Pub Date : 2026-01-20DOI: 10.1016/j.jmapro.2026.01.027
Raja Dharavathu , Kishora Shetty , Gopinath Muvvala
Friction stir welding (FSW) is a solid-state joining technique particularly effective for alloys that are difficult to weld by conventional fusion processes. However, welding of thick plates often necessitates robust kinematic systems, and steep thermal gradients can induce high flow stress near the tool tip, leading to tunneling or void defects. This study focuses on minimizing such defects and improving the mechanical performance of 8 mm thick 2014-T6 aluminum alloy joints produced by double-sided FSW. Process optimization was achieved by varying pin lengths, reducing welding speeds, and increasing the tool tilt angle from 0° to 2°, which enhanced plastic flow and material consolidation. Defect-free joints were obtained at welding speeds of 5, 10, and 20 mm/min with a rotational speed of 900 rpm and a 2° tilt angle. Despite the absence of macroscopic defects, the as-welded joints exhibited reduced tensile strength due to overaging and coarsening of Al2Cu precipitates within the nugget zone (NZ), as confirmed by TEM. Comprehensive microstructural characterization using optical microscopy SEM, EDS and EBSD revealed precipitate dissolution and dynamic recrystallization within the NZ. Post-weld heat treatment (PWHT), consisting of solution treatment at 500 °C followed by artificial aging at 160 °C for 18 h, significantly enhanced strength and hardness owing to the re-precipitation of semi-coherent phases, though with a marginal decrease in ductility. Tensile testing with 2D digital image correlation indicated a strain hardening exponent of 0.25 in the as-welded NZ and 0.12 after PWHT, reflecting a transition from localized to more uniform plastic deformation behavior.
{"title":"A study on mitigation of tunneling defects and investigation on the mechanical behavior of double-sided friction stir welded Al 2014 plates","authors":"Raja Dharavathu , Kishora Shetty , Gopinath Muvvala","doi":"10.1016/j.jmapro.2026.01.027","DOIUrl":"10.1016/j.jmapro.2026.01.027","url":null,"abstract":"<div><div>Friction stir welding (FSW) is a solid-state joining technique particularly effective for alloys that are difficult to weld by conventional fusion processes. However, welding of thick plates often necessitates robust kinematic systems, and steep thermal gradients can induce high flow stress near the tool tip, leading to tunneling or void defects. This study focuses on minimizing such defects and improving the mechanical performance of 8 mm thick 2014-T6 aluminum alloy joints produced by double-sided FSW. Process optimization was achieved by varying pin lengths, reducing welding speeds, and increasing the tool tilt angle from 0° to 2°, which enhanced plastic flow and material consolidation. Defect-free joints were obtained at welding speeds of 5, 10, and 20 mm/min with a rotational speed of 900 rpm and a 2° tilt angle. Despite the absence of macroscopic defects, the as-welded joints exhibited reduced tensile strength due to overaging and coarsening of Al<sub>2</sub>Cu precipitates within the nugget zone (NZ), as confirmed by TEM. Comprehensive microstructural characterization using optical microscopy SEM, EDS and EBSD revealed precipitate dissolution and dynamic recrystallization within the NZ. Post-weld heat treatment (PWHT), consisting of solution treatment at 500 °C followed by artificial aging at 160 °C for 18 h, significantly enhanced strength and hardness owing to the re-precipitation of semi-coherent <span><math><msup><mi>θ</mi><mo>′</mo></msup></math></span> phases, though with a marginal decrease in ductility. Tensile testing with 2D digital image correlation indicated a strain hardening exponent of 0.25 in the as-welded NZ and 0.12 after PWHT, reflecting a transition from localized to more uniform plastic deformation behavior.</div></div>","PeriodicalId":16148,"journal":{"name":"Journal of Manufacturing Processes","volume":"159 ","pages":"Pages 460-480"},"PeriodicalIF":6.8,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.jmapro.2026.01.058
Jin Zhang , Taimin Luo , Daixin Luo , Chenjie Deng , Guibao Tao , Huajun Cao
Ultrasonic vibration-assisted milling (UVAM) shows strong potential as an advanced processing technology for the efficient precision machining of carbon-fiber-reinforced-polyetheretherketone (CF/PEEK). Large-amplitude vibrations of 10 to 20 μm create more separation between the tool and workpiece, reducing milling forces and increasing chip removal energy. However, developing large-amplitude and high-efficiency ultrasonic vibration systems remains a challenge for UVAM. To address this, a large-amplitude longitudinal ultrasonic vibration-assisted milling (LALUVAM) toolholder was designed and manufactured in this research. To evaluate this toolholder for milling CF/PEEK with different fiber orientations, milling forces, temperature and surface quality were selected as multidimensional analysis metrics. The findings reveal that the force and temperature are constant at 52 N and 60 °C for a fiber orientation of 45° with a feed speed varying in the range of 600 to 1000 mm/min. The two-dimensional (2D) surface roughness values of machined surfaces with different fiber orientations, when utilizing a 15 μm amplitude ultrasonic toolholder, exhibit considerable variation across different measurement directions and regions. Consequently, it is recommended to employ three-dimensional (3D) surface roughness measurements to more accurately characterize the quality of the machined surfaces. Additionally, the size of the measurement area was found to significantly impact the 3D roughness results for different fiber orientations. Optimal measurement areas were determined to be 640 × 640 μm2 for 0° and 45° fiber orientations, 1200 × 1200 μm2 for the 90° fiber orientation, and 4022 × 640 μm2 for the 135° fiber orientation. Surface defects are observed by scanning electron microscopy (SEM) to explain the cause of surface roughness variation. Moreover, high efficiency and quality milling of UD-CF/PEEK can be realized at a feed speed of 700 mm/min.
{"title":"Surface analysis and assessment in large-amplitude longitudinal ultrasonic vibration-assisted milling of UD-CF/PEEK","authors":"Jin Zhang , Taimin Luo , Daixin Luo , Chenjie Deng , Guibao Tao , Huajun Cao","doi":"10.1016/j.jmapro.2026.01.058","DOIUrl":"10.1016/j.jmapro.2026.01.058","url":null,"abstract":"<div><div>Ultrasonic vibration-assisted milling (UVAM) shows strong potential as an advanced processing technology for the efficient precision machining of carbon-fiber-reinforced-polyetheretherketone (CF/PEEK). Large-amplitude vibrations of 10 to 20 μm create more separation between the tool and workpiece, reducing milling forces and increasing chip removal energy. However, developing large-amplitude and high-efficiency ultrasonic vibration systems remains a challenge for UVAM. To address this, a large-amplitude longitudinal ultrasonic vibration-assisted milling (LALUVAM) toolholder was designed and manufactured in this research. To evaluate this toolholder for milling CF/PEEK with different fiber orientations, milling forces, temperature and surface quality were selected as multidimensional analysis metrics. The findings reveal that the force and temperature are constant at 52 N and 60 °C for a fiber orientation of 45° with a feed speed varying in the range of 600 to 1000 mm/min. The two-dimensional (2D) surface roughness values of machined surfaces with different fiber orientations, when utilizing a 15 μm amplitude ultrasonic toolholder, exhibit considerable variation across different measurement directions and regions. Consequently, it is recommended to employ three-dimensional (3D) surface roughness measurements to more accurately characterize the quality of the machined surfaces. Additionally, the size of the measurement area was found to significantly impact the 3D roughness results for different fiber orientations. Optimal measurement areas were determined to be 640 × 640 μm<sup>2</sup> for 0° and 45° fiber orientations, 1200 × 1200 μm<sup>2</sup> for the 90° fiber orientation, and 4022 × 640 μm<sup>2</sup> for the 135° fiber orientation. Surface defects are observed by scanning electron microscopy (SEM) to explain the cause of surface roughness variation. Moreover, high efficiency and quality milling of UD-CF/PEEK can be realized at a feed speed of 700 mm/min.</div></div>","PeriodicalId":16148,"journal":{"name":"Journal of Manufacturing Processes","volume":"159 ","pages":"Pages 442-459"},"PeriodicalIF":6.8,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.jmapro.2026.01.056
Lin Gu , Kelin Li , Guojian He , Lijie Jiang , Xiaoka Wang
Electrical Arc Machining (EAM) is a promising method for processing difficult-to-cut materials, offering a satisfactory material removal rate and high efficiency. It has been applied in the aerospace industry to remove most of the residue from the blank to save machining time and cost. However, for aerospace parts with complex curved surfaces, such as blades, turbine disks, and impellers, it's prone to lead to intensive working fluid leakage during machining. This fluid leakage adversely recedes the arc breaking effect and results in an unacceptable coarse surface. To address this issue, this study defines the criteria for achieving good machined surface by EAM and proposes the working fluid guiding strategy including internal, external, and combined guiding approaches. The flow field is simulated and a blocker is designed to study the working fluid guiding strategy for the suppression of flushing deficiency. The results indicate that the combined strategy yields the most significant improvement effect, increasing the ratio of effective flushing by 1.2 times and desirable discharge rate by over 35%. Additionally, it noticeably reduces the surface roughness and the thickness of the recast layer. The validity of this novel approach is further demonstrated through the machining of a three-dimensional flow impeller sample using Blasting Erosion Arc Machining (BEAM) with the working fluid guiding strategy.
{"title":"Improving curved surface machining quality of blasting erosion arc milling by applying working fluid blockers","authors":"Lin Gu , Kelin Li , Guojian He , Lijie Jiang , Xiaoka Wang","doi":"10.1016/j.jmapro.2026.01.056","DOIUrl":"10.1016/j.jmapro.2026.01.056","url":null,"abstract":"<div><div>Electrical Arc Machining (EAM) is a promising method for processing difficult-to-cut materials, offering a satisfactory material removal rate and high efficiency. It has been applied in the aerospace industry to remove most of the residue from the blank to save machining time and cost. However, for aerospace parts with complex curved surfaces, such as blades, turbine disks, and impellers, it's prone to lead to intensive working fluid leakage during machining. This fluid leakage adversely recedes the arc breaking effect and results in an unacceptable coarse surface. To address this issue, this study defines the criteria for achieving good machined surface by EAM and proposes the working fluid guiding strategy including internal, external, and combined guiding approaches. The flow field is simulated and a blocker is designed to study the working fluid guiding strategy for the suppression of flushing deficiency. The results indicate that the combined strategy yields the most significant improvement effect, increasing the ratio of effective flushing by 1.2 times and desirable discharge rate by over 35%. Additionally, it noticeably reduces the surface roughness and the thickness of the recast layer. The validity of this novel approach is further demonstrated through the machining of a three-dimensional flow impeller sample using Blasting Erosion Arc Machining (BEAM) with the working fluid guiding strategy.</div></div>","PeriodicalId":16148,"journal":{"name":"Journal of Manufacturing Processes","volume":"160 ","pages":"Pages 1-14"},"PeriodicalIF":6.8,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146001851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-19DOI: 10.1016/j.jmapro.2026.01.019
Shaozhen Hua, Hui Li, Huabo Liu
Unbalanced filling in injection molding of geometrically balanced molds is a bad phenomenon that leads defects and has not been fully understanding. In this work, numerical simulation technique is taken to explore unbalanced filling. The melt during filling is considered to be incompressible, non-isothermal and viscoelastic fluids with Giesekus viscoelastic model to described its rheological character. A coupled finite volume method (FVM) and moving particle simulation (MPS) method was developed. Melt and air flow in cavity are treated as a whole flow field and solved by FVM, while the melt front is captured by the moving particles method. A benchmark case for the MPS method was then used to validate the developed algorithm. Additionally, the melt front progression, gate pressure, temperature distribution, and viscoelastic characteristics during injection molding were simulated and compared to experimental results or other numerical results. Results demonstrate that the developed algorithm can accurately simulate the non-isothermal viscoelastic injection molding process of the melt. Subsequently, the developed algorithm was applied to simulate both balanced and unbalanced filling processes during injection molding. Analysis of shear rate, temperature, and the first and second normal stress differences confirmed the validity of the established theory that shear-induced heating drives unbalanced filling. Furthermore, numerical results demonstrated that in tapered tubular runners, the first normal stress difference promotes balanced flow in naturally balanced runner systems, while the second normal stress difference induces unbalanced filling.
{"title":"Viscoelastic modeling and mechanism analysis of unbalanced filling in geometrically balanced injection molds","authors":"Shaozhen Hua, Hui Li, Huabo Liu","doi":"10.1016/j.jmapro.2026.01.019","DOIUrl":"10.1016/j.jmapro.2026.01.019","url":null,"abstract":"<div><div>Unbalanced filling in injection molding of geometrically balanced molds is a bad phenomenon that leads defects and has not been fully understanding. In this work, numerical simulation technique is taken to explore unbalanced filling. The melt during filling is considered to be incompressible, non-isothermal and viscoelastic fluids with Giesekus viscoelastic model to described its rheological character. A coupled finite volume method (FVM) and moving particle simulation (MPS) method was developed. Melt and air flow in cavity are treated as a whole flow field and solved by FVM, while the melt front is captured by the moving particles method. A benchmark case for the MPS method was then used to validate the developed algorithm. Additionally, the melt front progression, gate pressure, temperature distribution, and viscoelastic characteristics during injection molding were simulated and compared to experimental results or other numerical results. Results demonstrate that the developed algorithm can accurately simulate the non-isothermal viscoelastic injection molding process of the melt. Subsequently, the developed algorithm was applied to simulate both balanced and unbalanced filling processes during injection molding. Analysis of shear rate, temperature, and the first and second normal stress differences confirmed the validity of the established theory that shear-induced heating drives unbalanced filling. Furthermore, numerical results demonstrated that in tapered tubular runners, the first normal stress difference promotes balanced flow in naturally balanced runner systems, while the second normal stress difference induces unbalanced filling.</div></div>","PeriodicalId":16148,"journal":{"name":"Journal of Manufacturing Processes","volume":"159 ","pages":"Pages 409-428"},"PeriodicalIF":6.8,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-19DOI: 10.1016/j.jmapro.2026.01.022
Jian Hu , Hao Shen , Xavier Legrand , Peng Wang
Tufting is a promising technology for reinforcing composite materials, offering notable advantages in both performance and cost-effectiveness. It effectively improves the delamination resistance and impact tolerance of multi-layered composite structures, making it highly applicable across a range of industries, including transportation, construction, energy, and defence. In recent years, significant advancements have been made in the development of tufted multi-layered composites. Nevertheless, there remain gaps in the systematic understanding of the tufting process. This review provides an overview of the current stage of tufting technology, including its definition, key tufting parameters, and the potential damage to tufted composites. Additionally, the paper summarises current research on the forming and simulation of tufted preforms. Future research efforts should focus on optimising the tufting process, standardising techniques, and expanding its industrial applications.
{"title":"A review on tufting technology for 3D preforms: Manufacturing, process parameters and performance implications","authors":"Jian Hu , Hao Shen , Xavier Legrand , Peng Wang","doi":"10.1016/j.jmapro.2026.01.022","DOIUrl":"10.1016/j.jmapro.2026.01.022","url":null,"abstract":"<div><div>Tufting is a promising technology for reinforcing composite materials, offering notable advantages in both performance and cost-effectiveness. It effectively improves the delamination resistance and impact tolerance of multi-layered composite structures, making it highly applicable across a range of industries, including transportation, construction, energy, and defence. In recent years, significant advancements have been made in the development of tufted multi-layered composites. Nevertheless, there remain gaps in the systematic understanding of the tufting process. This review provides an overview of the current stage of tufting technology, including its definition, key tufting parameters, and the potential damage to tufted composites. Additionally, the paper summarises current research on the forming and simulation of tufted preforms. Future research efforts should focus on optimising the tufting process, standardising techniques, and expanding its industrial applications.</div></div>","PeriodicalId":16148,"journal":{"name":"Journal of Manufacturing Processes","volume":"159 ","pages":"Pages 377-395"},"PeriodicalIF":6.8,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-19DOI: 10.1016/j.jmapro.2026.01.048
Peng Han , Jiaxing Duan , Qianzhi Ma , Jia Lin , Fengming Qiang , Wen Wang , Ke Qiao , Kuaishe Wang
To overcome the poor strength-ductility trade-off in ceramic particle-reinforced aluminum matrix composites (AMCs), this study fabricated CoCrFeNi particle-reinforced AMCs using cold spray and cold spray-friction stir processing composite additive manufacturing (CFAM) technology, respectively. The microstructures and mechanical properties of the AMCs were systematically optimized through a short-time T6 heat treatment. A comprehensive microstructural characterization of the AMCs was performed using X-ray diffraction, scanning electron microscopy, electron backscatter diffraction, and transmission electron microscopy. The tensile strength was evaluated and the strengthening mechanism was determined. The results indicated that the cold-sprayed AMCs contained significant porosity and a highly inhomogeneous grain structure. The CoCrFeNi/Al interfaces were primarily characterized by mechanical bonding, with no significant interfacial reactions observed. Comparatively, the AMCs fabricated by CFAM demonstrated significantly refined, homogenized, and densified microstructures, with an average grain size of 1.46 μm. Enhanced elemental interdiffusion occurred at the CoCrFeNi/Al interface, and numerous intermetallic compounds, specifically Al7Cr and Al9(Co,Fe,Ni)2, were found to be homogeneously dispersed within the Al matrix. After short-time T6 heat treatment, the average grain size of the AMCs fabricated by CFAM experienced slight growth, reaching an average of 1.92 μm. Concurrently, interfacial reaction at the CoCrFeNi/Al interface intensified, leading to the formation of a dual-layer interfacial reaction zone. This zone consisted of an inner layer enriched with α-Al(Co,Cr,Fe,Ni)Si and an outer layer enriched with Al9(Co,Fe,Ni)2 and Al13(Co,Fe,Ni)4. Meanwhile, the tensile strength of the AMCs fabricated by CFAM improved by 98 MPa compared to the pre-heat-treated state, reaching 368 MPa. This enhancement was primarily attributed to the short-time T6 heat treatment achieving concurrent optimization of the CoCrFeNi/Al interfacial reaction products and the precipitated phase within the Al matrix, thereby achieving excellent strength and elongation in the AMCs. In summary, this study developed an effective approach for fabricating high-performance AMCs reinforced with CoCrFeNi particles.
{"title":"High-performance CoCrFeNi/6061 aluminum matrix composites fabricated by cold spray-friction stir processing composite additive manufacturing","authors":"Peng Han , Jiaxing Duan , Qianzhi Ma , Jia Lin , Fengming Qiang , Wen Wang , Ke Qiao , Kuaishe Wang","doi":"10.1016/j.jmapro.2026.01.048","DOIUrl":"10.1016/j.jmapro.2026.01.048","url":null,"abstract":"<div><div>To overcome the poor strength-ductility trade-off in ceramic particle-reinforced aluminum matrix composites (AMCs), this study fabricated CoCrFeNi particle-reinforced AMCs using cold spray and cold spray-friction stir processing composite additive manufacturing (CFAM) technology, respectively. The microstructures and mechanical properties of the AMCs were systematically optimized through a short-time T6 heat treatment. A comprehensive microstructural characterization of the AMCs was performed using X-ray diffraction, scanning electron microscopy, electron backscatter diffraction, and transmission electron microscopy. The tensile strength was evaluated and the strengthening mechanism was determined. The results indicated that the cold-sprayed AMCs contained significant porosity and a highly inhomogeneous grain structure. The CoCrFeNi/Al interfaces were primarily characterized by mechanical bonding, with no significant interfacial reactions observed. Comparatively, the AMCs fabricated by CFAM demonstrated significantly refined, homogenized, and densified microstructures, with an average grain size of 1.46 μm. Enhanced elemental interdiffusion occurred at the CoCrFeNi/Al interface, and numerous intermetallic compounds, specifically Al<sub>7</sub>Cr and Al<sub>9</sub>(Co,Fe,Ni)<sub>2</sub>, were found to be homogeneously dispersed within the Al matrix. After short-time T6 heat treatment, the average grain size of the AMCs fabricated by CFAM experienced slight growth, reaching an average of 1.92 μm. Concurrently, interfacial reaction at the CoCrFeNi/Al interface intensified, leading to the formation of a dual-layer interfacial reaction zone. This zone consisted of an inner layer enriched with α-Al(<em>Co</em>,<em>Cr</em>,<em>Fe</em>,<em>Ni</em>)Si and an outer layer enriched with Al<sub>9</sub>(Co,Fe,Ni)<sub>2</sub> and Al<sub>13</sub>(Co,Fe,Ni)<sub>4</sub>. Meanwhile, the tensile strength of the AMCs fabricated by CFAM improved by 98 MPa compared to the pre-heat-treated state, reaching 368 MPa. This enhancement was primarily attributed to the short-time T6 heat treatment achieving concurrent optimization of the CoCrFeNi/Al interfacial reaction products and the precipitated phase within the Al matrix, thereby achieving excellent strength and elongation in the AMCs. In summary, this study developed an effective approach for fabricating high-performance AMCs reinforced with CoCrFeNi particles.</div></div>","PeriodicalId":16148,"journal":{"name":"Journal of Manufacturing Processes","volume":"159 ","pages":"Pages 347-360"},"PeriodicalIF":6.8,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-19DOI: 10.1016/j.jmapro.2026.01.043
Jianbin Zhan , Ruijing Ma , Haodong Wang , Ke Zhu , Shengqian Wang , Liang Zhu , Xuan Liang , Shiyue Guo , Huajun Cao , Kun Li
In NiTi shape-memory alloys, laser powder bed fusion (L-PBF) is used to create spatial microstructural domains, which are jointly controlled by grain size and aging-induced Ni4Ti3 precipitates, allowing a 3D structure to exhibit time-dependent martensitic transformation under stress. This programmable time dependency constitutes 4D printing and enables component-level functional customization. Leveraging this concept, we fabricate a porous NiTi alloy with a high specific cooling capacity for elastocaloric (eC) refrigeration, where two key targets are the specific surface area (S/V) and the force-to-heat conversion ratio (ΔTad/F). These metrics are co-controlled by lattice architecture and microstructure. At the macroscopic scale, four L-PBF lattice designs, strut-based and triply periodic minimal surface (TPMS), are created to tailor the theoretical S/V and ΔTad/F. At the microscopic scale, laser parameters and aging processes modulate grain size and Ni4Ti3 precipitates, tuning the intrinsic eC effect (ΔTad). Results show that single-scale optimization cannot maximize both S/V and ΔTad/F simultaneously. During cooling, the martensite volume fraction (MVF) predominantly governs ΔTad, and its distribution, typically concentrated at pore connections, can be directed by lattice design. Geometry-defined pore morphology and size set stress concentrations, which, together with manufacturing defects under different laser conditions, can trigger premature failure and reduce performance relative to theoretical predictions. A 4D-printing strategy based on the skeletal Gyroid architecture synergistically enhances both metrics, achieving S/V = 12.1 mm−1 and ΔTad/F = 15.7 K·kN−1. These findings provide valuable insights into the manufacturing of lattice-structured NiTi alloys for eC refrigeration.
{"title":"Enhancing the specific cooling capacity of porous elastocaloric NiTi refrigerants via laser 4D printing","authors":"Jianbin Zhan , Ruijing Ma , Haodong Wang , Ke Zhu , Shengqian Wang , Liang Zhu , Xuan Liang , Shiyue Guo , Huajun Cao , Kun Li","doi":"10.1016/j.jmapro.2026.01.043","DOIUrl":"10.1016/j.jmapro.2026.01.043","url":null,"abstract":"<div><div>In NiTi shape-memory alloys, laser powder bed fusion (L-PBF) is used to create spatial microstructural domains, which are jointly controlled by grain size and aging-induced Ni<sub>4</sub>Ti<sub>3</sub> precipitates, allowing a 3D structure to exhibit time-dependent martensitic transformation under stress. This programmable time dependency constitutes 4D printing and enables component-level functional customization. Leveraging this concept, we fabricate a porous NiTi alloy with a high specific cooling capacity for elastocaloric (eC) refrigeration, where two key targets are the specific surface area (<em>S</em>/<em>V</em>) and the force-to-heat conversion ratio (Δ<em>T</em><sub><em>ad</em></sub>/<em>F</em>). These metrics are co-controlled by lattice architecture and microstructure. At the macroscopic scale, four L-PBF lattice designs, strut-based and triply periodic minimal surface (TPMS), are created to tailor the theoretical <em>S</em>/<em>V</em> and Δ<em>T</em><sub><em>ad</em></sub>/<em>F</em>. At the microscopic scale, laser parameters and aging processes modulate grain size and Ni<sub>4</sub>Ti<sub>3</sub> precipitates, tuning the intrinsic eC effect (Δ<em>T</em><sub><em>ad</em></sub>). Results show that single-scale optimization cannot maximize both <em>S</em>/<em>V</em> and Δ<em>T</em><sub><em>ad</em></sub>/<em>F</em> simultaneously. During cooling, the martensite volume fraction (MVF) predominantly governs Δ<em>T</em><sub><em>ad</em></sub>, and its distribution, typically concentrated at pore connections, can be directed by lattice design. Geometry-defined pore morphology and size set stress concentrations, which, together with manufacturing defects under different laser conditions, can trigger premature failure and reduce performance relative to theoretical predictions. A 4D-printing strategy based on the skeletal Gyroid architecture synergistically enhances both metrics, achieving S/V = 12.1 mm<sup>−1</sup> and Δ<em>T</em><sub><em>ad</em></sub>/<em>F</em> = 15.7 K·kN<sup>−1</sup>. These findings provide valuable insights into the manufacturing of lattice-structured NiTi alloys for eC refrigeration.</div></div>","PeriodicalId":16148,"journal":{"name":"Journal of Manufacturing Processes","volume":"159 ","pages":"Pages 361-376"},"PeriodicalIF":6.8,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-19DOI: 10.1016/j.jmapro.2026.01.054
Dongdong Liu , Haojie Zhu, Rui Shen, Fanghong Sun
Conventional diamond powders are mainly industrial diamond powders, typically produced by mechanically crushing methods, which possess irregular, randomly oriented and few edges, causing the lower cutting efficiency and service life. In this paper, uniform and consistently exposed micro-cutting edges were successfully fabricated on conventional diamond powders using hot filament chemical vapor deposition (HFCVD) method. Molecular dynamics (MD) software was used to simulate the multiple-powder scratching on silicon carbide (SiC) ceramics. Scratching simulation results suggest that micro-edge diamond powders produce finer scratch marks, reduce subsurface damage, exhibiting decreased scratching forces and temperatures. The scratching process analysis based on the scratching force results of MD simulation and numerical modeling illustrates that micro-edge diamond powders exert less average pressure on workpiece, resulting in lower material damage. CVD diamond powders under different growth conditions were fabricated by adjusting the deposition parameters, and the hardness of conventional diamond powders, shaped diamond powders and micro-edge diamond powders were compared through indentation tests. Conventional diamond powders undergo film growth, reshaping, micro-edge formation, and slight passivation with a significant reduction in graphite content and enhanced diamond purity as well as hardness throughout CVD growth. The polishing tests are conducted on SiC ceramic workpieces using prepared polishing slurries mixed diamond powders with organic solvents. Polished workpiece achieved a surface roughness value of Sa 4.6 μm reduced to Sa1.3 μm, and the material removal rate reached 4 mm3/min.
{"title":"Molecular dynamics simulation and polishing experimental investigation of CVD micro-edge diamond powders","authors":"Dongdong Liu , Haojie Zhu, Rui Shen, Fanghong Sun","doi":"10.1016/j.jmapro.2026.01.054","DOIUrl":"10.1016/j.jmapro.2026.01.054","url":null,"abstract":"<div><div>Conventional diamond powders are mainly industrial diamond powders, typically produced by mechanically crushing methods, which possess irregular, randomly oriented and few edges, causing the lower cutting efficiency and service life. In this paper, uniform and consistently exposed micro-cutting edges were successfully fabricated on conventional diamond powders using hot filament chemical vapor deposition (HFCVD) method. Molecular dynamics (MD) software was used to simulate the multiple-powder scratching on silicon carbide (SiC) ceramics. Scratching simulation results suggest that micro-edge diamond powders produce finer scratch marks, reduce subsurface damage, exhibiting decreased scratching forces and temperatures. The scratching process analysis based on the scratching force results of MD simulation and numerical modeling illustrates that micro-edge diamond powders exert less average pressure on workpiece, resulting in lower material damage. CVD diamond powders under different growth conditions were fabricated by adjusting the deposition parameters, and the hardness of conventional diamond powders, shaped diamond powders and micro-edge diamond powders were compared through indentation tests. Conventional diamond powders undergo film growth, reshaping, micro-edge formation, and slight passivation with a significant reduction in graphite content and enhanced diamond purity as well as hardness throughout CVD growth. The polishing tests are conducted on SiC ceramic workpieces using prepared polishing slurries mixed diamond powders with organic solvents. Polished workpiece achieved a surface roughness value of Sa 4.6 μm reduced to Sa1.3 μm, and the material removal rate reached 4 mm<sup>3</sup>/min.</div></div>","PeriodicalId":16148,"journal":{"name":"Journal of Manufacturing Processes","volume":"159 ","pages":"Pages 396-408"},"PeriodicalIF":6.8,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-18DOI: 10.1016/j.jmapro.2026.01.055
Ce Xiao , Rongkang Han , Xue Dang , Yichen Han , Jinke Zhang , Pengyu Wang , Jinxin Liu , Yanjin Lu
Laser powder bed fusion (LPBF) processed Ti-1Al-8V-5Fe (Ti-185) alloy presents significant engineering potential as a high-strength, lightweight, and cost-effective beta-Ti titanium alloy. However, compared to LPBF-processed Ti alloys (e.g., Ti-6Al-4V), research on the microstructural and defect formation mechanisms of LPBF-processed Ti-185 alloy, and their effects on mechanical properties, remains limited. Defect analysis via X-ray computed tomography (X-CT) demonstrated that insufficient laser energy density leads to a large number of lack-of-fusion (LOF) defects, whereas excessive laser energy density produces smaller, highly spherical pores. In-situ X-CT tensile tests revealed that with insufficient laser energy, cracks initiate and propagate at the edges of large LOF defects under very small gauge strain, resulting in quasi-brittle fracture, while the high density of pores associated with excessive laser energy accelerates crack propagation, resulting primarily in reduced ductility rather than a decrease in strength. This study provides a comprehensive understanding of the influence of laser energy density on the mechanical behavior of LPBF-processed Ti-185 alloy, offering valuable insights for optimizing processing parameters and expanding its engineering applications.
{"title":"3D characterization of laser energy density effects on mechanical behavior in laser powder bed fused Ti-185 alloy via in-situ X-ray tomography","authors":"Ce Xiao , Rongkang Han , Xue Dang , Yichen Han , Jinke Zhang , Pengyu Wang , Jinxin Liu , Yanjin Lu","doi":"10.1016/j.jmapro.2026.01.055","DOIUrl":"10.1016/j.jmapro.2026.01.055","url":null,"abstract":"<div><div>Laser powder bed fusion (LPBF) processed Ti-1Al-8V-5Fe (Ti-185) alloy presents significant engineering potential as a high-strength, lightweight, and cost-effective beta-Ti titanium alloy. However, compared to <span><math><mrow><mi>α</mi><mo>+</mo><mi>β</mi></mrow></math></span> LPBF-processed Ti alloys (e.g., Ti-6Al-4V), research on the microstructural and defect formation mechanisms of LPBF-processed Ti-185 alloy, and their effects on mechanical properties, remains limited. Defect analysis via X-ray computed tomography (X-CT) demonstrated that insufficient laser energy density leads to a large number of lack-of-fusion (LOF) defects, whereas excessive laser energy density produces smaller, highly spherical pores. In-situ X-CT tensile tests revealed that with insufficient laser energy, cracks initiate and propagate at the edges of large LOF defects under very small gauge strain, resulting in quasi-brittle fracture, while the high density of pores associated with excessive laser energy accelerates crack propagation, resulting primarily in reduced ductility rather than a decrease in strength. This study provides a comprehensive understanding of the influence of laser energy density on the mechanical behavior of LPBF-processed Ti-185 alloy, offering valuable insights for optimizing processing parameters and expanding its engineering applications.</div></div>","PeriodicalId":16148,"journal":{"name":"Journal of Manufacturing Processes","volume":"159 ","pages":"Pages 317-333"},"PeriodicalIF":6.8,"publicationDate":"2026-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-18DOI: 10.1016/j.jmapro.2026.01.044
Guanzhong Hu, Wenpan Li, Rujing Zha, Ping Guo
Directed energy deposition (DED), a metal additive manufacturing process, is highly susceptible to process-induced defects such as geometric deviations, lack of fusion, and poor surface finish. This work presents a build-height-synchronized fringe projection system for in-situ, layer-wise surface reconstruction of laser-DED components, achieving a reconstruction accuracy of . From the reconstructed 3D morphology, two complementary geometry-based point-cloud metrics are introduced: local point density, which highlights poor surface finish, and normal-change rate, which identifies lack-of-fusion features. These methods enable automated, annotation-free identification of common deposition anomalies directly from reconstructed surfaces, without the need for manual labeling. By directly linking geometric deviation to defect formation, the approach enables precise anomaly localization and advances the feasibility of closed-loop process control. This work establishes fringe projection as a practical tool for micrometer-scale monitoring in DED, bridging the gap between process signatures and part geometry for certifiable additive manufacturing.
{"title":"Layer-wise anomaly detection in directed energy deposition using high-fidelity fringe projection profilometry","authors":"Guanzhong Hu, Wenpan Li, Rujing Zha, Ping Guo","doi":"10.1016/j.jmapro.2026.01.044","DOIUrl":"10.1016/j.jmapro.2026.01.044","url":null,"abstract":"<div><div>Directed energy deposition (DED), a metal additive manufacturing process, is highly susceptible to process-induced defects such as geometric deviations, lack of fusion, and poor surface finish. This work presents a build-height-synchronized fringe projection system for in-situ, layer-wise surface reconstruction of laser-DED components, achieving a reconstruction accuracy of <span><math><mrow><mo>±</mo><mtext>46</mtext><mspace></mspace><mtext>µm</mtext></mrow></math></span>. From the reconstructed 3D morphology, two complementary geometry-based point-cloud metrics are introduced: local point density, which highlights poor surface finish, and normal-change rate, which identifies lack-of-fusion features. These methods enable automated, annotation-free identification of common deposition anomalies directly from reconstructed surfaces, without the need for manual labeling. By directly linking geometric deviation to defect formation, the approach enables precise anomaly localization and advances the feasibility of closed-loop process control. This work establishes fringe projection as a practical tool for micrometer-scale monitoring in DED, bridging the gap between process signatures and part geometry for certifiable additive manufacturing.</div></div>","PeriodicalId":16148,"journal":{"name":"Journal of Manufacturing Processes","volume":"159 ","pages":"Pages 334-346"},"PeriodicalIF":6.8,"publicationDate":"2026-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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