Pub Date : 2025-03-30DOI: 10.1016/j.matchar.2025.114993
Danielle Cristina Camilo Magalhães , Luciana Montanari , Sergio Alberto Elizalde Huitron , Jose Maria Cabrera Marrero , José Benaque Rubert , Sergio Henrique Evangelhista , Andrea Madeira Kliauga
This study explores the formability and fracture behavior of Al-based heterostructured materials (HM) fabricated using Accumulative Roll-Bonding (ARB) and assessed through Single Point Incremental Forming (SPIF). The HM sheets, consisting of alternating AA1050 and AA7050 layers, were processed at preheating temperatures of 450 °C and 500 °C. Detailed characterization using SEM, EBSD, and TEM revealed variations in grain size, crystallographic texture, and precipitate distributions between processing temperatures, influencing the strength, hardness and ductility of HM sheets. Tensile tests showed that sheets processed at 500 °C exhibited higher elongation and improved ductility compared to those processed at 450 °C, attributed to changes in size and distribution of precipitates. Forming Limit Curves (FLC) and SPIF experiments demonstrated superior formability at 500 °C, with the HM sheets achieving higher critical wall angles and fracture strains compared to AA7050 layers alone. The results highlighted the influence of ARB to induce microstructural features, including residual stresses and shear strain localization, on the forming behavior of HM sheets. The study underscores the potential of optimizing processing conditions and material compositions to enhance the mechanical performance and manufacturability of HM aluminum sheets.
{"title":"Investigation of single point incremental forming parameters and forming limit curves prediction for heterostructured aluminum sheets","authors":"Danielle Cristina Camilo Magalhães , Luciana Montanari , Sergio Alberto Elizalde Huitron , Jose Maria Cabrera Marrero , José Benaque Rubert , Sergio Henrique Evangelhista , Andrea Madeira Kliauga","doi":"10.1016/j.matchar.2025.114993","DOIUrl":"10.1016/j.matchar.2025.114993","url":null,"abstract":"<div><div>This study explores the formability and fracture behavior of Al-based heterostructured materials (HM) fabricated using Accumulative Roll-Bonding (ARB) and assessed through Single Point Incremental Forming (SPIF). The HM sheets, consisting of alternating AA1050 and AA7050 layers, were processed at preheating temperatures of 450 °C and 500 °C. Detailed characterization using SEM, EBSD, and TEM revealed variations in grain size, crystallographic texture, and precipitate distributions between processing temperatures, influencing the strength, hardness and ductility of HM sheets. Tensile tests showed that sheets processed at 500 °C exhibited higher elongation and improved ductility compared to those processed at 450 °C, attributed to changes in size and distribution of precipitates. Forming Limit Curves (FLC) and SPIF experiments demonstrated superior formability at 500 °C, with the HM sheets achieving higher critical wall angles and fracture strains compared to AA7050 layers alone. The results highlighted the influence of ARB to induce microstructural features, including residual stresses and shear strain localization, on the forming behavior of HM sheets. The study underscores the potential of optimizing processing conditions and material compositions to enhance the mechanical performance and manufacturability of HM aluminum sheets.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114993"},"PeriodicalIF":4.8,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746635","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 : 2025-03-28DOI: 10.1016/j.matchar.2025.114990
Yan Zhu , Yusen Li , Zhongwei Yan , Changhui Song , Jindong Tian , Shaohua Yan
Optimization of processing parameters is of great importance in additive manufacturing (AM) of metal alloys. Conventional trial-and-error approach is time- and cost-consumable, and the optimized parameters are sometimes sub-optimal, leading to the strength and ductility is not desirable. In this work, we employed Gaussian Process Regression machine learning (ML) to quickly find the optimized parameters for AM of CrCoNi MEA with relative density higher than 99 %. Using the optimized parameters, the additively manufactured CrCoNi MEA exhibited a tensile strength of 743 MPa and ductility of 59.5 %. The combination of the strength and ductility is 44.21GPa%, exceeding that of other CrCoNi MEA fabricated by AM without ML assistance. Such exceptional strength-ductility synergy was attributed to the original microstructures featuring fine grains, high dislocation density, and the deformed microstructural defects of twins, nanoscale network of stacking faults, dislocations, and the interactions between these defects. The method in this work sheds new sights into optimization of AM processing parameters and producing metal alloys with great strength-ductility synergy.
{"title":"Achieving exceptional strength-ductility synergy in a 3D-printed CrCoNi medium-entropy alloy with machine-learning assistance","authors":"Yan Zhu , Yusen Li , Zhongwei Yan , Changhui Song , Jindong Tian , Shaohua Yan","doi":"10.1016/j.matchar.2025.114990","DOIUrl":"10.1016/j.matchar.2025.114990","url":null,"abstract":"<div><div>Optimization of processing parameters is of great importance in additive manufacturing (AM) of metal alloys. Conventional trial-and-error approach is time- and cost-consumable, and the optimized parameters are sometimes sub-optimal, leading to the strength and ductility is not desirable. In this work, we employed Gaussian Process Regression machine learning (ML) to quickly find the optimized parameters for AM of CrCoNi MEA with relative density higher than 99 %. Using the optimized parameters, the additively manufactured CrCoNi MEA exhibited a tensile strength of 743 MPa and ductility of 59.5 %. The combination of the strength and ductility is 44.21GPa%, exceeding that of other CrCoNi MEA fabricated by AM without ML assistance. Such exceptional strength-ductility synergy was attributed to the original microstructures featuring fine grains, high dislocation density, and the deformed microstructural defects of twins, nanoscale network of stacking faults, dislocations, and the interactions between these defects. The method in this work sheds new sights into optimization of AM processing parameters and producing metal alloys with great strength-ductility synergy.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114990"},"PeriodicalIF":4.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746637","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 : 2025-03-26DOI: 10.1016/j.matchar.2025.114963
Owais Ahmad, Albert Linda, Saumya Ranjan Jha, Somanth Bhowmick
Microstructure imaging is crucial in materials science, but experimental images often introduce noise that obscures critical structural details. This study presents a novel deep learning approach for robust microstructure image denoising, combining phase-field simulations, Fourier transform techniques, and an attention-based neural network. The innovative framework addresses dataset limitations by synthetically generating training data by combining computational phase-field microstructures with experimental optical micrographs. The neural network architecture features an attention mechanism that dynamically focuses on important microstructural features while systematically eliminating noise types like scratches and surface imperfections. Testing on a FeMnNi alloy system demonstrated the model's exceptional performance across multiple magnifications. By successfully removing diverse noise patterns while maintaining grain boundary integrity, the research provides a generalizable deep-learning framework for microstructure image enhancement with broad applicability in materials science.
{"title":"A robust method of denoising experimental micrographs using deep learning","authors":"Owais Ahmad, Albert Linda, Saumya Ranjan Jha, Somanth Bhowmick","doi":"10.1016/j.matchar.2025.114963","DOIUrl":"10.1016/j.matchar.2025.114963","url":null,"abstract":"<div><div>Microstructure imaging is crucial in materials science, but experimental images often introduce noise that obscures critical structural details. This study presents a novel deep learning approach for robust microstructure image denoising, combining phase-field simulations, Fourier transform techniques, and an attention-based neural network. The innovative framework addresses dataset limitations by synthetically generating training data by combining computational phase-field microstructures with experimental optical micrographs. The neural network architecture features an attention mechanism that dynamically focuses on important microstructural features while systematically eliminating noise types like scratches and surface imperfections. Testing on a FeMnNi alloy system demonstrated the model's exceptional performance across multiple magnifications. By successfully removing diverse noise patterns while maintaining grain boundary integrity, the research provides a generalizable deep-learning framework for microstructure image enhancement with broad applicability in materials science.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114963"},"PeriodicalIF":4.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746632","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 : 2025-03-26DOI: 10.1016/j.matchar.2025.114983
Zhiqiang Xu , Wei Liu , Shufeng Yang , Hui Zhang , Jun Yan , Jingshe Li
Strength-ductility trade-off is a common issue in oxide dispersion strengthened (ODS) steels. Here, by designing oxide nanoparticles, a dual-heterostructure ODS-FeCrAl alloy has been developed to realize the combination of high strength and high ductility. The first level is heterogeneous oxide nanoparticles with different strengthening mechanisms, and the second level is heterogeneous zones with different grain sizes. The designed 0.5Y2O3 alloy achieves a perfect combination of ductility and strength at both room and high temperatures (650 °C) compared to a typical low Y2O3 ODS alloy (0.25Y2O3): nearly 20 % higher ductility at room temperature without any reduction in strength, and nearly 20 % higher ductility at high temperature with nearly 70 % higher strength. The optimal bimodal degree of the 0.5Y2O3 alloy and the coexistence of penetrable and impenetrable oxide nanoparticles play a dominant role in the strengthening-toughening effect. As the Y2O3 content increases, the fine Y2Zr2O7 and Y2Ti2O7 particles in ODS-FeCrAl alloys gradually transform into coarse, impenetrable YAl composite oxide particles. The beneficial effect of the bimodal structure on ductility is suppressed when the Y2O3 content exceeds 0.5 wt%, which is attributed to the premature failure of the ODS-FeCrAl alloy due to debonding of the unusually coarse YAl composite oxide nanoparticles during the deformation process. The effect of oxide nanoparticle properties on the thermal stability of ODS-FeCrAl alloys was also evaluated, and it was shown that the presence of a small fraction (∼26 %) of YAl composite oxide particles does not reduce the thermal stability of ODS-FeCrAl alloys.
{"title":"Dual heterostructure construction via tailored nanoprecipitates for strength-ductility trade-off in ODS steels","authors":"Zhiqiang Xu , Wei Liu , Shufeng Yang , Hui Zhang , Jun Yan , Jingshe Li","doi":"10.1016/j.matchar.2025.114983","DOIUrl":"10.1016/j.matchar.2025.114983","url":null,"abstract":"<div><div>Strength-ductility trade-off is a common issue in oxide dispersion strengthened (ODS) steels. Here, by designing oxide nanoparticles, a dual-heterostructure ODS-FeCrAl alloy has been developed to realize the combination of high strength and high ductility. The first level is heterogeneous oxide nanoparticles with different strengthening mechanisms, and the second level is heterogeneous zones with different grain sizes. The designed 0.5Y<sub>2</sub>O<sub>3</sub> alloy achieves a perfect combination of ductility and strength at both room and high temperatures (650 °C) compared to a typical low Y<sub>2</sub>O<sub>3</sub> ODS alloy (0.25Y<sub>2</sub>O<sub>3</sub>): nearly 20 % higher ductility at room temperature without any reduction in strength, and nearly 20 % higher ductility at high temperature with nearly 70 % higher strength. The optimal bimodal degree of the 0.5Y<sub>2</sub>O<sub>3</sub> alloy and the coexistence of penetrable and impenetrable oxide nanoparticles play a dominant role in the strengthening-toughening effect. As the Y<sub>2</sub>O<sub>3</sub> content increases, the fine Y<sub>2</sub>Zr<sub>2</sub>O<sub>7</sub> and Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> particles in ODS-FeCrAl alloys gradually transform into coarse, impenetrable Y<img>Al composite oxide particles. The beneficial effect of the bimodal structure on ductility is suppressed when the Y<sub>2</sub>O<sub>3</sub> content exceeds 0.5 wt%, which is attributed to the premature failure of the ODS-FeCrAl alloy due to debonding of the unusually coarse Y<img>Al composite oxide nanoparticles during the deformation process. The effect of oxide nanoparticle properties on the thermal stability of ODS-FeCrAl alloys was also evaluated, and it was shown that the presence of a small fraction (∼26 %) of Y<img>Al composite oxide particles does not reduce the thermal stability of ODS-FeCrAl alloys.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114983"},"PeriodicalIF":4.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746636","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 : 2025-03-25DOI: 10.1016/j.matchar.2025.114975
Chao Wei , Zhuang Zhao , Chao Wang , Qingfeng Yin , Xianfeng Shen , Jialin Yang , Guowei Wang , Yu Qin , Jingang Tang , Guomin Le , Yang Yang
High-strength bonded interfaces of additive manufacturing (AM) multi-material structures are usually obtained through extensive trial-and-error experiments, leading to increased manufacturing costs. In this study, a three-way optimization method is proposed based on thermodynamic calculations, which combines joining methods, deposition strategies, and post-heat treatment to achieve robust metallurgical bonding interfaces in the integrated laser additive manufacturing of extremely property-mismatched materials. The integrated forming of ultra-high strength steel (UHSS) and Ti6Al4V (TC4) was achieved with Ni-Cr-V interlayers via laser-directed energy deposition (LDED). The introduction of Ni-Cr-V interlayers emerged as a pivotal solution for addressing material compatibility between UHSS and TC4. By optimizing deposition strategies, high-quality UHSS-Ni, NiCr, CrV, and V-TC4 bonded interfaces were obtained without cracks or intermetallics. Furthermore, a customized post-heat treatment significantly enhanced the performance of LDED UHSS-Ni-Cr-V-TC4 sample (UTS: 120.9 MPa → 298.3 MPa), surpassing the UTS of the weakest material, Cr. The 3D-DIC results revealed distinct locations where plastic deformation (V region) and ultimate fracture (Cr region) occurred in the heat-treated sample, presenting a novel phenomenon that sharply contrasts with the behaviors displayed by homogeneous materials such as UHSS and TC4. This disparity primarily arises from the properties of materials (elastic modulus/strength). Finally, strategic approaches for fabricating high-quality AM multi-material structures were discussed. These findings enrich and advance the innovative theory of “material-structure-performance/function integrated laser additive manufacturing”, which holds important reference and guiding significance for the subsequent high-quality forming of other AM multi-material structures.
{"title":"Optimization for achieving robust metallurgical bonding interfaces in the integrated laser additive manufacturing of extremely property-mismatched materials","authors":"Chao Wei , Zhuang Zhao , Chao Wang , Qingfeng Yin , Xianfeng Shen , Jialin Yang , Guowei Wang , Yu Qin , Jingang Tang , Guomin Le , Yang Yang","doi":"10.1016/j.matchar.2025.114975","DOIUrl":"10.1016/j.matchar.2025.114975","url":null,"abstract":"<div><div>High-strength bonded interfaces of additive manufacturing (AM) multi-material structures are usually obtained through extensive trial-and-error experiments, leading to increased manufacturing costs. In this study, a three-way optimization method is proposed based on thermodynamic calculations, which combines joining methods, deposition strategies, and post-heat treatment to achieve robust metallurgical bonding interfaces in the integrated laser additive manufacturing of extremely property-mismatched materials. The integrated forming of ultra-high strength steel (UHSS) and Ti6Al4V (TC4) was achieved with Ni-Cr-V interlayers via laser-directed energy deposition (LDED). The introduction of Ni-Cr-V interlayers emerged as a pivotal solution for addressing material compatibility between UHSS and TC4. By optimizing deposition strategies, high-quality UHSS-Ni, Ni<img>Cr, Cr<img>V, and V-TC4 bonded interfaces were obtained without cracks or intermetallics. Furthermore, a customized post-heat treatment significantly enhanced the performance of LDED UHSS-Ni-Cr-V-TC4 sample (UTS: 120.9 MPa → 298.3 MPa), surpassing the UTS of the weakest material, Cr. The 3D-DIC results revealed distinct locations where plastic deformation (V region) and ultimate fracture (Cr region) occurred in the heat-treated sample, presenting a novel phenomenon that sharply contrasts with the behaviors displayed by homogeneous materials such as UHSS and TC4. This disparity primarily arises from the properties of materials (elastic modulus/strength). Finally, strategic approaches for fabricating high-quality AM multi-material structures were discussed. These findings enrich and advance the innovative theory of “material-structure-performance/function integrated laser additive manufacturing”, which holds important reference and guiding significance for the subsequent high-quality forming of other AM multi-material structures.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114975"},"PeriodicalIF":4.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715621","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 : 2025-03-25DOI: 10.1016/j.matchar.2025.114962
Jaderson Rodrigo da Silva Leal , Felipe Escher Saldanha , Guilherme Lisboa de Gouveia , José Eduardo Spinelli
One approach to addressing the growing demand for Al alloys in an environmentally sustainable manner is through recycling. However, the primary challenge involves mitigating the loss of mechanical properties and expanding the application range of scrap-containing alloys, primarily due to the formation of deleterious Fe-rich intermetallic phases. To tackle this issue, various methodologies have been explored, ranging from the less efficient dilution of scrap in primary Al to the use of elements such as Ni that modify these harmful phases, combined with control of solidification thermal parameters. Despite the potential of this approach, there is a notable gap in the literature regarding the formation kinetics of Fe-rich intermetallics under varying thermal conditions and the addition of Ni in Fe-rich Al alloys. This study investigates the Al-2Fe-1Ni alloy solidified at cooling rates of 0.5 K/s and 10.5 K/s using optical microscopy, SEM, XRD, EBSD, XCT, and tensile tests. The findings demonstrate the effectiveness of Ni in suppressing the formation of the primary Al13Fe4 intermetallic phase and promoting microstructures predominantly composed of eutectic cells containing Al + Al9FeNi. The Al9FeNi fibers within the eutectic cells exhibited morphological variations, with the central segments being more refined and orderly compared to the coarser and less aligned peripheric segments. Furthermore, the microstructural refinement induced by increasing the cooling rate during solidification (from approximately 1 K/s to 8 K/s) resulted in enhanced yield strength (from 88 MPa to 125 MPa) and tensile strength (from 116 MPa to 138 MPa), while maintaining ductility, as evidenced by a consistent fracture strain of approximately 25 %.
{"title":"Assessing microstructure, morphology, and mechanical properties of Al-2Fe-1Ni alloy through correlational characterization analysis","authors":"Jaderson Rodrigo da Silva Leal , Felipe Escher Saldanha , Guilherme Lisboa de Gouveia , José Eduardo Spinelli","doi":"10.1016/j.matchar.2025.114962","DOIUrl":"10.1016/j.matchar.2025.114962","url":null,"abstract":"<div><div>One approach to addressing the growing demand for Al alloys in an environmentally sustainable manner is through recycling. However, the primary challenge involves mitigating the loss of mechanical properties and expanding the application range of scrap-containing alloys, primarily due to the formation of deleterious Fe-rich intermetallic phases. To tackle this issue, various methodologies have been explored, ranging from the less efficient dilution of scrap in primary Al to the use of elements such as Ni that modify these harmful phases, combined with control of solidification thermal parameters. Despite the potential of this approach, there is a notable gap in the literature regarding the formation kinetics of Fe-rich intermetallics under varying thermal conditions and the addition of Ni in Fe-rich Al alloys. This study investigates the Al-2Fe-1Ni alloy solidified at cooling rates of 0.5 K/s and 10.5 K/s using optical microscopy, SEM, XRD, EBSD, XCT, and tensile tests. The findings demonstrate the effectiveness of Ni in suppressing the formation of the primary Al<sub>13</sub>Fe<sub>4</sub> intermetallic phase and promoting microstructures predominantly composed of eutectic cells containing Al + Al<sub>9</sub>FeNi. The Al<sub>9</sub>FeNi fibers within the eutectic cells exhibited morphological variations, with the central segments being more refined and orderly compared to the coarser and less aligned peripheric segments. Furthermore, the microstructural refinement induced by increasing the cooling rate during solidification (from approximately 1 K/s to 8 K/s) resulted in enhanced yield strength (from 88 MPa to 125 MPa) and tensile strength (from 116 MPa to 138 MPa), while maintaining ductility, as evidenced by a consistent fracture strain of approximately 25 %.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114962"},"PeriodicalIF":4.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734866","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 : 2025-03-25DOI: 10.1016/j.matchar.2025.114978
Yamin Li , Shutong Fan , Wentao Liu , Qian Chen , Hongjun Liu
Short-range order (SRO) structures are commonly found in various solid solution alloys such as NiCr, FeAl, medium/high entropy alloys, etc., which significantly affect the mechanical and functional properties of alloys. The K-state in many alloys is a typical inhomogeneous solid solution with SRO. However, the local atomic structure of the K-state is still unclear and the quantitative characterization of the SRO remains a formidable challenge. In this study, the microstructure of the K-state in the NiCrAlFe alloy was characterized by spherical aberration-corrected transmission electron microscopy, and based on crystallography and elastic distortion theory, three-dimensional reconstruction of the microscopic crystal structure was performed. From the results, the K-state crystal structure model of NiCr alloys is defined as Ni19Cr13, and the occupation of Ni and Cr atoms in short-range ordered solid solutions are clarified. The essence of the K-state is L12 SRO arranged along the 〈110〉 direction of the face-centered cubic (FCC) matrix. The L12 SRO domains with sizes of 1–5 nm are semi-coherent with a FCC matrix through a large number of edge dislocations, and the crystallographic orientation relationship between the FCC matrix and L12 SRO domains is , (BCT = body-centered tetragonal). The “local state” and “defect state” caused by the SRO of the K-state are the fundamental reasons for the change of the physical properties of the NiCrAlFe alloy. The proposed strategy can be generally used to investigate short-range ordering phenomena in different materials with the K-state and medium/high entropy alloys.
{"title":"L12 short-range order microstructure and ordered solid solution model of K-state in NiCrAlFe alloy","authors":"Yamin Li , Shutong Fan , Wentao Liu , Qian Chen , Hongjun Liu","doi":"10.1016/j.matchar.2025.114978","DOIUrl":"10.1016/j.matchar.2025.114978","url":null,"abstract":"<div><div>Short-range order (SRO) structures are commonly found in various solid solution alloys such as Ni<img>Cr, Fe<img>Al, medium/high entropy alloys, etc., which significantly affect the mechanical and functional properties of alloys. The K-state in many alloys is a typical inhomogeneous solid solution with SRO. However, the local atomic structure of the K-state is still unclear and the quantitative characterization of the SRO remains a formidable challenge. In this study, the microstructure of the K-state in the NiCrAlFe alloy was characterized by spherical aberration-corrected transmission electron microscopy, and based on crystallography and elastic distortion theory, three-dimensional reconstruction of the microscopic crystal structure was performed. From the results, the K-state crystal structure model of Ni<img>Cr alloys is defined as Ni<sub>19</sub>Cr<sub>13</sub>, and the occupation of Ni and Cr atoms in short-range ordered solid solutions are clarified. The essence of the K-state is L1<sub>2</sub> SRO arranged along the 〈110〉 direction of the face-centered cubic (FCC) matrix. The L1<sub>2</sub> SRO domains with sizes of 1–5 nm are semi-coherent with a FCC matrix through a large number of edge dislocations, and the crystallographic orientation relationship between the FCC matrix and L1<sub>2</sub> SRO domains is <span><math><msub><mfenced><mn>100</mn></mfenced><mi>BCT</mi></msub><mo>/</mo><mo>/</mo><msub><mfenced><mn>110</mn></mfenced><mi>FCC</mi></msub></math></span>, <span><math><msub><mfenced><mn>100</mn></mfenced><mi>BCT</mi></msub><mo>/</mo><mo>/</mo><msub><mfenced><mn>100</mn></mfenced><mi>FCC</mi></msub></math></span> (BCT = body-centered tetragonal). The “local state” and “defect state” caused by the SRO of the K-state are the fundamental reasons for the change of the physical properties of the NiCrAlFe alloy. The proposed strategy can be generally used to investigate short-range ordering phenomena in different materials with the K-state and medium/high entropy alloys.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114978"},"PeriodicalIF":4.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715622","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 : 2025-03-25DOI: 10.1016/j.matchar.2025.114979
Yanzhi Peng , Jian Wang , Zunyan Xu , Li Fu , Liyuan Liu , Qiong Lu , Jingmei Tao , Rui Bao , Jianhong Yi , Caiju Li
The mechanical properties of Al-11Si-3Cu-2Ni-1 Mg alloy (M142 alloy) are significantly affected by grain size, Si phase and intermetallic phase size and distribution. Therefore, the regulation of microstructure is very important to improve the mechanical properties of the alloy. In this work, high performance TiB2/M142 composites were prepared by powder metallurgy and hot extrusion. The results show that TiB2 particles can effectively refine the grain and the second phase, and induce more intragranular intermetallic phases. With the increase of TiB2 content, the strength increased continuously, but the ductility increased first and then decreased. The improvement of the strength of the composites are mainly attributed to thermal mismatch strengthening. The first increase in ductility is mainly due to the capture and pin of the dislocation by intragranular intermetallic phases, which makes the grains have stronger dislocation accumulation and storage capacity. The subsequent reduction in ductility is mainly attributed to the local stress concentration in the TiB2 agglomeration region, which eventually leads to the rapid failure of the composites.
{"title":"Effect of TiB2 particles on the microstructure and mechanical properties of Al-Si-Cu-Mg-Ni alloy fabricated by powder metallurgy","authors":"Yanzhi Peng , Jian Wang , Zunyan Xu , Li Fu , Liyuan Liu , Qiong Lu , Jingmei Tao , Rui Bao , Jianhong Yi , Caiju Li","doi":"10.1016/j.matchar.2025.114979","DOIUrl":"10.1016/j.matchar.2025.114979","url":null,"abstract":"<div><div>The mechanical properties of Al-11Si-3Cu-2Ni-1 Mg alloy (M142 alloy) are significantly affected by grain size, Si phase and intermetallic phase size and distribution. Therefore, the regulation of microstructure is very important to improve the mechanical properties of the alloy. In this work, high performance TiB<sub>2</sub>/M142 composites were prepared by powder metallurgy and hot extrusion. The results show that TiB<sub>2</sub> particles can effectively refine the grain and the second phase, and induce more intragranular intermetallic phases. With the increase of TiB<sub>2</sub> content, the strength increased continuously, but the ductility increased first and then decreased. The improvement of the strength of the composites are mainly attributed to thermal mismatch strengthening. The first increase in ductility is mainly due to the capture and pin of the dislocation by intragranular intermetallic phases, which makes the grains have stronger dislocation accumulation and storage capacity. The subsequent reduction in ductility is mainly attributed to the local stress concentration in the TiB<sub>2</sub> agglomeration region, which eventually leads to the rapid failure of the composites.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114979"},"PeriodicalIF":4.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715619","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 : 2025-03-25DOI: 10.1016/j.matchar.2025.114955
Wei Jian Chen , Zi Yao Wei , Shun Hu Zhang , Ming Kun Ge , Xin Dai , Shun Wu
This study elucidates the coupled enhancement of yield strength and hydrogen embrittlement (HE) resistance in a 2200 MPa press-hardened steel (PHS) through tempering treatments. The results indicate that as the tempering temperature rises, the dislocation density decreases, and the type of precipitated particles changes from needle-like ε-carbides to rod-like η-carbides. Quantitative strengthening mechanism analysis demonstrates that although dislocation strengthening diminishes by 176 MPa after 300 °C tempering, the overall yield strength increases by 186 MPa (reaching 1624 MPa) due to enhanced precipitation strengthening through the interaction between the ε/η-carbides and dislocations. Furthermore, the HE sensitivity of ultra-high strength PHS is governed by the diffusible hydrogen trapped in the dislocations and grain boundaries. Notably, the precipitated particles (semi-coherent (V, Nb)C and ε/η-carbides) effectively suppress both hydrogen-enhanced decohesion (HEDE) and hydrogen-enhanced localized plasticity (HELP) mechanisms by hindering the movement of dislocation‑hydrogen atmospheres. This synergistic effect achieves remarkable HE resistance (fracture strength loss of 1.3 % and displacement loss of 13.2 %) while maintaining ultrahigh strength.
{"title":"Microstructure evolution and hydrogen embrittlement mechanism of a 2200 MPa press-hardened steel with tempering treatment","authors":"Wei Jian Chen , Zi Yao Wei , Shun Hu Zhang , Ming Kun Ge , Xin Dai , Shun Wu","doi":"10.1016/j.matchar.2025.114955","DOIUrl":"10.1016/j.matchar.2025.114955","url":null,"abstract":"<div><div>This study elucidates the coupled enhancement of yield strength and hydrogen embrittlement (HE) resistance in a 2200 MPa press-hardened steel (PHS) through tempering treatments. The results indicate that as the tempering temperature rises, the dislocation density decreases, and the type of precipitated particles changes from needle-like ε-carbides to rod-like η-carbides. Quantitative strengthening mechanism analysis demonstrates that although dislocation strengthening diminishes by 176 MPa after 300 °C tempering, the overall yield strength increases by 186 MPa (reaching 1624 MPa) due to enhanced precipitation strengthening through the interaction between the ε/η-carbides and dislocations. Furthermore, the HE sensitivity of ultra-high strength PHS is governed by the diffusible hydrogen trapped in the dislocations and grain boundaries. Notably, the precipitated particles (semi-coherent (V, Nb)C and ε/η-carbides) effectively suppress both hydrogen-enhanced decohesion (HEDE) and hydrogen-enhanced localized plasticity (HELP) mechanisms by hindering the movement of dislocation‑hydrogen atmospheres. This synergistic effect achieves remarkable HE resistance (fracture strength loss of 1.3 % and displacement loss of 13.2 %) while maintaining ultrahigh strength.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114955"},"PeriodicalIF":4.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715623","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}
This study conducted a detailed analysis of the microstructure evolution and mechanical properties of a series of CuxCoCrNiAl high-entropy alloys (HEAs) to assess the influence of Cu content on HEAs. The findings indicated that with increasing Cu content, the alloy's phase structure changed from FCC1 + FCC2 (AlCu) + BCC to FCC phase. As the Cu content rose from 20 % to 80 %, the hardness of the alloy decreased progressively from 515 HV to 135 HV, and the ultimate tensile strength reduced from 1335 MPa to 524 MPa. The fracture mechanism shifted from a mixed brittle-ductile fracture to a ductile fracture. Consequently, the Cu4CoCrNiAl HEA (CA50) demonstrated superior overall mechanical properties, with hardness, yield strength, ultimate tensile strength, and elongation measured at 321 HV, 556 MPa, 846 MPa, and 16.4 %, respectively. This research is significant for the advancement of engineering and structural materials with outstanding mechanical properties.
{"title":"The role of copper in transforming CuxCoCrNiAl high-entropy alloys for enhanced strength and ductility","authors":"Fa-Chang Zhao , Guo-Ning Ji , Xing-Ming Zhao, Rong-Da Zhao, Fu-Fa Wu","doi":"10.1016/j.matchar.2025.114973","DOIUrl":"10.1016/j.matchar.2025.114973","url":null,"abstract":"<div><div>This study conducted a detailed analysis of the microstructure evolution and mechanical properties of a series of Cu<sub><em>x</em></sub>CoCrNiAl high-entropy alloys (HEAs) to assess the influence of Cu content on HEAs. The findings indicated that with increasing Cu content, the alloy's phase structure changed from FCC1 + FCC2 (AlCu) + BCC to FCC phase. As the Cu content rose from 20 % to 80 %, the hardness of the alloy decreased progressively from 515 HV to 135 HV, and the ultimate tensile strength reduced from 1335 MPa to 524 MPa. The fracture mechanism shifted from a mixed brittle-ductile fracture to a ductile fracture. Consequently, the Cu<sub>4</sub>CoCrNiAl HEA (CA50) demonstrated superior overall mechanical properties, with hardness, yield strength, ultimate tensile strength, and elongation measured at 321 HV, 556 MPa, 846 MPa, and 16.4 %, respectively. This research is significant for the advancement of engineering and structural materials with outstanding mechanical properties.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114973"},"PeriodicalIF":4.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715755","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号