manufactured Components

by Berend Denkena, Klaas Maximilian Heide, Roland Lachmayer, Jens Niedermeyer and Fabian Schlenker

J. Manuf. Mater. Process. 2026, 10(8), 310; https://doi.org/10.3390/jmmp10080310 - 21 Aug 2026

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Additively manufactured components require machining of functional surfaces to meet geometric requirements. Due to low stiffness and non-nominal as-built geometry, they are susceptible to milling-induced shape deviations. This paper presents a geometric–numerical milling process simulation for predicting shape errors in compliant metallic laser [...] Read more.

Additively manufactured components require machining of functional surfaces to meet geometric requirements. Due to low stiffness and non-nominal as-built geometry, they are susceptible to milling-induced shape deviations. This paper presents a geometric–numerical milling process simulation for predicting shape errors in compliant metallic laser powder bed fusion components. The method combines real-geometry-based technological numerical control simulation, quasi-static force prediction, finite element-based structural response simulation, and surface reconstruction between roughing and finishing to enable multistage operation. The approach is validated for linear and non-linear toolpaths with varying immersion angles and compliance conditions. The results show reproduced force profiles, while magnitude deviations highlight the relevance of deformation-dependent engagement feedback in high-compliance regions. An analytical back-calculation based on the effective engagement cross-section reveals that accounting for deflection-induced engagement reduction reduces force deviations. During roughing, maximum shape errors for linear and non-linear toolpaths are overestimated by 4–5%, and critical high-error regions are identified. The reconstructed intermediate geometry after roughing is essential for finishing, since neglecting geometry feedback underestimates finishing forces. With geometry feedback, the maximum finishing shape error is predicted as 0.090 mm, while the measured value is 0.086 mm. The simulation captures dominant quasi-static shape-error regimes and supports process-chain-oriented prediction in additive–subtractive manufacturing. Full article

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21 pages, 22912 KB

Open AccessArticle

Filament Heating Voltage Effects on Cathode Operation and Weld Formation in Thin-Sheet Ti-6Al-4V Electron-Beam Welding

by Xinmin Shi, Junbiao Zhao, Zhiqiang Cao, Xueying Zhang, Ruonan Wang and Defeng Mo

J. Manuf. Mater. Process. 2026, 10(8), 309; https://doi.org/10.3390/jmmp10080309 - 21 Aug 2026

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Abstract

Filament heating voltage governs thermionic electron emission in electron-beam guns, but its influence on weld formation under fixed electron-beam welding settings has received limited quantitative investigation. In this study, Ti-6Al-4V thin sheets were welded at filament heating voltages of 2.8–3.4 V, while the [...] Read more.

Filament heating voltage governs thermionic electron emission in electron-beam guns, but its influence on weld formation under fixed electron-beam welding settings has received limited quantitative investigation. In this study, Ti-6Al-4V thin sheets were welded at filament heating voltages of 2.8–3.4 V, while the accelerating voltage, beam current, focusing current, and welding speed were kept constant. Weld cross-sections were characterized experimentally, and the resulting thermal process was analyzed using a simplified cathode-emission calculation and finite element thermal analysis. A clear change in weld penetration behavior was observed within approximately 3.2–3.3 V. The weld aspect ratio increased from approximately 0.4 below this region to approximately 0.6 at 3.3 V and further to approximately 0.63 at 3.4 V. Concurrent changes in the required bias voltage, calculated equivalent cathode area, and weld geometry were consistent with a change toward a more stable cathode operating condition. The weld-geometry changes were also consistent with a change in the effective beam-energy distribution, although the beam profile was not measured directly. These results show that filament heating voltage should be treated as an independent equipment-side control variable even when the main electron-beam welding settings remain unchanged. Although the specific transition range depends on the electron gun, beam-current setting, and cathode condition, the electrical-response-based identification approach may provide a practical method for identifying the filament operating range when direct beam diagnostics are unavailable. Full article

(This article belongs to the Special Issue Advances in Welding Technology: 2nd Edition)

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28 pages, 633 KB

Open AccessReview

Smart Factories, Smarter Research: A Critical Review of Manufacturing 4.0 Technologies, Sustainability, and the Road to Industry 5.0

by Ahmed S. Alghamdi

J. Manuf. Mater. Process. 2026, 10(8), 308; https://doi.org/10.3390/jmmp10080308 - 20 Aug 2026

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Abstract

Industry 4.0 has produced one of the fastest-growing bodies of engineering and management research; much of this output remains siloed by technology domain. This study addresses that fragmentation through a structured critical review (a review-of-reviews), synthesising 70 peer-reviewed review articles and foundational sources [...] Read more.

Industry 4.0 has produced one of the fastest-growing bodies of engineering and management research; much of this output remains siloed by technology domain. This study addresses that fragmentation through a structured critical review (a review-of-reviews), synthesising 70 peer-reviewed review articles and foundational sources (2003–2026) spanning 14 technology domains. The review introduces the I4.0-STS framework, an original four-layer structure organising evidence across physical, cyber, cognitive, and socio-organisational dimensions. Five principal findings emerge. The physical and cyber layers show consistent evidence of maturity. Industry-reported lighthouse IIoT deployments show 20–30% energy and up to 39% lead-time reductions. AI-driven predictive maintenance shows 30–50% unplanned-downtime reductions. The cognitive layer (LLM-augmented digital twins and generative AI interfaces) is technically feasible but outpaces its governance frameworks. Cybersecurity remains insufficiently governed, with documented ransomware incidents in manufacturing OT environments underscoring the risks of OT–IT convergence. SME adoption and developing-economy manufacturing transformation remain comparatively under-addressed. Finally, 12 research gaps are assessed as of June 2026, five rated Open, with future research directions proposed for each, framed against the emerging Industry 5.0 agenda. All findings are second-order interpretations from the source reviews, and their limitations are stated explicitly. Full article

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18 pages, 4282 KB

Open AccessArticle

Experimental Investigation and Artificial Neural Network-Based Prediction of Tensile Strength in Fused Filament-Fabricated Carbon Fiber-Reinforced PETG

by Ahmed Hadi, Abdulkader Kadauw, Mohanned M. H. AL-Khafaji and Henning Zeidler

J. Manuf. Mater. Process. 2026, 10(8), 307; https://doi.org/10.3390/jmmp10080307 - 20 Aug 2026

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Abstract

Fused filament fabrication (FFF) has become an important additive manufacturing technique for producing functional polymer-composite components. The tensile performance of carbon fiber-reinforced polyethylene terephthalate glycol (PETG/CF) fabricated by FFF depends on multiple printing parameters. This study presents an integrated experimental and predictive framework [...] Read more.

Fused filament fabrication (FFF) has become an important additive manufacturing technique for producing functional polymer-composite components. The tensile performance of carbon fiber-reinforced polyethylene terephthalate glycol (PETG/CF) fabricated by FFF depends on multiple printing parameters. This study presents an integrated experimental and predictive framework for investigating the effects of extrusion temperature, printing speed, layer height, infill pattern, and infill density on the tensile strength of PETG/CF containing 15 wt.% carbon fiber. A mixed-level Taguchi L36 orthogonal array was employed, comprising 36 experimental runs with three independently printed specimens per run, resulting in 108 ASTM D638 Type V specimens. Analysis of variance showed that the printing speed had the largest contribution to tensile strength (20.51%), followed by layer height (18.29%). The highest tensile strength of 33.225 MPa was obtained using grid infill, 60% infill density, 270 °C extrusion temperature with 40 mm/s printing speed, and 0.3 mm layer height. An artificial neural network (ANN) was developed for the tensile-strength prediction, achieving R = 0.9801, R² = 0.9569, and MAPE = 1.52% for the overall dataset. Scanning electron microscopy qualitatively revealed bead-interface defects, fiber pullout, and localized void-like features. The proposed framework provides a systematic approach for evaluating process-parameter effects and predicting tensile strength within the investigated PETG/CF parameter domain. Full article

(This article belongs to the Special Issue Recent Advances in Optimization of Additive Manufacturing Processes)

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26 pages, 10274 KB

Open AccessArticle

Crystal Plasticity Assessment of Texture Discretization and Lamellar Grain Morphology for Predicting the Anisotropic Behavior of LPBF IN718

by José David Pérez-Ruiz, Jorge Pinzón, Andres Gonzalez, Luis Norberto Lopez de LaCalle and Jorge Bris

J. Manuf. Mater. Process. 2026, 10(8), 306; https://doi.org/10.3390/jmmp10080306 - 20 Aug 2026

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Abstract

The anisotropic mechanical behavior of laser powder bed fused (LPBF) IN718 results from the combined effects of crystallographic texture and grain morphology, although their individual contributions remain difficult to quantify. In this work, six representative volume elements (RVEs) are systematically compared using a [...] Read more.

The anisotropic mechanical behavior of laser powder bed fused (LPBF) IN718 results from the combined effects of crystallographic texture and grain morphology, although their individual contributions remain difficult to quantify. In this work, six representative volume elements (RVEs) are systematically compared using a unified EBSD–Dream3D–DAMASK crystal plasticity framework to separate the effects of texture and morphology. The microstructures include two EBSD-derived RVEs, two discretized columnar RVEs, and two discretized lamellar RVEs generated from identical orientation distributions. Predicted elastic moduli and yield strengths are validated against experiment, while Taylor factor analysis, directional effective grain size, slip compatibility, KAM, and local crystal plasticity fields are used to identify the governing deformation mechanisms. The results show that crystallographic texture predominantly controls the elastic response, whereas grain morphology governs the onset of plastic deformation. Lamellar RVEs provide the closest agreement with the experimental yield-strength anisotropy by reproducing the directional effective grain size, the connectivity of mechanically hard domains, and the resulting redistribution of stress and plastic strain. Furthermore, texture discretization preserves the dominant anisotropic trends while substantially reducing the computational cost of full EBSD reconstructions, establishing an efficient and physically meaningful framework for crystal plasticity simulations of LPBF materials. Full article

(This article belongs to the Special Issue Next-Generation Machine Tools and Machining Technology)

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18 pages, 13132 KB

Open AccessArticle

PCD Tool Wear Mechanism and Prediction in Laser–Ultrasonic Synergistic Milling of High-Volume-Fraction SiC_p/Al Composites

by Liquan Yang, Kun Zhao, Jianhao Qi, Erbo Liu, Sen Yuan, Qingqing Lü and Guangxi Li

J. Manuf. Mater. Process. 2026, 10(8), 305; https://doi.org/10.3390/jmmp10080305 - 19 Aug 2026

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Abstract

To address severe PCD tool wear during the milling of high-volume-fraction SiC_p/Al composites, a synergistic milling process coupling pulsed laser pretreatment with ultrasonic vibration was proposed. Five-factor, four-level orthogonal experiments were conducted on 70 vol.% SiC_p/Al composites to investigate [...] Read more.

To address severe PCD tool wear during the milling of high-volume-fraction SiC_p/Al composites, a synergistic milling process coupling pulsed laser pretreatment with ultrasonic vibration was proposed. Five-factor, four-level orthogonal experiments were conducted on 70 vol.% SiC_p/Al composites to investigate the effects of milling speed, feed per tooth, cutting depth, laser power, and ultrasonic amplitude on milling forces and tool wear, and a tool wear prediction model was established. The results showed that the factors influencing tool wear, in descending order, were feed per tooth, cutting depth, milling speed, laser power, and ultrasonic amplitude. Appropriate laser power and ultrasonic amplitude reduced cutting loads and suppressed tool wear. The model achieved a coefficient of determination of 0.7887 and was statistically significant overall. The optimal parameter combination was 50 m/min, 0.02 mm/z, 0.1 mm, 60 W, and 3.5 μm, under which the tool wear loss was 1.0 mg, representing a reduction of 61.54% compared with the maximum-wear condition. The main wear modes of the PCD tool included rake-face grooving and fatigue spalling, flank-face abrasive wear, and cutting-edge micro-chipping. These findings provide a useful reference for the precision milling of SiC_p/Al composites. Full article

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26 pages, 67124 KB

Open AccessArticle

Drilling Performance Evaluation and Mechanism Analysis of Diamond-Coated Drills in Ice-Supported CFRP Machining

by Bohan Yuan, Yixin Jin, Ming Jin, Wenjie Zhang, Bin Wan, Huaxing Yang and Zhao Zhang

J. Manuf. Mater. Process. 2026, 10(8), 304; https://doi.org/10.3390/jmmp10080304 - 18 Aug 2026

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Abstract

Diamond-coated tools are suitable for CFRP machining because of their high hardness, sharp cutting edge, and good wear resistance. However, the anisotropic and heterogeneous nature of CFRP makes drilling-induced defects, such as burrs, tearing, fiber pull-out, and delamination, difficult to avoid, especially at [...] Read more.

Diamond-coated tools are suitable for CFRP machining because of their high hardness, sharp cutting edge, and good wear resistance. However, the anisotropic and heterogeneous nature of CFRP makes drilling-induced defects, such as burrs, tearing, fiber pull-out, and delamination, difficult to avoid, especially at the hole exit. In this study, an ice-supported drilling method was proposed for CFRP hole machining using diamond-coated drills. An ice layer was formed beneath the CFRP laminate to provide simultaneous low-temperature cooling and mechanical support during drilling. Comparative drilling experiments were conducted at spindle speeds of 400, 1200, and 2000 r/min. The results showed that the ice-supported drilling method markedly improved the hole surface quality and inner-wall integrity of CFRP laminates. Compared with conventional dry drilling, the drilling temperature was reduced by 22.03%, 10.70%, and 11.45% at 400, 1200, and 2000 r/min, respectively, while the hole-exit delamination factor decreased by 41.68%, 27.45%, and 57.04%, respectively. Moreover, after the same number of drilled holes, the diamond-coated drill used under ice-supported conditions exhibited less severe surface wear and cutting-edge blunting than that used under conventional dry conditions. The observed improvements were interpreted as being associated with the combined thermal-regulation and temporary mechanical-backing effects of the ice-supported condition. Full article

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24 pages, 8073 KB

Open AccessArticle

Repair of a Complex Ti-6Al-4V Groove by Coaxial Wire Laser Metal Deposition: Process Window, Tensile, and Very-High-Cycle Fatigue Evaluation

by Owen Sutherland, Ryan Devine and Yevgen Gorash

J. Manuf. Mater. Process. 2026, 10(8), 303; https://doi.org/10.3390/jmmp10080303 - 18 Aug 2026

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Abstract

Ti-6Al-4V has seen widespread adoption in the aerospace industry due to its advantageous material properties, but the alloy is costly to produce with vulnerable supply chains. Repair and remanufacture offer economic and environmental benefits over scrapping components. Powder-based additive-manufacturing processes have been investigated; [...] Read more.

Ti-6Al-4V has seen widespread adoption in the aerospace industry due to its advantageous material properties, but the alloy is costly to produce with vulnerable supply chains. Repair and remanufacture offer economic and environmental benefits over scrapping components. Powder-based additive-manufacturing processes have been investigated; however, coaxial wire laser metal deposition (LMD) remains understudied in repair scenarios, and the transfer of planar process parameters to inclined geometries for complex repairs has not been established. This paper identifies a process window for 1.2 mm Ti-6Al-4V wire and applies the parameters to repair a trapezoidal groove. Tensile and fatigue properties are evaluated, and fractography is conducted using optical and scanning electron microscopy. Findings show the transfer from planar to inclined geometry induces evolving geometric and thermal boundary conditions, including underbuilding and thermal accumulation. Nonetheless, the repair exhibited a yield strength of 868.2 MPa, an ultimate tensile strength of 920.5 MPa, and an elongation of 8.9%. Moreover, UFT revealed a fatigue performance of the repairs that was consistent with heat-treated SLM materials. Fractographic analysis revealed triangular defects and feedstock contamination that contribute to reduced repair properties. As such, this paper demonstrated that coaxial wire-LMD can be used to deposit material into complex geometries, but a complete, defect free repair was not achieved. Full article

(This article belongs to the Special Issue Advancements in Metal Additive Manufacturing: Technologies and Applications)

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16 pages, 4197 KB

Open AccessArticle

Influence of CNT Reinforcement and Fiber Orientation on the Mechanical Performance of Woven Kevlar/Epoxy Composites

by Muhammad Umair Najeem, Zarak Khan, Muhammad Younas and Taimoor Asim

J. Manuf. Mater. Process. 2026, 10(8), 302; https://doi.org/10.3390/jmmp10080302 - 18 Aug 2026

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Abstract

Carbon nanotubes (CNTs) are widely used as nanoscale reinforcements in polymer composites because of their high stiffness, high aspect ratio, and ability to enhance interfacial stress transfer. In woven Kevlar/epoxy composites, however, the mechanical benefit of CNT addition depends not only on nanotube [...] Read more.

Carbon nanotubes (CNTs) are widely used as nanoscale reinforcements in polymer composites because of their high stiffness, high aspect ratio, and ability to enhance interfacial stress transfer. In woven Kevlar/epoxy composites, however, the mechanical benefit of CNT addition depends not only on nanotube presence, but also on whether the fabric Fiber orientation enables the CNT-modified interface to participate effectively in the dominant load path. In this study, woven Kevlar/epoxy composites with and without 4 wt.% multi-walled carbon nanotube (MWCNT) treatment were investigated under three displacement rates, namely 1, 10, and 100 mm/s, for two specimen orientations relative to the woven yarn directions: 0°/90° and ±45°. The 0°/90° Fiber orientation represents a tension-dominant load path, whereas the ±45° Fiber orientation promotes yarn rotation and matrix-shear-dominant deformation. The experimental results show that CNT treatment produces a clear increase in elastic modulus in the 0°/90° composites, with an improvement of approximately 40–50% at the lowest loading rate and continued enhancement at higher rates. In contrast, only limited gains are observed in the ±45° composites. The calculated CNT engagement index reached 0.8667 in the 0°/90° Fiber orientation but remained low or negative in some ±45° loading conditions, indicating that the effectiveness of CNT reinforcement depends strongly on Fiber orientation relative to the woven yarn directions. To interpret this behavior in a design-oriented manner, three Fiber orientation-sensitive comparison parameters are introduced: the CNT engagement index, the Fiber orientation sensitivity factor, and the rate amplification factor. These descriptors distinguish absolute stiffness from actual reinforcement utilization and indicate that modulus improvements depend on specimen orientation relative to the woven yarn directions. This study indicates that fabric Fiber orientation governs whether the CNT-modified interface is effectively mobilized or largely bypassed. This provides a useful framework for selectively deploying CNT reinforcement in woven protective composite systems and for rethinking nanotube reinforcement as a load-path-dependent design feature rather than a universally effective additive. Full article

(This article belongs to the Special Issue Processing, Mechanical Properties, and Manufacturing Techniques of Advanced Composite Materials)

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20 pages, 7895 KB

Open AccessArticle

A Rapid Separation Method of Spindle Radial Error Motion Under Cutting Conditions

by Xinping Xu, Yue Tao, Tao Geng and Tao Tao

J. Manuf. Mater. Process. 2026, 10(8), 301; https://doi.org/10.3390/jmmp10080301 - 18 Aug 2026

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Abstract

Measuring the radial error motion of a spindle during the cutting process is important for monitoring the machining quality of the workpiece and spindle running condition. The problem of long separation time encountered in the application of traditional methods is analyzed under cutting [...] Read more.

Measuring the radial error motion of a spindle during the cutting process is important for monitoring the machining quality of the workpiece and spindle running condition. The problem of long separation time encountered in the application of traditional methods is analyzed under cutting conditions. A rapid separation strategy based on step separation is studied. Combining the advantages of the bidirectional measurement and multi-probe methods, a rapid separation method for spindle radial error motion is proposed. Based on the characteristics of the first harmonic components at high and low spindle speeds, an extraction method for the installation eccentricity is developed. The spindle built-in encoder acquisition technology and angle position resampling method are used to reduce the influence of cutting conditions on error separation. Finally, an actual cutting experiment is conducted to verify the effectiveness of the proposed method, and it is shown that the proposed method cannot only achieve rapid separation but also obtain better separation accuracy under cutting conditions. Full article

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26 pages, 6267 KB

Open AccessArticle

Modeling and Prediction of the Forming Limits of AA5052 Sheets Under Cryogenic Conditions Using a Modified M-K Model

by Haolei Zhang, Zeng Tan, Zhide Li, Denis Pustovoytov, Alexander Pesin and Hailiang Yu

J. Manuf. Mater. Process. 2026, 10(8), 300; https://doi.org/10.3390/jmmp10080300 - 17 Aug 2026

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Abstract

Cryogenic forming overcomes room-temperature limitations by leveraging the enhanced strength–ductility synergy in Al alloys. To explore the forming limits of AA5052 sheet under cryogenic forming conditions, quasi-in situ tensile tests were conducted and digital image correlation techniques were employed to examine strain distribution, [...] Read more.

Cryogenic forming overcomes room-temperature limitations by leveraging the enhanced strength–ductility synergy in Al alloys. To explore the forming limits of AA5052 sheet under cryogenic forming conditions, quasi-in situ tensile tests were conducted and digital image correlation techniques were employed to examine strain distribution, surface roughness evolution, and forming limit curves of the AA5052 sheet in the tensile deformation process. Experimental results show that the maximum equivalent forming limit at −196 °C increases to 50.7% from 19.9% at room temperature, representing a 250% increase. At the same time, the surface roughness evolution rate increases by 60% from 2713 nm at room temperature to 4414 nm at −196 °C. Cryogenic conditions suppress dislocation annihilation and dynamic recovery, enhancing strain hardening, resulting in higher forming limits. Additionally, intensified grain rotation and more dislocation slip accelerate surface roughening, which influences the development of the geometric heterogeneity coefficient. By introducing a strain-dependent surface roughening coefficient, the Marciniak–Kuczyński (M-K) model was modified and was used to quantitatively characterize the heterogeneity during deformation, and subsequently analyzes its impact on the prediction of forming limits for AA5052 from room temperature (25 °C) to cryogenic temperature (−196 °C). The modified model reduces the prediction standard deviation by more than 70% and the identified mechanisms offer theoretical guidance for optimizing cryogenic forming process parameters for Al alloy components with complex geometries. Full article

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14 pages, 2831 KB

Open AccessArticle

Microstructural Features and Defect Formation in Plasma-Sprayed Al₂O₃ Coatings Deposited by a Water-Stabilized Plasma Torch

by Jozef Výboch, Samuel Mikita and Ján Viňáš

J. Manuf. Mater. Process. 2026, 10(8), 299; https://doi.org/10.3390/jmmp10080299 - 15 Aug 2026

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Abstract

Al₂O₃ coatings were deposited on S235J2 steel substrates using a water-stabilized plasma (WSP) spraying system equipped with a WSP PAL-160 plasma torch. The microstructure, phase composition and adhesion behaviour of the deposited coatings were investigated. Cross-sectional and surface observations were [...] Read more.

Al₂O₃ coatings were deposited on S235J2 steel substrates using a water-stabilized plasma (WSP) spraying system equipped with a WSP PAL-160 plasma torch. The microstructure, phase composition and adhesion behaviour of the deposited coatings were investigated. Cross-sectional and surface observations were performed using scanning electron microscopy (SEM), while phase composition was evaluated by X-ray diffraction analysis. The coatings exhibited a characteristic lamellar architecture formed by successive deposition and rapid solidification of molten particles. The most frequently observed defects were interlamellar pores, isolated rounded pores and fine microcracks located within individual lamellae. Despite the presence of these discontinuities, the coating formed a continuous layer without extensive delamination. X-ray diffraction analysis revealed that the deposited coating consisted predominantly of γ-Al₂O₃, whereas only a minor fraction of α-Al₂O₃ was detected. The predominance of γ-Al₂O₃ was attributed to rapid cooling of molten particles after impact on the substrate surface. Adhesion testing performed according to ASTM C633 yielded an average adhesion strength of approximately 10.58 ± 0.36 MPa and revealed a mixed adhesive–cohesive failure mode. The obtained results confirm that water-stabilized plasma spraying is capable of producing Al₂O₃ coatings with a typical lamellar microstructure, adequate adhesion and phase composition characteristic of rapidly solidified alumina deposits. Full article

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20 pages, 3195 KB

Open AccessArticle

Importance of Characterizing Heat Transfer in Both the Tool and Workpiece for Friction Stir Welding Thermal Model Validation

by Muhammad Taha, Matthew Goodson, Ryan Melander, Troy Munro and Michael P. Miles

J. Manuf. Mater. Process. 2026, 10(8), 298; https://doi.org/10.3390/jmmp10080298 - 15 Aug 2026

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Abstract

Accurate thermal modeling of friction stir welding (FSW) requires correct representation of heat generation and heat partitioning at the workpiece/tool interface. However, most published models are validated against temperature measurements from only one side of this interface, so agreement with experiment does not [...] Read more.

Accurate thermal modeling of friction stir welding (FSW) requires correct representation of heat generation and heat partitioning at the workpiece/tool interface. However, most published models are validated against temperature measurements from only one side of this interface, so agreement with experiment does not guarantee that interfacial heat transfer is correctly represented. This study evaluates whether one-sided temperature validation is sufficient, using steady-state FSW of AA 6061-T6 aluminum with an H13 steel tool. Temperatures were measured with thermocouples embedded in both the workpiece and the tool, and a Eulerian thermomechanical model was developed in ForgeNxt. The viscoplastic friction coefficient and the workpiece/tool heat transfer coefficient were calibrated against tool temperatures only, workpiece temperatures only, and both simultaneously. Tool-only calibration reproduced tool temperatures within 2.5% but overpredicted workpiece temperatures by 18% on average; workpiece-only calibration achieved 5% average workpiece error but underpredicted tool temperatures by 26%. Sensitivity analysis showed that workpiece temperatures were governed primarily by the friction coefficient, while tool temperatures were sensitive to both friction coefficient and heat transfer coefficient. No single parameter pair reproduced both temperature sets, indicating that one-sided validation can produce misleading agreement and that two-sided validation is necessary to achieve accurate interfacial heat partitioning. Full article

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15 pages, 7194 KB

Open AccessArticle

Thermal Aging and Geometry-Driven Changes in Strength of 3D-Printed Polymers

by Mohammad Reza Khosravani, Payam Soltani, Morteza Mohammadzaheri and Majid R. Ayatollahi

J. Manuf. Mater. Process. 2026, 10(8), 297; https://doi.org/10.3390/jmmp10080297 - 14 Aug 2026

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Abstract

The benefits of additive manufacturing (AM, i.e., 3D printing) have made it one of the most widely used and favored production techniques across a variety of industries. In the current study, the influence of geometry and thermal aging on the mechanical strength of [...] Read more.

The benefits of additive manufacturing (AM, i.e., 3D printing) have made it one of the most widely used and favored production techniques across a variety of industries. In the current study, the influence of geometry and thermal aging on the mechanical strength of AMed parts has been investigated. In this context, specimens based on fused deposition modeling were printed using polylactic acid material. The specimens with three distinct geometries were created and analyzed since the geometry of AMed parts affects their mechanical performance. In this study, tensile tests were conducted under static loading circumstances, specifically on dumbbell-shaped, smooth, and V-notched test coupons. Furthermore, we conducted accelerated thermal aging between

- 5 °

C and 35 °C, which is below the glass temperature of the material under investigation, to assess the impact of the thermal environment. In addition, a series of finite element models were developed to study the stress distribution and deformation in the examined components. According to the results, for unaged specimens, smooth samples demonstrated the highest fracture load at 1980.5 N, while dumbbell-shaped samples recorded the lowest at 1173.9 N. Moreover, the V-notched specimens sustained higher fracture loads compared to dumbbell-shaped samples across both aged and unaged conditions. This study’s findings demonstrate that in designing 3D-printed parts, consideration must be given to their geometric appearance and environmental operating circumstances. Full article

(This article belongs to the Special Issue Next-Generation Material Designs and Processes for Additive Manufacturing)

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16 pages, 26836 KB

Open AccessArticle

Effect of Normal Load on Wear Behavior of Low-Temperature Plasma-Nitrided TC4 Titanium Alloy

by Zhiming Xiong, Zhitao Cao, Jianyi Zhang, Fengling Wu, Guoqiang Duan, Leqing Zhao, Peibo Li, Wenjiang Jin, Changzhou Cui and Hui Li

J. Manuf. Mater. Process. 2026, 10(8), 296; https://doi.org/10.3390/jmmp10080296 - 14 Aug 2026

Viewed by 342

Abstract

TC4 titanium alloy suffers from inferior wear resistance, which severely restricts its service in tribological key components, including aero-engine compressor blades and aircraft landing gear. Although plasma nitriding can strengthen alloy surfaces, conventional high-temperature nitriding frequently induces matrix grain coarsening, deteriorated mechanical properties, [...] Read more.

TC4 titanium alloy suffers from inferior wear resistance, which severely restricts its service in tribological key components, including aero-engine compressor blades and aircraft landing gear. Although plasma nitriding can strengthen alloy surfaces, conventional high-temperature nitriding frequently induces matrix grain coarsening, deteriorated mechanical properties, and workpiece dimensional distortion. In this study, low-temperature plasma nitriding was performed on TC4 alloys at 700 °C and 750 °C, and reciprocating wear behaviors under 5 N, 10 N, and 15 N normal loads were systematically investigated. A TiN/Ti₂N compound layer was fabricated on the alloy surface after nitriding. When the nitriding temperature rose from 700 °C to 750 °C, the nitride layer thickness increased from 2.07 µm to 2.75 µm, and surface hardness increased from 507.67 HV to 592.37 HV, far exceeding the 309.70 HV of the original substrate. All nitrided specimens exhibited significantly lower wear depths and specific wear rates than the untreated TC4 alloy, which was associated with the increased surface hardness and the formation of the nitrided layer. The specimen nitrided at 750 °C exhibited shallower wear scars and lower specific wear rates under all investigated loads, demonstrating better load adaptability and wear resistance. Plasma nitriding fundamentally switches the primary wear mechanism of TC4 alloy from severe adhesive-abrasive wear to mild abrasive wear with minor oxidation and micro-spallation. Full article

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18 pages, 13115 KB

Open AccessArticle

Parametric Optimization of the Geometric Parameters of a Combined Friction Face Milling Cutter

by Gulnur Abdugaliyeva, Karibek Sherov, Medgat Mussayev, Zhanibek Tolganay, Javohir Toshov, Bakytzhan Donenbayev, Sabit Magavin and Abay Bobeyev

J. Manuf. Mater. Process. 2026, 10(8), 295; https://doi.org/10.3390/jmmp10080295 - 13 Aug 2026

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Abstract

This study presents a parametric optimization model for the friction disc of a combined friction face milling cutter operating under intensive contact friction, high clamping forces, and cyclic thermomechanical loading. The computational framework integrates ANSYS Workbench, the Static Structural module, Design of Experiments [...] Read more.

This study presents a parametric optimization model for the friction disc of a combined friction face milling cutter operating under intensive contact friction, high clamping forces, and cyclic thermomechanical loading. The computational framework integrates ANSYS Workbench, the Static Structural module, Design of Experiments (DOE), Kriging surrogate modeling, and Multi-Objective Genetic Algorithm (MOGA) optimization. The friction disc geometry is defined by two design variables: the radial depth of the relief groove, a (3–6 mm), and its axial width, b (3–8 mm). Structural performance is evaluated using the von Mises equivalent stress and axial displacement of the cutting zone. Heat-treated 65G spring steel, with a yield strength of 640 MPa, is selected as the material. Using a safety factor of four, the allowable stress is limited to 160 MPa, while the permissible axial displacement is 0.05 mm to satisfy axial runout requirements for face milling cutters. Finite element analysis and response surface modeling show that parameter a predominantly affects axial deformation, whereas the combined influence of a and b governs the acceptable stress region. Multi-Objective Genetic Algorithm (MOGA) optimization identifies design solutions satisfying both strength and stiffness constraints. The proposed approach enables the determination of the minimum admissible values of the geometric parameters a and b while satisfying the prescribed strength, stiffness, and axial displacement constraints. Full article

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19 pages, 3280 KB

Open AccessArticle

Dependence of Discharge Energy and Material Removal Dynamics on Tool Electrode–Workpiece Material Combinations in Electrical Discharge Machining

by Chen Liu, Xiaodong Yang, Qi Li and Xiaoming Duan

J. Manuf. Mater. Process. 2026, 10(8), 294; https://doi.org/10.3390/jmmp10080294 - 13 Aug 2026

Viewed by 364

Abstract

Electrical discharge machining (EDM) demonstrates significant advantages in machining difficult-to-cut materials, particularly those with high hardness and brittleness, owing to its thermally driven material removal mechanism in which the arc plasma serves as the heat source. However, machining performance varies markedly across different [...] Read more.

Electrical discharge machining (EDM) demonstrates significant advantages in machining difficult-to-cut materials, particularly those with high hardness and brittleness, owing to its thermally driven material removal mechanism in which the arc plasma serves as the heat source. However, machining performance varies markedly across different workpiece materials. Such differences are likely attributable to the coupled effects of arc plasma characteristics, which may vary with tool–workpiece material combinations, and the thermophysical properties of the workpiece. Nevertheless, the mechanisms underlying this coupling remain poorly understood. In this study, arc plasma characteristics and material removal behavior under different material combinations were investigated using arc plasma and thermo-hydrodynamic simulation models. Under positive polarity, a copper tool electrode was paired with 304 stainless steel, Ti-6Al-4V, and Inconel 718 workpieces, while copper and tungsten electrodes were compared using a 304 stainless steel workpiece. Simulation results show that material combinations significantly affect anode heat flux and energy distribution, with 304 stainless steel exhibiting the highest heat flux and Inconel 718 receiving the largest energy distribution ratio. Crater depth correlates strongly with heat flux magnitude, while crater diameter is jointly determined by heat flux radius and melt flow dynamics, with the selected cathode material exerting only minor influence. High-speed imaging and crater morphology measurements validate the simulation results, confirming model reliability. These findings provide theoretical guidance for process optimization in EDM. Full article

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33 pages, 780 KB

Open AccessReview

Learning from Demonstration for Robotic Deburring and Polishing: A Systematic Mapping Study

by Ercan Düzgün

J. Manuf. Mater. Process. 2026, 10(8), 293; https://doi.org/10.3390/jmmp10080293 - 12 Aug 2026

Viewed by 395

Abstract

Contact-rich manufacturing processes, such as surface cleaning, deburring, and polishing, require precise force regulation and complex trajectory tracking that are challenging to automate using conventional robot programming methods. Learning from Demonstration (LfD) offers a powerful alternative to transfer these expert skills from human [...] Read more.

Contact-rich manufacturing processes, such as surface cleaning, deburring, and polishing, require precise force regulation and complex trajectory tracking that are challenging to automate using conventional robot programming methods. Learning from Demonstration (LfD) offers a powerful alternative to transfer these expert skills from human operators to robotic systems. The objective of this study is to systematically map academic publications addressing LfD applications in robotic deburring and polishing between 2016 and 2026, classify the algorithmic structures, sensory modalities, and control configurations employed, and identify key industrial integration challenges. In accordance with the PRISMA 2020 guidelines, a systematic search was conducted across Scopus, Web of Science, IEEE Xplore, and Google Scholar databases. Out of the 288 initially retrieved records, duplicate removal and a two-stage screening process (Title/Abstract review, followed by full-text review) resulted in a final corpus of 24 primary studies included for qualitative synthesis. The included studies were classified into five algorithmic clusters: Dynamic Movement Primitives (DMPs) and variants (9 out of 24 studies, 38%), probabilistic and statistical models (8 out of 24 studies, 33%), deep learning and generative AI architectures (4 out of 24 studies, 17%), autonomous dynamical systems (2 out of 24 studies, 8%), and direct impedance control (1 out of 24 studies, 4%). Force/torque sensing remains the dominant modality; it was utilized exclusively in 71%—17 out of 24—of studies and in 87.5% of studies as any configuration (either as a sole modality or in multimodal setups). However, recent years have documented a trend toward multimodal perception and generative action policies (e.g., Diffusion Policies). The findings suggest that while LfD offers potential cost-reduction and flexibility benefits for small- and medium-sized enterprises (SMEs), technical barriers, such as the sim-to-real transfer gap, high-frequency impact dynamics in deburring, and the autonomous identification of local non-polishing areas (LNP areas), continue to limit widespread industrial deployment. Full article

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22 pages, 15386 KB

Open AccessArticle

Influence of Cutting Wedge Geometry Design on Cutting Forces, Chip Formation and Surface Roughness During Free Machining of Aluminum Alloy

by Norbert Szabó and Gábor Kónya

J. Manuf. Mater. Process. 2026, 10(8), 292; https://doi.org/10.3390/jmmp10080292 - 11 Aug 2026

Viewed by 429

Abstract

This study investigates the effects of the rake angle and clearance angle of custom-manufactured HSS-E Co5 high-speed steel cutting tools on the F_c main cutting force, the F_p passive force component, the Ra and Rz surface roughness parameters, and chip morphology [...] Read more.

This study investigates the effects of the rake angle and clearance angle of custom-manufactured HSS-E Co5 high-speed steel cutting tools on the F_c main cutting force, the F_p passive force component, the Ra and Rz surface roughness parameters, and chip morphology during orthogonal free cutting of EN AW-7075-T6 aluminum alloy. A dedicated experimental fixture was designed and manufactured for the measurements, providing highly accurate depth-of-cut adjustment and ensuring excellent repeatability of the experiments. A full-factorial experimental design was employed, in which the rake angle varied between 0° and 30°, while the clearance angle ranged from 5° to 15°. Three independent cutting trials were performed for each tool geometry. The results showed that increasing the rake angle significantly reduced both the main cutting force (F_c) and the passive force (F_p), whereas increasing the clearance angle resulted in higher force values. Surface roughness analysis revealed that the clearance angle was the dominant factor affecting surface quality. The highest Ra and Rz values were measured at a clearance angle of 15°. Two-way analysis of variance confirmed that the rake angle, the clearance angle, and their interaction had statistically significant effects on the F_c, F_p, Ra, and Rz results. The clearance angle exhibited the strongest effect on F_c, Ra, and Rz, whereas the rake angle had the strongest influence on F_p. Chip morphology observations demonstrated that larger rake angles promoted smoother chip flow and reduced chip compression, while smaller rake angles resulted in thicker and more tightly curled chips. Overall, the combination of larger rake angles and smaller clearance angles provided the most favorable machining conditions, resulting in lower cutting forces, improved chip formation, and enhanced surface quality. Full article

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20 pages, 28930 KB

Open AccessArticle

Effects of Electronic Layout and Beam Design on High-Speed Dynamic Characteristics of FFF 3D Printers

by Wei Xia, Boao Fu, Hanchuan Tong and Qi Tao

J. Manuf. Mater. Process. 2026, 10(8), 291; https://doi.org/10.3390/jmmp10080291 - 10 Aug 2026

Viewed by 288

Abstract

High-speed Fused Filament Fabrication (FFF) printers are prone to nozzle vibration caused by moving-part inertia, frame flexibility, and modal coupling during high-acceleration motion, which can reduce deposition-trajectory stability. This study evaluates the dynamic adaptability of electronics layout and X-axis beam configurations for a [...] Read more.

High-speed Fused Filament Fabrication (FFF) printers are prone to nozzle vibration caused by moving-part inertia, frame flexibility, and modal coupling during high-acceleration motion, which can reduce deposition-trajectory stability. This study evaluates the dynamic adaptability of electronics layout and X-axis beam configurations for a CoreXY FFF printer under complete-machine boundary conditions. A finite element model including the frame, XY motion mechanism, print head, heated bed, and electronics was established. Modal and Y-direction harmonic response analyses were performed by first comparing rear-mounted and bottom-mounted electronics layouts and then by comparing three beam designs. With the baseline beam, both layouts had a first natural frequency of 83 Hz, whereas the rear-mounted layout increased the second- to sixth-order frequencies by 6.8%, 24.2%, 32.0%, 29.2%, and 15.3%. Under the rear-mounted layout, the three beams showed similar first six modal frequencies, but the perforated beam produced the lowest nozzle peak, with a full-band Y-direction response of 0.402 mm, which was 16.1% and 20.4% lower than those of the baseline and hollow square beams, respectively. This beam also had a mass of 41.98 g, which was 45.1% lower than that of the baseline beam. Therefore, rear-mounted electronics combined with a perforated beam was preferred within the current simulation. Full article

(This article belongs to the Special Issue Design, Processes and Materials for Additive Manufacturing: 2nd Edition)

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34 pages, 5222 KB

Open AccessReview

A Critical Review of Assisted Robotic Incremental Sheet Forming of AA5083 Aluminium Alloy: Technical Advances, Industrial Potential and Research Gaps

by Yuvraj Narwade, Sameer Sayyad and Javed Sayyad

J. Manuf. Mater. Process. 2026, 10(8), 290; https://doi.org/10.3390/jmmp10080290 - 8 Aug 2026

Viewed by 440

Abstract

The increasing demand for lightweight and corrosion-resistant structures has accelerated the use of AA5083 aluminium alloy in automotive, aerospace, marine and transportation industries owing to its excellent corrosion resistance, weldability and favourable strength-to-weight ratio. However, the fabrication of complex AA5083 components remains challenging [...] Read more.

The increasing demand for lightweight and corrosion-resistant structures has accelerated the use of AA5083 aluminium alloy in automotive, aerospace, marine and transportation industries owing to its excellent corrosion resistance, weldability and favourable strength-to-weight ratio. However, the fabrication of complex AA5083 components remains challenging because of limited formability, localised thinning, fracture and springback associated with conventional forming processes. Robotic incremental sheet forming (RISF) has emerged as a promising dieless manufacturing technology capable of producing complex and customised components with reduced tooling requirements. Recent developments in assisted RISF, particularly heating-assisted and hydro-assisted approaches, have further enhanced process capability. The reviewed literature consistently demonstrates that heating-assisted RISF improves formability by reducing flow stress and fracture tendency, whereas hydro-assisted RISF provides superior thickness distribution, deformation stability and dimensional accuracy. Despite these advances, significant challenges remain, including the lack of standardised processing conditions, limited comparative studies between cold and assisted RISF, insufficient understanding of hydro-assisted RISF for AA5083, and the absence of comprehensive process–structure–performance correlations. This review critically summarises the principles of ISF, RISF and assisted RISF technologies, evaluates their technical developments, industrial potential and economic considerations, and identifies the major research gaps limiting industrial implementation. Future research should focus on standardised processing methodologies, predictive modelling, integrated process optimisation and comprehensive material characterisation to facilitate the wider adoption of assisted RISF for manufacturing advanced lightweight AA5083 components. Full article

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35 pages, 8759 KB

Open AccessReview

Glass Additive Manufacturing Technologies: Approaches, Applications, and Challenges

by Edwin Francis Cárdenas Correa, Edgar Absalón Torres Barahona and Alison Dayana García Rodríguez

J. Manuf. Mater. Process. 2026, 10(8), 289; https://doi.org/10.3390/jmmp10080289 - 7 Aug 2026

Viewed by 798

Abstract

Glass additive manufacturing (AM) is a developing technology, particularly in comparison to metals and polymers, both of which have had their processes and applications extensively studied. Its potential lies in fabricating complex, even micrometric, geometries that are difficult or impossible to achieve via [...] Read more.

Glass additive manufacturing (AM) is a developing technology, particularly in comparison to metals and polymers, both of which have had their processes and applications extensively studied. Its potential lies in fabricating complex, even micrometric, geometries that are difficult or impossible to achieve via traditional molding, as well as in producing components with unique optical properties. The diversity of AM techniques, alongside the challenges associated with the high melting point, rheological control, and fragility of glass, necessitates a comprehensive analysis of current developments. Accordingly, this review presents a systematic review, conducted in accordance with the PRISMA protocol, of recent literature regarding AM technologies that fabricate glass via particle fusion to form solid components. This review explicitly excludes techniques utilizing glass fibers as reinforcement, as that constitutes a separate field of inquiry. The results demonstrate sustained growth within the field, with a predominance of technologies based on photopolymerization and ink extrusion, both of which offer high resolution and microstructural control. Ultimately, this review establishes the current state of the art, identifying critical challenges and emerging lines of research to guide future development. It is intended to serve as a foundational reference for researchers and professionals seeking to initiate or expand their work in glass AM. Full article

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41 pages, 1971 KB

Open AccessReview

Advanced Surface Protection Strategies for Refurbished Hydropower Components: A Critical Review of Chemical and Manufacturing Approaches

by Gheorghe Daniel Lakatos, Gabriella Stefánia Szabó, Sára Ferenci and Loránd Szabó

J. Manuf. Mater. Process. 2026, 10(8), 288; https://doi.org/10.3390/jmmp10080288 - 7 Aug 2026

Viewed by 550

Abstract

This paper presents a critical review of surface protection strategies for refurbished hydropower components, with emphasis on the manufacturing and materials-processing logic that links damage mechanisms, substrate condition, deposition route, microstructure, and service performance. The literature indicates that cavitation erosion, sediment abrasion, corrosion, [...] Read more.

This paper presents a critical review of surface protection strategies for refurbished hydropower components, with emphasis on the manufacturing and materials-processing logic that links damage mechanisms, substrate condition, deposition route, microstructure, and service performance. The literature indicates that cavitation erosion, sediment abrasion, corrosion, and their synergistic interactions are intensified by flexible and off-design hydropower operation, making refurbishment decisions increasingly surface-sensitive rather than purely bulk-material problems. Thermal spray and laser cladding remain the dominant industrially relevant routes, while cold spray and emerging multi-principal-element, high-entropy, and Fe-based amorphous systems expand the design space for lower heat input, better defect control, and improved cavitation resistance. Across the considered studies, the most consistent conclusion is that hardness alone is not a reliable selection criterion; porosity, interfacial integrity, crack susceptibility, residual stress, and the ability to accommodate local deformation govern real durability. Chemical pre-treatments, sealants, and hybrid finishing routes appear less mature as standalone hydropower solutions, but are important enablers for substrate activation, coating densification, and corrosion mitigation. Therefore, the review proposes a refurbishment-oriented framework in which route selection is based on the initial damage state of the component, the admissible thermal load on the substrate, the required build-up thickness, and the expected cavitation/slurry/corrosion regime. Full article

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25 pages, 7542 KB

Open AccessArticle

Finite Element Simulation of Filling Behaviors in Precision Glass Molding of Fresnel Glass Lenses

by Renwei Gao, Jianmin Tan and Jian Zhou

J. Manuf. Mater. Process. 2026, 10(8), 287; https://doi.org/10.3390/jmmp10080287 - 7 Aug 2026

Viewed by 389

Abstract

Precision glass molding is a promising yet challenging approach for fabricating Fresnel glass lenses, as their complex multi-ring microstructures tend to induce nonuniform glass flow and incomplete filling. To elucidate the filling behaviors under compression, a thermo-mechanically coupled finite element model was developed [...] Read more.

Precision glass molding is a promising yet challenging approach for fabricating Fresnel glass lenses, as their complex multi-ring microstructures tend to induce nonuniform glass flow and incomplete filling. To elucidate the filling behaviors under compression, a thermo-mechanically coupled finite element model was developed to simulate the molding process. The ring filling ratios of each ring and the total lens were adopted as a quantitative metric to systematically investigate the effects of molding temperature, molding pressure, glass–mold interfacial friction coefficient, and the number of Fresnel rings on glass flow and filling behavior. The results show that filling proceeds sequentially from the inner rings to the outer rings. Increasing the interfacial friction coefficient or the number of Fresnel rings significantly increases flow resistance, suppresses radial glass flow, and prolongs the filling time. In contrast, higher molding temperature and pressure promote glass flow, improve the filling efficiency of multi-ring microstructures, and identify the critical processing window for complete filling. These findings provide fundamental insights into the filling behavior of Fresnel microstructures during precision glass molding and offer a theoretical basis for process optimization and the high-precision fabrication of Fresnel lenses. Full article

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28 pages, 7345 KB

Open AccessArticle

MaskLenNet: A Query-Based Instance Segmentation and Length Prediction Network for Quantitative Industrial Tool Wear and Breakage Assessment

by Yi Pan, Kun He, Chen Yin, Yanping Zhang, Yong Luo and Yulin Wang

J. Manuf. Mater. Process. 2026, 10(8), 286; https://doi.org/10.3390/jmmp10080286 - 6 Aug 2026

Viewed by 368

Abstract

Tool wear detection is essential for machining quality control and predictive maintenance, but conventional inspection is often manual, time-consuming, and operator-dependent. Existing learning-based visual methods still face challenges in jointly achieving reliable wear-type recognition, accurate wear-region localization, and quantitative wear-width measurement under shop-floor [...] Read more.

Tool wear detection is essential for machining quality control and predictive maintenance, but conventional inspection is often manual, time-consuming, and operator-dependent. Existing learning-based visual methods still face challenges in jointly achieving reliable wear-type recognition, accurate wear-region localization, and quantitative wear-width measurement under shop-floor imaging conditions. To address these issues, this study proposes MaskLenNet, a query-based instance segmentation and length prediction network for solid carbide end-milling tool diagnosis. MaskLenNet combines a Swin Transformer backbone, query-based instance-mask prediction, wear-oriented attention, and a key-point head that directly estimates the maximum wear-land width (VB). Evaluation uses 234 images from 54 physical tools under a tool-disjoint split, so different rotations of one tool cannot occur in both training and evaluation sets. On the held-out test set, MaskLenNet achieves 96.52% matched-instance classification accuracy, 95.75% foreground instance mIoU, and a VB mean absolute error of 0.010214 mm. Relative to BEiT-Base, the gains are 3.04 and 3.60 percentage points in accuracy and mIoU, respectively. These results demonstrate promising performance within the evaluated acquisition system; they do not establish equivalence to microscopy or generalization to other machines, optics, workpiece materials, or sites. Full article

(This article belongs to the Topic Artificial Intelligence in Smart Industrial Diagnostics and Manufacturing—Third Edition)

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31 pages, 27837 KB

Open AccessArticle

Adaptive Hydrodynamic Cavitation in a Reconfigurable Circular Venturi: Design Framework and Numerical Demonstration of a Parametric Cavitation-Inception Workflow

by Lorenzo Albanese and Federico Rotini

J. Manuf. Mater. Process. 2026, 10(8), 285; https://doi.org/10.3390/jmmp10080285 - 6 Aug 2026

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Abstract

Hydrodynamic cavitation is increasingly investigated as a process-intensification technology for liquid processing and complex or waste-derived streams. Conventional Venturi cavitators rely on fixed geometries selected for nominal operating conditions, whereas practical processes may involve variable fluid properties, flow rates, pressure conditions, and treatment [...] Read more.

Hydrodynamic cavitation is increasingly investigated as a process-intensification technology for liquid processing and complex or waste-derived streams. Conventional Venturi cavitators rely on fixed geometries selected for nominal operating conditions, whereas practical processes may involve variable fluid properties, flow rates, pressure conditions, and treatment objectives. This mismatch can produce unstable cavitation regimes, excessive or insufficient treatment severity, and inefficient use of pressure energy. This article introduces the Dynamic Circular Venturi Adaptive (DCVA), a reconfigurable circular Venturi framework in which the internal profile is treated as an operating variable rather than only as a fixed design feature. Unlike the previously proposed Dynamic Venturi Reuleaux Actuated (DVRA) concept, which uses a non-circular Reuleaux-section Venturi with boundary-imposed swirl, the DCVA retains an axisymmetric circular geometry and relies on controlled profile reconfiguration without swirl forcing. The framework defines equivalent geometric parameters, an admissible design space, plant-measurable operating indicators, and representative architectures for single-parameter and multiparametric reconfiguration. A numerical demonstration of the parametric design workflow is provided using an automated axisymmetric finite-element computational fluid dynamics (CFD) procedure that links CAD generation, meshing, flow simulation, post-processing, and iterative geometry updating to identify the throat configuration associated with cavitation inception. The results support CFD-assisted configuration selection, commissioning-map development, and future supervisory control, while prototype realization and experimental benchmarking remain necessary for full device-level validation. Full article

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20 pages, 19455 KB

Open AccessArticle

Surface Reaction Layer Evolution and Material Removal Mechanism in Chemical-Assisted Magnetorheological Finishing of 316L Stainless Steel Capillaries

by Yefeng Yang, Zhaoyang Luo, Pavel Lushchyk, Bing Guo and Chunya Wu

J. Manuf. Mater. Process. 2026, 10(8), 284; https://doi.org/10.3390/jmmp10080284 - 6 Aug 2026

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Abstract

316L stainless-steel capillary tubes are important in medical devices, precision fluid transport and micro heat exchangers, but their slender geometry and dense passivation film make inner-surface finishing inefficient. This study proposes a stepwise chemical-assisted magnetorheological finishing (CMRF) process for 316L capillaries. The inner [...] Read more.

316L stainless-steel capillary tubes are important in medical devices, precision fluid transport and micro heat exchangers, but their slender geometry and dense passivation film make inner-surface finishing inefficient. This study proposes a stepwise chemical-assisted magnetorheological finishing (CMRF) process for 316L capillaries. The inner surface was first pretreated with hydrogen peroxide/oxalic acid to form a removable reaction layer, and then finished by magnetorheological abrasives. The effects of the two reagents on material removal and surface integrity were evaluated, and the optimal pretreatment was determined to be 2.25 wt.% oxalic acid and 1.5 wt.% H₂O₂. Compared with conventional magnetorheological finishing, CMRF increased the material removal rate by approximately 54% and reduced the final inner-surface roughness Sa to 0.116 μm. Characterization results show that hydrogen peroxide and oxalic acid generate a dynamic oxidation–complexation–dissolution–reoxidation cycle, converting the dense passive film into an oxygen-rich, porous, low-crystallinity reaction layer and reducing surface hardness by about 30%. This softened layer promotes preferential abrasive removal instead of direct cutting of the metallic substrate, thereby improving finishing efficiency and surface quality. Full article

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27 pages, 8401 KB

Open AccessArticle

Influence of Laser Spot Size on the Microstructure, Transformation Temperatures, and Ni Content of a Nickel-Rich LPBF Ti-Ni Alloy

by Alena Kreitcberg, Donatien Campion, Emma Bisserié and Vladimir Brailovski

J. Manuf. Mater. Process. 2026, 10(8), 283; https://doi.org/10.3390/jmmp10080283 - 6 Aug 2026

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Abstract

This study investigates the influence of laser spot size (Ø100 µm vs. Ø50 µm) on the microstructure, transformation behavior, and hardness of Ti-51.17 at.%Ni shape memory alloy samples fabricated by laser powder bed fusion. Samples were produced using identical processing parameters covering laser [...] Read more.

This study investigates the influence of laser spot size (Ø100 µm vs. Ø50 µm) on the microstructure, transformation behavior, and hardness of Ti-51.17 at.%Ni shape memory alloy samples fabricated by laser powder bed fusion. Samples were produced using identical processing parameters covering laser powers of 50–150 W, scanning speeds of 500–750 mm/s, and matched volumetric energy densities (28–83 J/mm³), with spot size as the only variable. Although both laser spot sizes produced comparable melt pool geometries and predominantly B2 austenite matrices with minor fractions of B19′ martensite, the Ø50 µm samples exhibited finer microstructures, higher residual stresses, and lower martensitic transformation temperatures in the as-built state. Heat treatment at 800 °C reduced residual stresses and partially homogenized the microstructure; however, differences in their transformation behavior remained. These differences were attributed to the spot-size-dependent Ni evaporation. Although transformation temperatures increased with increasing energy density for both conditions, the Ø50 µm samples consistently showed lower values. In the 55–83 J/mm³ volumetric energy density range, the estimated Ni content ranged from 51.15 to 50.42 at.%, and the Ø50 µm samples showed approximately 0.1–0.2 at.% greater Ni loss than their Ø100 µm counterparts. These findings demonstrate that Ni evaporation is a laser-spot-size-dependent phenomenon that must be considered when processing near-equiatomic Ti-Ni alloys. Full article

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23 pages, 38482 KB

Open AccessArticle

Substrate-Assisted Binder Jetting of M2 High-Speed Steel: Mechanisms of Printing Defects and Sintering Densification Behavior

by Zilin Huang, Zhanqiang Liu, Jinfu Zhao and Bing Wang

J. Manuf. Mater. Process. 2026, 10(8), 282; https://doi.org/10.3390/jmmp10080282 - 5 Aug 2026

Viewed by 270

Abstract

Binder jetting (BJ) can avoid crack defects caused by residual thermal stress in the additive manufacturing of high-speed steel (HSS). However, the research on BJ-fabricated HSS remains limited and the printing and sintering processes for M2 HSS are still not well understood. The [...] Read more.

Binder jetting (BJ) can avoid crack defects caused by residual thermal stress in the additive manufacturing of high-speed steel (HSS). However, the research on BJ-fabricated HSS remains limited and the printing and sintering processes for M2 HSS are still not well understood. The mechanisms of printing defects and microstructure evolution behavior have not been fully elucidated. In this research, orthogonal experiments are designed and conducted to investigate the effects of layer thickness, inkjet concentration, and powder spreading speed on the forming quality (relative density) of green parts. The types and causes of printing defects are identified and the formation mechanism of layer-shifting defects is analyzed. A method involving an additional printing base is proposed to eliminate layer shifting. An optimized debinding-sintering curve is established and the influence of sintering temperatures (1280–1320 °C) on the relative density, dimensional shrinkage, pore morphology, microstructure, and mechanical properties of BJ M2 HSS is investigated. The transformation mechanisms of carbides are elucidated. The study shows that the BJ M2 HSS achieves a relative density of 99.06% and an average friction coefficient of 0.37 at 1320 °C, with ultimate tensile strength and hardness reaching 858.7 MPa and 628.4 HV. Furthermore, the effects of substrates with different thermal conductivities (graphite and zirconia) on the relative density and warpage of sintered M2 HSS parts are analyzed. The substrates with high thermal conductivity can enhance sintering efficiency but exacerbate deformation. To address this, a graphite-zirconia composite substrate is developed. The results of this study can provide a theoretical foundation for the binder jetting fabrication of high-performance, defect-free M2 HSS. Full article

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21 pages, 7447 KB

Open AccessArticle

Research on the Temperature Control and Protection Effects of Low-Temperature Nitrogen on the Water Jet Cutting Process of Alloy Steel

by Fenglong Yin, Yanxia Li, Xinyi Zhang, Ye Sun and Zehan Li

J. Manuf. Mater. Process. 2026, 10(8), 281; https://doi.org/10.3390/jmmp10080281 - 5 Aug 2026

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Abstract

During abrasive waterjet cutting of alloy steel in complex field environments, local heat sources can induce temperature rise and oxidation risk. To address this issue, this study proposes a low-temperature nitrogen jet (LTNJ) method for simultaneous local cooling and air displacement near the [...] Read more.

During abrasive waterjet cutting of alloy steel in complex field environments, local heat sources can induce temperature rise and oxidation risk. To address this issue, this study proposes a low-temperature nitrogen jet (LTNJ) method for simultaneous local cooling and air displacement near the cutting zone. A three-dimensional fluid-solid coupled heat-transfer and species-transport numerical model was established to investigate the coupled cooling and gas-coverage behavior. The study was further supported by infrared thermal-imaging measurements, in which the measured maximum apparent surface temperature remained within 32.1–33.6 °C during cutting under LTNJ assistance. The simulation results show that a nitrogen-enriched low-oxygen coverage region can be formed above the local heat source; for example, when the local nitrogen volume fraction reaches 64.74%, the estimated oxygen volume fraction decreases to approximately 7.39%. The gas temperature above the heat source decreases by more than 240 °C under the simulated conditions, and the relative position between the nozzle and heat source is the dominant factor affecting local cooling and gas coverage. Considering cooling effect, nitrogen utilization, and field implementation feasibility, the recommended parameter combination within the simulated range is a 10 mm horizontal distance between nozzle axis and heat-source center, a 30 mm vertical distance from nozzle outlet to workpiece surface, an initial nitrogen temperature of −50 °C, and a nitrogen flow rate of 5 m³/h. These results provide a numerical and preliminary experimental basis for low-temperature nitrogen-assisted temperature control and low-oxygen protection during abrasive waterjet cutting in complex field environments. Full article

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J. Manuf. Mater. Process., Volume 10, Issue 8 (August 2026) – 52 articles

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