Pub Date : 2025-01-27DOI: 10.1016/j.jmatprotec.2025.118748
Pengfei Guo , André Martin , Changshuai Zhai , Zuo Li , Xufei Lu , Jun Yu , Xin Lin , Inger Odnevall , Michael Gibbons , Andreas Schubert
Electrolytic jet machining (EJM) has been widely recognized as one of the effective methods for the surface post-processing of the laser powder bed fusion (LPBF)-components. However, this concept remains challenging due to the limited machining allowance of the LPBF-components and the complexed anodic dissolution behavior, which determine the dimensional accuracy and surface quality of the machined workpiece, respectively. In this work, high current densities ( ≥ 100 A/cm2) are novelly employed to investigate the leveling ratio and transpassive dissolution behavior of LPBF-Inconel 718 for the first time. Compared to 100 A/cm2, 200 A/cm2 improves the leveling ratio to 58.9 % from 57.1 % when the surface roughness is less than 1 µm. However, the high current density up to 200 A/cm2 still cannot inhibit the selective dissolution of the inhomogeneous microstructure, which limits further reduction of the surface roughness. A high current density leads to a rougher micro-surface on horizontal section than low current density, caused by more Nb oxides attached on the horizontal section at high current density generate from continuously distributed Nb-segregation γ phase along the machining depth direction. In addition, the local fine dendrites on vertical section result in a smooth EJM-surface, owing to the relatively uniform dissolution. This investigation provides systematic understanding of leveling process and transpassive dissolution behavior under high current density with complex surface and microstructure, which can further promote synergetic improvements of the surface integrity and dimensional tolerance through controlling the EJM parameters.
{"title":"Effect of current density on electrochemical machining process of laser powder bed fusion manufactured Inconel 718","authors":"Pengfei Guo , André Martin , Changshuai Zhai , Zuo Li , Xufei Lu , Jun Yu , Xin Lin , Inger Odnevall , Michael Gibbons , Andreas Schubert","doi":"10.1016/j.jmatprotec.2025.118748","DOIUrl":"10.1016/j.jmatprotec.2025.118748","url":null,"abstract":"<div><div>Electrolytic jet machining (EJM) has been widely recognized as one of the effective methods for the surface post-processing of the laser powder bed fusion (LPBF)-components. However, this concept remains challenging due to the limited machining allowance of the LPBF-components and the complexed anodic dissolution behavior, which determine the dimensional accuracy and surface quality of the machined workpiece, respectively. In this work, high current densities ( ≥ 100 A/cm<sup>2</sup>) are novelly employed to investigate the leveling ratio and transpassive dissolution behavior of LPBF-Inconel 718 for the first time. Compared to 100 A/cm<sup>2</sup>, 200 A/cm<sup>2</sup> improves the leveling ratio to 58.9 % from 57.1 % when the surface roughness is less than 1 µm. However, the high current density up to 200 A/cm<sup>2</sup> still cannot inhibit the selective dissolution of the inhomogeneous microstructure, which limits further reduction of the surface roughness. A high current density leads to a rougher micro-surface on horizontal section than low current density, caused by more Nb oxides attached on the horizontal section at high current density generate from continuously distributed Nb-segregation γ phase along the machining depth direction. In addition, the local fine dendrites on vertical section result in a smooth EJM-surface, owing to the relatively uniform dissolution. This investigation provides systematic understanding of leveling process and transpassive dissolution behavior under high current density with complex surface and microstructure, which can further promote synergetic improvements of the surface integrity and dimensional tolerance through controlling the EJM parameters.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"337 ","pages":"Article 118748"},"PeriodicalIF":6.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-27DOI: 10.1016/j.jmatprotec.2025.118743
Huaixin Lin , Gang Jin , Xiaofan Deng , Zhanjie Li , Yuanhao Ma , Guangyu Wang , Feifan Hou , Shaokun Luo
The drilling of thin-walled parts often encounters serious issues, such as low machining dimensional and geometric accuracy, thus compromising the integrity of the hole wall surface and subsurface layer. These issues are major constraints in achieving high-quality and high-precision manufacturing in aerospace and other industries. This study proposes an innovative ice-coated drilling (ICD) method for thin-walled parts and delves into the discussion of its machining mechanism. Four typical aerospace materials with thin-walled parts were selected as the research objects. The influence of different processing methods on machining quality was comprehensively evaluated by comparing and analyzing the performance of traditional drilling (TD) and ICD in terms of the flatness, parallelism, roundness, diameter error, axial force, torque, hole wall, and chip morphology of the hole. Results show that ICD remarkably improves the flatness and parallelism of the four thin-walled parts through the cooling effect and auxiliary support function of the ice layer, and it optimizes the roundness and diameter error of the hole. Moreover, the hole wall is smooth without defects, the height of the outlet burr is greatly reduced, and the overall machining quality is remarkably improved. In addition, the presence of the ice layer not only reduces axial forces and torque but also enhances residual compressive stress. The effects of different machining methods on cutting temperature were further analyzed, and the mechanism of ICD to suppress the heat-affected zone (HAZ) was elucidated. This study provides a novel and efficient solution to the challenges of machining thin-walled parts in manufacturing fields, such as aerospace.
{"title":"Investigation on the machining mechanism and quality of an ice-coated drilling method for thin-walled parts","authors":"Huaixin Lin , Gang Jin , Xiaofan Deng , Zhanjie Li , Yuanhao Ma , Guangyu Wang , Feifan Hou , Shaokun Luo","doi":"10.1016/j.jmatprotec.2025.118743","DOIUrl":"10.1016/j.jmatprotec.2025.118743","url":null,"abstract":"<div><div>The drilling of thin-walled parts often encounters serious issues, such as low machining dimensional and geometric accuracy, thus compromising the integrity of the hole wall surface and subsurface layer. These issues are major constraints in achieving high-quality and high-precision manufacturing in aerospace and other industries. This study proposes an innovative ice-coated drilling (ICD) method for thin-walled parts and delves into the discussion of its machining mechanism. Four typical aerospace materials with thin-walled parts were selected as the research objects. The influence of different processing methods on machining quality was comprehensively evaluated by comparing and analyzing the performance of traditional drilling (TD) and ICD in terms of the flatness, parallelism, roundness, diameter error, axial force, torque, hole wall, and chip morphology of the hole. Results show that ICD remarkably improves the flatness and parallelism of the four thin-walled parts through the cooling effect and auxiliary support function of the ice layer, and it optimizes the roundness and diameter error of the hole. Moreover, the hole wall is smooth without defects, the height of the outlet burr is greatly reduced, and the overall machining quality is remarkably improved. In addition, the presence of the ice layer not only reduces axial forces and torque but also enhances residual compressive stress. The effects of different machining methods on cutting temperature were further analyzed, and the mechanism of ICD to suppress the heat-affected zone (HAZ) was elucidated. This study provides a novel and efficient solution to the challenges of machining thin-walled parts in manufacturing fields, such as aerospace.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"337 ","pages":"Article 118743"},"PeriodicalIF":6.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-27DOI: 10.1016/j.jmatprotec.2025.118745
Ziqin Yan , Wei Wen , Hanpeng Wang , Chuan Zhou , Guang Yang , Rui Li , Lihua Zhan , Xiaohui Cui , Ang Xiao
Electromagnetic forming is a high strain rate forming method, which can significantly increase the forming limit of aluminium alloy. However, there are two problems in the process of hole flanging: (1) sheet needs prefabricated holes, which usually obtained by blanking process. (2) Different shapes of parts need different coil structures; Therefore, the forming process is complicated and the cost is high. Hence, this paper introduces an high strain rate forming method called electromagnetic hydraulic blanking flanging (EMHBF) integrated process. This process combines blanking and flanging in one device, can meet the flanging parts of various shapes and sizes under the condition of not replacing the coil, simplifying the process and reducing the production cost. A multi-physical field coupling model, encompassing electromagnetic and fluid-solid interactions, is also developed to explore changes in liquid flow patterns and the stress state of sheet metal. The influence of die structure (by changing the angle parameters of the die structure, the liquid flow direction can be regulated), discharge voltage, sheet thickness, and flanging part shape on EMHBF forming results is investigated. Variations in die structure lead to differing distributions of liquid pressure on the sheet’s upper and lower surfaces, altering liquid flow patterns and enhancing the sheet’s forming accuracy. An increase in voltage increases the sheet thickness shear stress and blanking velocity, consequently decreasing the blanking burr height. The simulated maximum forming height error was less than 9.0 %, and the maximum thickness error was less than 5.3 %. The EMHBF can meet the needs of different thicknesses and flanging part shapes for a discharge voltage of 8.5 kV. Therefore, this article provides reference rules for designing an EMHBF process. The flanging parts with high forming accuracy can be obtained in the EMHBF device by optimizing the process parameters. The essence of the EMHBF process is guiding the high-pressure and high-speed fluid movement on demand by changing the die structure and discharge voltage. In the future, EMHBF will not be limited to blanking and flanging. The blanking and other sheet deformation behavior can be achieved if the die is designed reasonably.
{"title":"Electromagnetic hydraulic blanking flanging integrated process","authors":"Ziqin Yan , Wei Wen , Hanpeng Wang , Chuan Zhou , Guang Yang , Rui Li , Lihua Zhan , Xiaohui Cui , Ang Xiao","doi":"10.1016/j.jmatprotec.2025.118745","DOIUrl":"10.1016/j.jmatprotec.2025.118745","url":null,"abstract":"<div><div>Electromagnetic forming is a high strain rate forming method, which can significantly increase the forming limit of aluminium alloy. However, there are two problems in the process of hole flanging: (1) sheet needs prefabricated holes, which usually obtained by blanking process. (2) Different shapes of parts need different coil structures; Therefore, the forming process is complicated and the cost is high. Hence, this paper introduces an high strain rate forming method called electromagnetic hydraulic blanking flanging (EMHBF) integrated process. This process combines blanking and flanging in one device, can meet the flanging parts of various shapes and sizes under the condition of not replacing the coil, simplifying the process and reducing the production cost. A multi-physical field coupling model, encompassing electromagnetic and fluid-solid interactions, is also developed to explore changes in liquid flow patterns and the stress state of sheet metal. The influence of die structure (by changing the angle parameters of the die structure, the liquid flow direction can be regulated), discharge voltage, sheet thickness, and flanging part shape on EMHBF forming results is investigated. Variations in die structure lead to differing distributions of liquid pressure on the sheet’s upper and lower surfaces, altering liquid flow patterns and enhancing the sheet’s forming accuracy. An increase in voltage increases the sheet thickness shear stress and blanking velocity, consequently decreasing the blanking burr height. The simulated maximum forming height error was less than 9.0 %, and the maximum thickness error was less than 5.3 %. The EMHBF can meet the needs of different thicknesses and flanging part shapes for a discharge voltage of 8.5 kV. Therefore, this article provides reference rules for designing an EMHBF process. The flanging parts with high forming accuracy can be obtained in the EMHBF device by optimizing the process parameters. The essence of the EMHBF process is guiding the high-pressure and high-speed fluid movement on demand by changing the die structure and discharge voltage. In the future, EMHBF will not be limited to blanking and flanging. The blanking and other sheet deformation behavior can be achieved if the die is designed reasonably.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"337 ","pages":"Article 118745"},"PeriodicalIF":6.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-25DOI: 10.1016/j.jmatprotec.2025.118746
Junqi Zhang , Zhixian Chen , Zejin Zhan , Yongjie Zhang , Bing Wu , Yinhui Wang , Hui Deng
Due to the advantages of high efficiency, low cost and versatile operation, atmospheric plasma machining has drawn significant attention in the field of semiconductor and optical fabrication. Nevertheless, for conventional atmospheric plasma machining sources feature low temperature, the machining efficiency is limited due to the low gas ionization rate. This paper presents a novel double ignition strategy based on coupled coupling plasma (CCP) for enhanced radical concentration and machining efficiency. The double ignition plasma jet (DIPJ) enhances electron concentration and promotes the dissociation of fluorine radicals compared to single ignition plasma jet (SIPJ), exhibiting higher removal efficiency. Afterwards, the jet characteristics are significantly affected by regulating the electric field distribution of DIPJ through adjusting the structural parameters, which further promotes the ignition strength and radical generation. With the optimization of ignition configuration and process parameters, a Gaussian removal function can be obtained and the material removal rate (MRR) can be reached over 0.4 mm3/min at a full width at half maximum (FWHM) of 4.8 mm. The form error of a 100 × 50 mm2 Si planar mirror can be reduced from 150.41 nm to 19.36 nm RMS within 7.9 min after one iteration of figuring, which demonstrates the high processing efficiency optical manufacturing.
{"title":"A double ignition strategy for enhanced efficiency in atmospheric plasma machining","authors":"Junqi Zhang , Zhixian Chen , Zejin Zhan , Yongjie Zhang , Bing Wu , Yinhui Wang , Hui Deng","doi":"10.1016/j.jmatprotec.2025.118746","DOIUrl":"10.1016/j.jmatprotec.2025.118746","url":null,"abstract":"<div><div>Due to the advantages of high efficiency, low cost and versatile operation, atmospheric plasma machining has drawn significant attention in the field of semiconductor and optical fabrication. Nevertheless, for conventional atmospheric plasma machining sources feature low temperature, the machining efficiency is limited due to the low gas ionization rate. This paper presents a novel double ignition strategy based on coupled coupling plasma (CCP) for enhanced radical concentration and machining efficiency. The double ignition plasma jet (DIPJ) enhances electron concentration and promotes the dissociation of fluorine radicals compared to single ignition plasma jet (SIPJ), exhibiting higher removal efficiency. Afterwards, the jet characteristics are significantly affected by regulating the electric field distribution of DIPJ through adjusting the structural parameters, which further promotes the ignition strength and radical generation. With the optimization of ignition configuration and process parameters, a Gaussian removal function can be obtained and the material removal rate (MRR) can be reached over 0.4 mm<sup>3</sup>/min at a full width at half maximum (FWHM) of 4.8 mm. The form error of a 100 × 50 mm<sup>2</sup> Si planar mirror can be reduced from 150.41 nm to 19.36 nm RMS within 7.9 min after one iteration of figuring, which demonstrates the high processing efficiency optical manufacturing.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"337 ","pages":"Article 118746"},"PeriodicalIF":6.7,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-25DOI: 10.1016/j.jmatprotec.2025.118744
Pengcheng Zhao , Bin Lin , Jingguo Zhou , Bingrui Lv , Jinming Li , Jinshuo Zhang , Longfei Wang , Tianyi Sui
Green and intelligent manufacturing has become a key development trend in the industrial sector. Grinding as a widely used machining process, advancing towards greener and smarter practices. Grinding generates significant heat, which critically affects the processed material. Therefore, accurately measuring and controlling the grinding temperature has become increasingly important. Various principles and numerous grinding temperature models have been proposed to address this challenge. This review provides a comprehensive analysis of the development of grinding temperature measurement technologies, tracing their evolution from traditional methods to modern techniques, and from foundational principles to practical applications. It elaborates on diverse measurement methods, including direct and indirect techniques, and compares these methods in terms of measurement accuracy, response speed, application scope, and operational complexity. The advantages and limitations of each technology are highlighted. Additionally, the key factors influencing the accuracy of grinding temperature measurements are discussed, along with strategies to address the shortcomings of existing methods through technological innovation. This review consolidates existing research and proposes directions for future advancements in grinding temperature measurement technologies to support intelligent manufacturing and high-performance manufacturing.
{"title":"Review of grinding temperature theory and measurement for the needs of the times: Promoting the development of advanced manufacturing","authors":"Pengcheng Zhao , Bin Lin , Jingguo Zhou , Bingrui Lv , Jinming Li , Jinshuo Zhang , Longfei Wang , Tianyi Sui","doi":"10.1016/j.jmatprotec.2025.118744","DOIUrl":"10.1016/j.jmatprotec.2025.118744","url":null,"abstract":"<div><div>Green and intelligent manufacturing has become a key development trend in the industrial sector. Grinding as a widely used machining process, advancing towards greener and smarter practices. Grinding generates significant heat, which critically affects the processed material. Therefore, accurately measuring and controlling the grinding temperature has become increasingly important. Various principles and numerous grinding temperature models have been proposed to address this challenge. This review provides a comprehensive analysis of the development of grinding temperature measurement technologies, tracing their evolution from traditional methods to modern techniques, and from foundational principles to practical applications. It elaborates on diverse measurement methods, including direct and indirect techniques, and compares these methods in terms of measurement accuracy, response speed, application scope, and operational complexity. The advantages and limitations of each technology are highlighted. Additionally, the key factors influencing the accuracy of grinding temperature measurements are discussed, along with strategies to address the shortcomings of existing methods through technological innovation. This review consolidates existing research and proposes directions for future advancements in grinding temperature measurement technologies to support intelligent manufacturing and high-performance manufacturing.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"337 ","pages":"Article 118744"},"PeriodicalIF":6.7,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-24DOI: 10.1016/j.jmatprotec.2025.118747
Dexin Zhang, Yi Xiao, Can Li, Tianwen Zhao, Huiqiao Du, Yong Li
The high-performance joining of copper alloy and nickel-based superalloy to achieve high wear resistance, thermal conductivity and stiffness in the same structure is attracting increasing interest in various industries. However, directly joining to obtain high-quality joints of these two dissimilar materials is a challenge due to the significant differences in physical and chemical properties. In this study, a novel solid-state diffusion bonding method by employing isostatic high pressure has been proposed. The process parameters are optimized to achieve high-quality joints of a new material system (CuAgZn and GH600). The effects of bonding temperatures on microstructure evolution and mechanical properties at the joints under high-pressure conditions have been systematically investigated. The results show that reliable metallurgical joints, free of defects, have been successfully obtained under high isostatic pressure of 170 MPa, and some solid solution and precipitated phases have formed at the interface. The joint has exhibited a maximum tensile strength of 280.9 MPa (about 80 % of the copper alloy) with the bonding temperature of 660 °C. All the joints fractured adjacent to CuAgZn and exhibited brittle fracture features with ductile characteristics after tensile tests. Solution strengthening, precipitation strengthening, and recrystallization softening have been explained as the main mechanisms for the good joint strength. This study provides an effective strategy for achieving high-quality joints by isostatic high-pressure diffusion bonding for dissimilar materials.
{"title":"Achieving high-quality copper alloy to nickel-based superalloy joint by isostatic high-pressure solid-state diffusion bonding","authors":"Dexin Zhang, Yi Xiao, Can Li, Tianwen Zhao, Huiqiao Du, Yong Li","doi":"10.1016/j.jmatprotec.2025.118747","DOIUrl":"10.1016/j.jmatprotec.2025.118747","url":null,"abstract":"<div><div>The high-performance joining of copper alloy and nickel-based superalloy to achieve high wear resistance, thermal conductivity and stiffness in the same structure is attracting increasing interest in various industries. However, directly joining to obtain high-quality joints of these two dissimilar materials is a challenge due to the significant differences in physical and chemical properties. In this study, a novel solid-state diffusion bonding method by employing isostatic high pressure has been proposed. The process parameters are optimized to achieve high-quality joints of a new material system (CuAgZn and GH600). The effects of bonding temperatures on microstructure evolution and mechanical properties at the joints under high-pressure conditions have been systematically investigated. The results show that reliable metallurgical joints, free of defects, have been successfully obtained under high isostatic pressure of 170 MPa, and some solid solution and precipitated phases have formed at the interface. The joint has exhibited a maximum tensile strength of 280.9 MPa (about 80 % of the copper alloy) with the bonding temperature of 660 °C. All the joints fractured adjacent to CuAgZn and exhibited brittle fracture features with ductile characteristics after tensile tests. Solution strengthening, precipitation strengthening, and recrystallization softening have been explained as the main mechanisms for the good joint strength. This study provides an effective strategy for achieving high-quality joints by isostatic high-pressure diffusion bonding for dissimilar materials.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"337 ","pages":"Article 118747"},"PeriodicalIF":6.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-22DOI: 10.1016/j.jmatprotec.2025.118742
Xiaowei Wang , Zhaoyang Yan , Tao Zhao , Yu Dong , Shujun Chen , Huijun Li
In this study, the heat and mass transfer processes of wire-arc directed energy deposition were investigated by introducing the concept of the additive units ordering stack. The relationship between the process parameters and formed dimensions was used to accurately predict the critical height of thermal equilibrium and establish process schemes to achieve thermal balance. A 2319 Al alloy part having fully equiaxed grains was fabricated. The impact of thermal equilibrium on the forming precision, microstructure, and mechanical properties was examined. After thermal equilibrium was achieved, the dimensions of the deposited layers stabilized, with a volumetric removal rate indicating a forming accuracy of 0.22 %, which was significantly better than the accuracy of 3.02 % achieved in non-equilibrium zones. The porosity-distribution density decreased, and the average hardness values exhibited a low standard deviation of approximately ±5.46 HV0.2. Thermal-equilibrium conditions optimized the mushy zone, leading to a uniform equiaxed microstructure with an average grain size of 44.2 μm and minimal size deviation between adjacent axial grains. Thermal equilibrium mitigated the effects of temperature differences on Cu atom diffusion, enhanced the microstructural uniformity, and achieved a tensile-strength consistency of 99.4 % in all directions, with average tensile strengths of 182.3 ± 0.9 and 183.33 ± 1.3 MPa in the transverse and longitudinal directions, respectively. This approach represents a fundamental advancement in achieving thermal equilibrium during the deposition process, offering new insights for improving forming accuracy and performance anisotropy.
{"title":"Grain structure and microstructural properties of 2139 Al alloy based on additive units ordering stack via wire-arc directed energy deposition","authors":"Xiaowei Wang , Zhaoyang Yan , Tao Zhao , Yu Dong , Shujun Chen , Huijun Li","doi":"10.1016/j.jmatprotec.2025.118742","DOIUrl":"10.1016/j.jmatprotec.2025.118742","url":null,"abstract":"<div><div>In this study, the heat and mass transfer processes of wire-arc directed energy deposition were investigated by introducing the concept of the additive units ordering stack. The relationship between the process parameters and formed dimensions was used to accurately predict the critical height of thermal equilibrium and establish process schemes to achieve thermal balance. A 2319 Al alloy part having fully equiaxed grains was fabricated. The impact of thermal equilibrium on the forming precision, microstructure, and mechanical properties was examined. After thermal equilibrium was achieved, the dimensions of the deposited layers stabilized, with a volumetric removal rate indicating a forming accuracy of 0.22 %, which was significantly better than the accuracy of 3.02 % achieved in non-equilibrium zones. The porosity-distribution density decreased, and the average hardness values exhibited a low standard deviation of approximately ±5.46 HV<sub>0.2</sub>. Thermal-equilibrium conditions optimized the mushy zone, leading to a uniform equiaxed microstructure with an average grain size of 44.2 μm and minimal size deviation between adjacent axial grains. Thermal equilibrium mitigated the effects of temperature differences on Cu atom diffusion, enhanced the microstructural uniformity, and achieved a tensile-strength consistency of 99.4 % in all directions, with average tensile strengths of 182.3 ± 0.9 and 183.33 ± 1.3 MPa in the transverse and longitudinal directions, respectively. This approach represents a fundamental advancement in achieving thermal equilibrium during the deposition process, offering new insights for improving forming accuracy and performance anisotropy.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"337 ","pages":"Article 118742"},"PeriodicalIF":6.7,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-22DOI: 10.1016/j.jmatprotec.2025.118739
Yang Yang, Han Pan, Yuchao Bai, Yingxue Yao
Vibration-assisted diamond texturing (VADT) has recently gained prominence as an effective method for producing micro- and nanostructured functional surfaces, offering considerable application potential. Despite its advantages, the accuracy of surface formation in VADT, governed by the replication of cutting trajectories, must contend with the unavoidable inaccuracies inherent in the manufacturing systems. To address this issue and enhance the process robustness, this paper firstly proposes a novel adaptive diamond texturing approach that integrates a hybrid control of the 2D tool position and cutting force to precisely track the desired material removal state. A bidirectional mapping relationship between the actual cutting trajectory and dynamic cutting force has been established, enabling real-time decoupling of the transient material removal state. Furthermore, an objective function for optimal 2D tool compensation displacement has been analytically defined to track the desired cutting force and surface topography adaptively. Experimental validations conducted on freeform and inclined surfaces demonstrate the high consistency of the textured microstructures and precise tracking of the desired material removal state and 2D cutting force. Additionally, this paper highlights the superiority of the proposed hybrid control approach over conventional tool position-based and thrust force-based servo controls. This study advances the scientific understandings of the surface formation principle and the significant impacts of tool servo position and machining system errors on dynamic cutting force in VADT processes. It also explores the potential of force servo-based control methodologies to enhance process robustness, independent of manufacturing system errors and the characteristics of cutting force.
{"title":"Adaptive diamond texturing of micro/nano-structured surfaces enabled by hybrid control of 2D tool position and cutting force","authors":"Yang Yang, Han Pan, Yuchao Bai, Yingxue Yao","doi":"10.1016/j.jmatprotec.2025.118739","DOIUrl":"10.1016/j.jmatprotec.2025.118739","url":null,"abstract":"<div><div>Vibration-assisted diamond texturing (VADT) has recently gained prominence as an effective method for producing micro- and nanostructured functional surfaces, offering considerable application potential. Despite its advantages, the accuracy of surface formation in VADT, governed by the replication of cutting trajectories, must contend with the unavoidable inaccuracies inherent in the manufacturing systems. To address this issue and enhance the process robustness, this paper firstly proposes a novel adaptive diamond texturing approach that integrates a hybrid control of the 2D tool position and cutting force to precisely track the desired material removal state. A bidirectional mapping relationship between the actual cutting trajectory and dynamic cutting force has been established, enabling real-time decoupling of the transient material removal state. Furthermore, an objective function for optimal 2D tool compensation displacement has been analytically defined to track the desired cutting force and surface topography adaptively. Experimental validations conducted on freeform and inclined surfaces demonstrate the high consistency of the textured microstructures and precise tracking of the desired material removal state and 2D cutting force. Additionally, this paper highlights the superiority of the proposed hybrid control approach over conventional tool position-based and thrust force-based servo controls. This study advances the scientific understandings of the surface formation principle and the significant impacts of tool servo position and machining system errors on dynamic cutting force in VADT processes. It also explores the potential of force servo-based control methodologies to enhance process robustness, independent of manufacturing system errors and the characteristics of cutting force.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"337 ","pages":"Article 118739"},"PeriodicalIF":6.7,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-20DOI: 10.1016/j.jmatprotec.2025.118738
Florian Pixner , Aurel Arnoldt , Michael Unger , Christian Schneider-Bröskamp , Kamalesh Bharadwaj , Florian Mayrhofer , Rudolf Gradinger , Thomas Klein
Additively manufactured stainless steel structures are produced under different shielding gas atmospheres, namely inert argon blended with variants in the composition of nitrogen and helium. The present study investigates the concept of in-situ interstitial nitrogen alloying via the shielding gas atmosphere in arc- and wire-based directed energy deposition of austenitic chromium-nickel stainless steel. A comparable deposition- and build-up characteristic was observed for all deposits, irrespective of the shielding gas used. A slight increase in spatter formation and a marginal reduction in average layer height was observed when the helium content was increased. The chemical composition of the deposits can be actively influenced by the shielding gas atmosphere: Addition of nitrogen to the shielding gas atmosphere directly increases the nitrogen content in the deposits produced and thus changes the microstructure and the corresponding mechanical properties. With increasing nitrogen content, the primary solidification mode changes from ferritic-austenitic to austenitic-ferritic to almost pure austenite. Deposits fabricated with pure argon inert gas atmosphere show a dual-phase microstructure with a considerable amount of vermicular delta-ferrite embedded in the secondary austenitic-matrix, while the addition of nitrogen changes the microstructure to primary columnar/cellular grown austenite dendrites with lath-shaped secondary delta-ferrite embedded in the interdendritic zones; the proportion of lath-shaped delta-ferrite decreases with increasing nitrogen content. Helium addition to the nitrogen in the shielding atmosphere leads to a further refinement of the columnar/cellular grown primary austenite dendrites. The changes in the chemical composition and microstructure are also reflected in the associated mechanical properties. In-situ alloying of nitrogen acts as interstitial solid solution strengthening and increases the tensile strength, the strain-hardening rate, though reduces the fracture strain compared to deposits produced under pure argon atmosphere. By adding helium and due to its refining effect, the fracture strain can be fully recovered. Nevertheless, the strengthening effect of nitrogen is also limited, and excessive nitrogen alloying and interstitial solid solution strengthening leads to premature failure and fully brittle fracture of the excessively nitrogen alloyed specimens.
{"title":"On the viability of in-situ alloying via process gas mixtures in wire arc directed energy deposition of austenitic stainless steel","authors":"Florian Pixner , Aurel Arnoldt , Michael Unger , Christian Schneider-Bröskamp , Kamalesh Bharadwaj , Florian Mayrhofer , Rudolf Gradinger , Thomas Klein","doi":"10.1016/j.jmatprotec.2025.118738","DOIUrl":"10.1016/j.jmatprotec.2025.118738","url":null,"abstract":"<div><div>Additively manufactured stainless steel structures are produced under different shielding gas atmospheres, namely inert argon blended with variants in the composition of nitrogen and helium. The present study investigates the concept of in-situ interstitial nitrogen alloying via the shielding gas atmosphere in arc- and wire-based directed energy deposition of austenitic chromium-nickel stainless steel. A comparable deposition- and build-up characteristic was observed for all deposits, irrespective of the shielding gas used. A slight increase in spatter formation and a marginal reduction in average layer height was observed when the helium content was increased. The chemical composition of the deposits can be actively influenced by the shielding gas atmosphere: Addition of nitrogen to the shielding gas atmosphere directly increases the nitrogen content in the deposits produced and thus changes the microstructure and the corresponding mechanical properties. With increasing nitrogen content, the primary solidification mode changes from ferritic-austenitic to austenitic-ferritic to almost pure austenite. Deposits fabricated with pure argon inert gas atmosphere show a dual-phase microstructure with a considerable amount of vermicular delta-ferrite embedded in the secondary austenitic-matrix, while the addition of nitrogen changes the microstructure to primary columnar/cellular grown austenite dendrites with lath-shaped secondary delta-ferrite embedded in the interdendritic zones; the proportion of lath-shaped delta-ferrite decreases with increasing nitrogen content. Helium addition to the nitrogen in the shielding atmosphere leads to a further refinement of the columnar/cellular grown primary austenite dendrites. The changes in the chemical composition and microstructure are also reflected in the associated mechanical properties. In-situ alloying of nitrogen acts as interstitial solid solution strengthening and increases the tensile strength, the strain-hardening rate, though reduces the fracture strain compared to deposits produced under pure argon atmosphere. By adding helium and due to its refining effect, the fracture strain can be fully recovered. Nevertheless, the strengthening effect of nitrogen is also limited, and excessive nitrogen alloying and interstitial solid solution strengthening leads to premature failure and fully brittle fracture of the excessively nitrogen alloyed specimens.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"337 ","pages":"Article 118738"},"PeriodicalIF":6.7,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding the role of grain morphology in the chip formation mechanism during orthogonal cutting is crucial to achieve reliable surface integrity. This is especially important when machining additively manufactured alloys due to the inherent presence of crystallographic textures from their unique grain growth patterns. In this work, wrought and laser powder bed fusion (LPBF) fabricated Alloy 718, representing equiaxed and elongated grains respectively, were employed as the case studies to investigate the influence of grain morphology on the chip formation. A new customised Quick-Stop module was designed for a pendulum-based cutting device to retain the chip on the workpiece. This approach allows the characterisation of oriented grain deformation and quantification of texture evolutions from the workpiece to the chip. By retaining deformed grains near the primary shear zone, it was found that the elongated grains in LPBF-fabricated Alloy 718 significantly influenced the material pile-up behaviour along the shear direction when compared with the equiaxed grains in the wrought sample, leading to an increase in shear angle and decrease in chip ratio. This is because the transition of shear deformation from the cutting edge to free surface is hindered by long grain boundaries that are perpendicular to the cutting direction. Since the shear bands are hard to cross long grain boundaries, the deformation is governed by grain boundary bending in the primary shear zone. In addition, it is revealed that the original textures in the wrought and LPBF-fabricated Alloy 718 tend to evolve into A-type and C-type shear textures respectively during chip formation. This indicates that the slip system family {111}< 112 > is easier to be activated in wrought 718 but < 110 > -directional slip is dominated in LPBF-fabricated 718.
{"title":"Influence of grain morphology on the chip formation mechanisms of wrought and laser powder bed fusion (LPBF) fabricated alloy 718","authors":"Lingshan Li , Shusong Zan , Zhirong Liao , Hao Chen , Dragos Axinte","doi":"10.1016/j.jmatprotec.2025.118740","DOIUrl":"10.1016/j.jmatprotec.2025.118740","url":null,"abstract":"<div><div>Understanding the role of grain morphology in the chip formation mechanism during orthogonal cutting is crucial to achieve reliable surface integrity. This is especially important when machining additively manufactured alloys due to the inherent presence of crystallographic textures from their unique grain growth patterns. In this work, wrought and laser powder bed fusion (LPBF) fabricated Alloy 718, representing equiaxed and elongated grains respectively, were employed as the case studies to investigate the influence of grain morphology on the chip formation. A new customised Quick-Stop module was designed for a pendulum-based cutting device to retain the chip on the workpiece. This approach allows the characterisation of oriented grain deformation and quantification of texture evolutions from the workpiece to the chip. By retaining deformed grains near the primary shear zone, it was found that the elongated grains in LPBF-fabricated Alloy 718 significantly influenced the material pile-up behaviour along the shear direction when compared with the equiaxed grains in the wrought sample, leading to an increase in shear angle and decrease in chip ratio. This is because the transition of shear deformation from the cutting edge to free surface is hindered by long grain boundaries that are perpendicular to the cutting direction. Since the shear bands are hard to cross long grain boundaries, the deformation is governed by grain boundary bending in the primary shear zone. In addition, it is revealed that the original textures in the wrought and LPBF-fabricated Alloy 718 tend to evolve into A-type and C-type shear textures respectively during chip formation. This indicates that the slip system family {111}< 112 > is easier to be activated in wrought 718 but < 110 > -directional slip is dominated in LPBF-fabricated 718.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"337 ","pages":"Article 118740"},"PeriodicalIF":6.7,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}