Pub Date : 2025-01-04DOI: 10.1016/j.jmrt.2025.01.009
Xiaohui Liu , Tianjian Yu , Shuaixing Wang , Shujing Liu , Chaojun Xu , Nan Du
Ultrasonic surface rolling process (USRP) has attracted significant attention in metal surface strengthening due to its ability to tailor microstructural features and enhance mechanical properties. However, its effects on aluminum alloys remain insufficiently understood. This study aims to produce 7075-T6 aluminum alloys with varying surface conditions by adjusting the static pressure during USRP. The influence of gradient hardness and residual stress on rotating-bending fatigue properties was investigated. The results reveal that USRP induces surface gradient layers characterized by work hardening, compressive residual stress, and a high density of dislocations. At a static pressure of 200 N, the surface hardness and residual compressive stress reach 167 HV and 560 MPa, respectively. Enhanced surface hardness inhibits fatigue crack initiation, while compressive residual stress and dislocation density delay crack propagation. Consequently, the fatigue life of the USRP-200 N sample reaches 7.9 × 106 cycles under 300 MPa, approximately 100 times longer than that of the untreated alloy.
{"title":"Influence of ultrasonic surface rolling process on the microstructure and rotating-bending fatigue properties of 7075-T6 aluminum alloys","authors":"Xiaohui Liu , Tianjian Yu , Shuaixing Wang , Shujing Liu , Chaojun Xu , Nan Du","doi":"10.1016/j.jmrt.2025.01.009","DOIUrl":"10.1016/j.jmrt.2025.01.009","url":null,"abstract":"<div><div>Ultrasonic surface rolling process (USRP) has attracted significant attention in metal surface strengthening due to its ability to tailor microstructural features and enhance mechanical properties. However, its effects on aluminum alloys remain insufficiently understood. This study aims to produce 7075-T6 aluminum alloys with varying surface conditions by adjusting the static pressure during USRP. The influence of gradient hardness and residual stress on rotating-bending fatigue properties was investigated. The results reveal that USRP induces surface gradient layers characterized by work hardening, compressive residual stress, and a high density of dislocations. At a static pressure of 200 N, the surface hardness and residual compressive stress reach 167 HV and 560 MPa, respectively. Enhanced surface hardness inhibits fatigue crack initiation, while compressive residual stress and dislocation density delay crack propagation. Consequently, the fatigue life of the USRP-200 N sample reaches 7.9 × 10<sup>6</sup> cycles under 300 MPa, approximately 100 times longer than that of the untreated alloy.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 185-192"},"PeriodicalIF":6.2,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104608","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}
Pub Date : 2025-01-04DOI: 10.1016/j.jmrt.2025.01.006
Xingyu Zhao , Xiaoxin Zhang , Junquan Zhou , Yingxue Chen , Feifei Zhang , Jun Zhang , Qingzhi Yan
Cu-bearing high strength low carbon (HSLC) steel possesses high strength due to the existence of finely dispersed Cu-rich phases within the matrix. However, such high precipitation strengthening results in the loss of toughness. To break this strength-toughness trade-off, we propose a new strategy of direct quenching followed by double tempering (DQ-TT). Over four times higher energy was found in the DQ-TT sample (74 J) at −84oC compared to the other samples with single tempering (DQ-T, 13 J) and reheated quenching (RQ-TT, 6 J) without the sacrifice of strength. This high toughness is proved to be derived from: the higher cleavage fracture stress () and the higher crack initiation and propagation energy. The former comes from the refined effective grain sizes (EGS, 5.66 μm) and the optimized element segregation, where Cu (low enrichment ratio of 2.75) and Mo (high enrichment ratio of 35.20). The reduced segregation of Cu and the enrichment of Mo at the lath boundaries can effectively enhance the interfacial bonding strength. The latter is related to the orientations of the materials. It is measured that the DQ-TT sample has higher <110>//RD (47.8%) and <001>//ND (20.5%) deformation textures, which correspond to the {001} cleavage plane parallel to the RD and {110} slip plane parallel to the ND. The weak {001}//RD and strong {110}//ND ensure crack initiation and propagation along weak interfaces while preventing significant cleavage fracture. Oscilloscope impact tests reveal that DQ-TT process possesses higher crack initiation and propagation energy, which are 20 J and 37 J, respectively.
{"title":"Direct quenching and double tempering obtain high strength and toughness of Cu-bearing HSLC martensitic steel","authors":"Xingyu Zhao , Xiaoxin Zhang , Junquan Zhou , Yingxue Chen , Feifei Zhang , Jun Zhang , Qingzhi Yan","doi":"10.1016/j.jmrt.2025.01.006","DOIUrl":"10.1016/j.jmrt.2025.01.006","url":null,"abstract":"<div><div>Cu-bearing high strength low carbon (HSLC) steel possesses high strength due to the existence of finely dispersed Cu-rich phases within the matrix. However, such high precipitation strengthening results in the loss of toughness. To break this strength-toughness trade-off, we propose a new strategy of direct quenching followed by double tempering (DQ-TT). Over four times higher energy was found in the DQ-TT sample (74 J) at −84<sup>o</sup>C compared to the other samples with single tempering (DQ-T, 13 J) and reheated quenching (RQ-TT, 6 J) without the sacrifice of strength. This high toughness is proved to be derived from: the higher cleavage fracture stress (<span><math><mrow><msub><mi>σ</mi><mi>F</mi></msub></mrow></math></span>) and the higher crack initiation and propagation energy. The former comes from the refined effective grain sizes (EGS, 5.66 μm) and the optimized element segregation, where Cu (low enrichment ratio of 2.75) and Mo (high enrichment ratio of 35.20). The reduced segregation of Cu and the enrichment of Mo at the lath boundaries can effectively enhance the interfacial bonding strength. The latter is related to the orientations of the materials. It is measured that the DQ-TT sample has higher <110>//RD (47.8%) and <001>//ND (20.5%) deformation textures, which correspond to the {001} cleavage plane parallel to the RD and {110} slip plane parallel to the ND. The weak {001}//RD and strong {110}//ND ensure crack initiation and propagation along weak interfaces while preventing significant cleavage fracture. Oscilloscope impact tests reveal that DQ-TT process possesses higher crack initiation and propagation energy, which are 20 J and 37 J, respectively.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 13-24"},"PeriodicalIF":6.2,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104282","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}
Pub Date : 2025-01-04DOI: 10.1016/j.jmrt.2025.01.010
Long Hou , Wenjun Liu , Mengen Shi , Benjun Wang , Quanhe Bao , Cong Liu , Hanchen Feng , Qizhong Shang , Weihuo Li , Zhineng Xie
Achieving the industrial production of high-performance nanocrystalline alloys is an active research topic in which oxidation is an inescapable and top-priority issue that needs to be addressed. In this study, we conducted a comprehensive investigation into the oxidation and crystallization behaviors of dual-phase FeNiBCu nanocrystalline alloys, as well as the mechanisms underlying the relationship between oxidation and magnetic properties. The chemical valence states and microstructures analysis, indicative of galvanic cell structures, demonstrated that the concentration and activity of Fe in nanocrystals were higher than those in the matrix, thus providing effective nucleation sites for Fe-oxides. Unique delamination morphology and inner structure distinctly regulated the magnetization-magnetic softness (Bs-Hc) tradeoff. Consequently, the alloy underwent simultaneous crystallization and oxidation, affording a high Bs of 1.70 T and a low Hc of 3.5 A/m. These results enhance our understanding of the effect of oxidation on magnetic properties and provide a theoretical reference for the industrial heat treatment of high-performance nanocrystalline alloys.
{"title":"Unveiling the correlation between oxidation and magnetic properties in dual-phase FeNiBCu nanocrystalline alloys","authors":"Long Hou , Wenjun Liu , Mengen Shi , Benjun Wang , Quanhe Bao , Cong Liu , Hanchen Feng , Qizhong Shang , Weihuo Li , Zhineng Xie","doi":"10.1016/j.jmrt.2025.01.010","DOIUrl":"10.1016/j.jmrt.2025.01.010","url":null,"abstract":"<div><div>Achieving the industrial production of high-performance nanocrystalline alloys is an active research topic in which oxidation is an inescapable and top-priority issue that needs to be addressed. In this study, we conducted a comprehensive investigation into the oxidation and crystallization behaviors of dual-phase FeNiBCu nanocrystalline alloys, as well as the mechanisms underlying the relationship between oxidation and magnetic properties. The chemical valence states and microstructures analysis, indicative of galvanic cell structures, demonstrated that the concentration and activity of Fe in nanocrystals were higher than those in the matrix, thus providing effective nucleation sites for Fe-oxides. Unique delamination morphology and inner structure distinctly regulated the magnetization-magnetic softness (<em>B</em><sub>s</sub>-<em>H</em><sub>c</sub>) tradeoff. Consequently, the alloy underwent simultaneous crystallization and oxidation, affording a high <em>B</em><sub>s</sub> of 1.70 T and a low <em>H</em><sub>c</sub> of 3.5 A/m. These results enhance our understanding of the effect of oxidation on magnetic properties and provide a theoretical reference for the industrial heat treatment of high-performance nanocrystalline alloys.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 110-118"},"PeriodicalIF":6.2,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104613","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}
Pub Date : 2025-01-02DOI: 10.1016/j.jmrt.2024.12.228
Simeng Jiang , Yaya Zhao , Weijie Fan , Weiyang Xie , Yanlin Wang , Xiaohua Chen , Zidong Wang
In this study, a novel preparation method for high-entropy alloys (HEAs) was developed. Al0.43CoCrFeNi2.1 HEA ingots were cast under complex shear flow, while a comparison group was cast without applying shear flow. Various characterization techniques were employed to analyze the microstructural differences between the two samples. Molecular dynamics (MD) simulations were used to investigate the nucleation characteristics, microstructure evolution, and dislocation evolution during solidification. Additionally, to investigate the deformation properties and mechanical behavior of the two samples, uniaxial tension was applied to the solidified samples using MD simulations. The results reveal that by introducing severe shear flow, the equiaxed grains of the Al0.43CoCrFeNi2.1 HEA alloy were refined, twins were formed, and the likelihood of dislocation ring formation and dislocation entanglement during solidification decreased. Compared to the traditional method, the sample prepared by complex shear flow casting (CSFC) exhibits yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) of 330.7 MPa, 661.7 MPa, and 54.8%, respectively, showing increases of 23.1%, 26.6%, and 7.5%, respectively. The strengthening and toughening mechanisms were discussed, suggesting that the refinement of equiaxed grains, the elimination of dislocation entanglement, the twinning-induced plasticity (TWIP) effect during deformation, and the transformation-induced plasticity (TRIP) effect induced by fivefold twins contribute to the improvement of mechanical properties. The novel CFSC method holds significant potential for applications in HEAs.
{"title":"Enhanced mechanical properties of Al0.43CoCrFeNi2.1 high entropy alloy fabricated through complex shear flow casting: Experiment and MD simulation","authors":"Simeng Jiang , Yaya Zhao , Weijie Fan , Weiyang Xie , Yanlin Wang , Xiaohua Chen , Zidong Wang","doi":"10.1016/j.jmrt.2024.12.228","DOIUrl":"10.1016/j.jmrt.2024.12.228","url":null,"abstract":"<div><div>In this study, a novel preparation method for high-entropy alloys (HEAs) was developed. Al<sub>0.43</sub>CoCrFeNi<sub>2.1</sub> HEA ingots were cast under complex shear flow, while a comparison group was cast without applying shear flow. Various characterization techniques were employed to analyze the microstructural differences between the two samples. Molecular dynamics (MD) simulations were used to investigate the nucleation characteristics, microstructure evolution, and dislocation evolution during solidification. Additionally, to investigate the deformation properties and mechanical behavior of the two samples, uniaxial tension was applied to the solidified samples using MD simulations. The results reveal that by introducing severe shear flow, the equiaxed grains of the Al<sub>0.43</sub>CoCrFeNi<sub>2.1</sub> HEA alloy were refined, twins were formed, and the likelihood of dislocation ring formation and dislocation entanglement during solidification decreased. Compared to the traditional method, the sample prepared by complex shear flow casting (CSFC) exhibits yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) of 330.7 MPa, 661.7 MPa, and 54.8%, respectively, showing increases of 23.1%, 26.6%, and 7.5%, respectively. The strengthening and toughening mechanisms were discussed, suggesting that the refinement of equiaxed grains, the elimination of dislocation entanglement, the twinning-induced plasticity (TWIP) effect during deformation, and the transformation-induced plasticity (TRIP) effect induced by fivefold twins contribute to the improvement of mechanical properties. The novel CFSC method holds significant potential for applications in HEAs.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 67-81"},"PeriodicalIF":6.2,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104614","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}
Pub Date : 2025-01-02DOI: 10.1016/j.jmrt.2025.01.003
Jeremias Ismael Nunes Fortini , Pedro Henrique Poubel Mendonça da Silveira , Sergio Neves Monteiro , Altair Sória Pereira , Eduardo Sousa Lima
Modern armed conflicts heavily rely on technology to ensure the safety of combatants in police operations, tactical warfare, or military engagements. The use of ceramic armor has become common to provide protection against high-caliber munitions, making it essential to optimize these materials for a combination of lightness and strength. In this context, this study justifies the use of silicon (Si) as a reinforcement in silicon carbide (SiC) to reduce the ceramics' density without compromising their mechanical properties and ballistic performance. The addition of Si allows a reduction in the density of sintered samples with 15 and 25 vol% Si, contributing to the material's lightness, a crucial factor for user mobility. The results show that despite the lower density, the hardness of SiC ceramics increased with higher Si additions, though there was a decrease in flexural strength and elastic modulus. Ballistic tests demonstrated that the produced ceramics effectively withstood the firing of 5.56 × 45 mm caliber ammunition, meeting the requirements of the new standard under development for ballistic materials, NIJ 0123.00. This research makes significant contributions to the development of advanced armor systems, enhancing combatant safety through lightweight, high-performance ballistic materials.
{"title":"Mechanical, microstructural properties and ballistic performance of SiC/Si ceramics against 5.56 x 45 mm projectile","authors":"Jeremias Ismael Nunes Fortini , Pedro Henrique Poubel Mendonça da Silveira , Sergio Neves Monteiro , Altair Sória Pereira , Eduardo Sousa Lima","doi":"10.1016/j.jmrt.2025.01.003","DOIUrl":"10.1016/j.jmrt.2025.01.003","url":null,"abstract":"<div><div>Modern armed conflicts heavily rely on technology to ensure the safety of combatants in police operations, tactical warfare, or military engagements. The use of ceramic armor has become common to provide protection against high-caliber munitions, making it essential to optimize these materials for a combination of lightness and strength. In this context, this study justifies the use of silicon (Si) as a reinforcement in silicon carbide (SiC) to reduce the ceramics' density without compromising their mechanical properties and ballistic performance. The addition of Si allows a reduction in the density of sintered samples with 15 and 25 vol% Si, contributing to the material's lightness, a crucial factor for user mobility. The results show that despite the lower density, the hardness of SiC ceramics increased with higher Si additions, though there was a decrease in flexural strength and elastic modulus. Ballistic tests demonstrated that the produced ceramics effectively withstood the firing of 5.56 × 45 mm caliber ammunition, meeting the requirements of the new standard under development for ballistic materials, NIJ 0123.00. This research makes significant contributions to the development of advanced armor systems, enhancing combatant safety through lightweight, high-performance ballistic materials.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 208-219"},"PeriodicalIF":6.2,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104335","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}
Pub Date : 2025-01-01DOI: 10.1016/j.jmrt.2024.12.063
Luana Souza Almeida , Paulo Rangel Rios
The advances in manufacturing technologies have enabled the production of Voronoi structures. The main advantage of these complex designs is their lightweight and enhanced mechanical properties, such as high buckling resistance. Some applications of Voronoi structures are in reducing the weight of automotive and aerospace parts and developing biomedical implants. Metaheuristics are being used to optimize these structures while improving their mechanical properties. Hence, in this study, a systematic review is conducted to identify the trends and gaps in the use of the Genetic Algorithm to optimize two and three-dimensional Voronoi structures. The results mapped seven application domains and suggest that future research should combine manufacturability and optimization constraints, such as additive manufacturing restrictions. In addition, alternative materials (e.g., ceramics and metals) could be used to create specimens for the mechanical tests, and other approaches to finite element simulation are required to speed up the optimization process. The quantitative analysis suggests that this is an emerging topic, with few researchers in local groups cooperating to develop the field.
{"title":"Insights on the use of genetic algorithm to tessellate voronoi structures in materials science","authors":"Luana Souza Almeida , Paulo Rangel Rios","doi":"10.1016/j.jmrt.2024.12.063","DOIUrl":"10.1016/j.jmrt.2024.12.063","url":null,"abstract":"<div><div>The advances in manufacturing technologies have enabled the production of Voronoi structures. The main advantage of these complex designs is their lightweight and enhanced mechanical properties, such as high buckling resistance. Some applications of Voronoi structures are in reducing the weight of automotive and aerospace parts and developing biomedical implants. Metaheuristics are being used to optimize these structures while improving their mechanical properties. Hence, in this study, a systematic review is conducted to identify the trends and gaps in the use of the Genetic Algorithm to optimize two and three-dimensional Voronoi structures. The results mapped seven application domains and suggest that future research should combine manufacturability and optimization constraints, such as additive manufacturing restrictions. In addition, alternative materials (e.g., ceramics and metals) could be used to create specimens for the mechanical tests, and other approaches to finite element simulation are required to speed up the optimization process. The quantitative analysis suggests that this is an emerging topic, with few researchers in local groups cooperating to develop the field.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"34 ","pages":"Pages 449-462"},"PeriodicalIF":6.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095442","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}
Pub Date : 2025-01-01DOI: 10.1016/j.jmrt.2024.12.036
Melika Jalali , Hamid Reza Jafarian , Ali Shanaghi , Ali Reza Eivani
This study investigates the influence of the Accumulative Roll-Bonding (ARB) process on the corrosion behavior of Fe-28.5Ni alloys. The research examines how the ARB as a severe plastic deformation technique alters the microstructure and corrosion resistance of this alloy. Specimens subjected to different ARB cycles were analyzed using electrochemical impedance spectroscopy, cyclic potentiodynamic polarization, and open-circuit potential measurements in 1 M HCl solution. Results indicate that increasing the number of ARB cycles initially decreases corrosion resistance due to higher dislocation densities. However, after four cycles, the formation of low-angle grain boundaries enhances corrosion resistance by creating a more uniform surface energy distribution and stable corrosion product layers. Optimal corrosion resistance was observed at six ARB cycles, beyond which high-angle grain boundaries began to diminish the protective effects. This study underscores the significance of optimizing ARB parameters to improve the performance of Fe–Ni alloys in corrosive environments.
{"title":"On the microstructure and corrosion behavior of Fe-28.5Ni steel subjected to severe plastic deformation","authors":"Melika Jalali , Hamid Reza Jafarian , Ali Shanaghi , Ali Reza Eivani","doi":"10.1016/j.jmrt.2024.12.036","DOIUrl":"10.1016/j.jmrt.2024.12.036","url":null,"abstract":"<div><div>This study investigates the influence of the Accumulative Roll-Bonding (ARB) process on the corrosion behavior of Fe-28.5Ni alloys. The research examines how the ARB as a severe plastic deformation technique alters the microstructure and corrosion resistance of this alloy. Specimens subjected to different ARB cycles were analyzed using electrochemical impedance spectroscopy, cyclic potentiodynamic polarization, and open-circuit potential measurements in 1 M HCl solution. Results indicate that increasing the number of ARB cycles initially decreases corrosion resistance due to higher dislocation densities. However, after four cycles, the formation of low-angle grain boundaries enhances corrosion resistance by creating a more uniform surface energy distribution and stable corrosion product layers. Optimal corrosion resistance was observed at six ARB cycles, beyond which high-angle grain boundaries began to diminish the protective effects. This study underscores the significance of optimizing ARB parameters to improve the performance of Fe–Ni alloys in corrosive environments.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"34 ","pages":"Pages 90-99"},"PeriodicalIF":6.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095701","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}
Pub Date : 2025-01-01DOI: 10.1016/j.jmrt.2024.12.046
Mingyang Liu , Tianyu Zhang , Chenchong Wang , Ye Liu , Junyang Qian , Hongshuang Di , Qing Yin , Chi Zhang
GCr15 steel, renowned as one of the most extensively utilized metallic materials in bearing applications, has been the subject of considerable research, particularly regarding its hot deformation behavior. However, the effect of macro- and micro-segregation on the hot deformation behavior of GCr15 steel remains underexplored. In this study, a comprehensive investigation was conducted to systematically assess the hot deformation behavior of continuously cast GCr15 steel under varying degrees of macro- and micro-segregation through hot compression testing. Flow curves were utilized to construct hot processing maps, enabling a detailed analysis of the effects of segregation on hot workability. The findings reveal that, at a deformation temperature of 800 °C and a strain rate of 10 s−1, the negatively segregated regions of GCr15 steel exhibit a greater propensity for instability during hot working than their positively segregated counterparts. This heightened instability, which accelerates with increasing true strain, can be attributed to stress concentrations arising from inhomogeneities inherent to the continuous casting process. Additionally, the negative macro-segregation zone demonstrated superior hot workability, attributed to its lower hardness. Based on these observations, the optimal hot processing conditions were identified as a deformation temperature of 1000 °C and a strain rate of 0.1 s−1.
{"title":"Effect of segregation on hot deformation behavior of GCr15 bearing steel in continuous casting","authors":"Mingyang Liu , Tianyu Zhang , Chenchong Wang , Ye Liu , Junyang Qian , Hongshuang Di , Qing Yin , Chi Zhang","doi":"10.1016/j.jmrt.2024.12.046","DOIUrl":"10.1016/j.jmrt.2024.12.046","url":null,"abstract":"<div><div>GCr15 steel, renowned as one of the most extensively utilized metallic materials in bearing applications, has been the subject of considerable research, particularly regarding its hot deformation behavior. However, the effect of macro- and micro-segregation on the hot deformation behavior of GCr15 steel remains underexplored. In this study, a comprehensive investigation was conducted to systematically assess the hot deformation behavior of continuously cast GCr15 steel under varying degrees of macro- and micro-segregation through hot compression testing. Flow curves were utilized to construct hot processing maps, enabling a detailed analysis of the effects of segregation on hot workability. The findings reveal that, at a deformation temperature of 800 °C and a strain rate of 10 s<sup>−1</sup>, the negatively segregated regions of GCr15 steel exhibit a greater propensity for instability during hot working than their positively segregated counterparts. This heightened instability, which accelerates with increasing true strain, can be attributed to stress concentrations arising from inhomogeneities inherent to the continuous casting process. Additionally, the negative macro-segregation zone demonstrated superior hot workability, attributed to its lower hardness. Based on these observations, the optimal hot processing conditions were identified as a deformation temperature of 1000 °C and a strain rate of 0.1 s<sup>−1</sup>.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"34 ","pages":"Pages 48-57"},"PeriodicalIF":6.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095703","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}
Pub Date : 2025-01-01DOI: 10.1016/j.jmrt.2024.11.275
Mike Ashby
Fred Kocks' professional life spanned a period of intense development in the understanding of the micromechanics of plastic flow. Continuum plasticity theory and the concepts of crystal plasticity with defined slip planes and directions were well established in 1959 when Fred graduated from the University of Göttingen. The concept of dislocations, discrete carriers of deformation, and their interactions, had initiated a wave of activity across Europe and the US, offering the potential for micro-mechanical models for plastic flow and its dependence on composition, temperature, time (strain-rate) and prior mechanical history. Fred became one of the principal players in the field, starting with his 1958 study of the deformation of polycrystals [1]. To understand his approach and his subsequent contributions it helps to have a picture of the intellectual climate of Göttingen and the excitement of generated by dislocation-plasticity at that time. This brief paper describes this context in which Fred's work should be viewed.
{"title":"Models for plastic flow: People, places, concepts and techniques","authors":"Mike Ashby","doi":"10.1016/j.jmrt.2024.11.275","DOIUrl":"10.1016/j.jmrt.2024.11.275","url":null,"abstract":"<div><div>Fred Kocks' professional life spanned a period of intense development in the understanding of the micromechanics of plastic flow. Continuum plasticity theory and the concepts of crystal plasticity with defined slip planes and directions were well established in 1959 when Fred graduated from the University of Göttingen. The concept of dislocations, discrete carriers of deformation, and their interactions, had initiated a wave of activity across Europe and the US, offering the potential for micro-mechanical models for plastic flow and its dependence on composition, temperature, time (strain-rate) and prior mechanical history. Fred became one of the principal players in the field, starting with his 1958 study of the deformation of polycrystals [1]. To understand his approach and his subsequent contributions it helps to have a picture of the intellectual climate of Göttingen and the excitement of generated by dislocation-plasticity at that time. This brief paper describes this context in which Fred's work should be viewed.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"34 ","pages":"Pages 32-34"},"PeriodicalIF":6.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095708","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}
Pub Date : 2025-01-01DOI: 10.1016/j.jmrt.2024.12.031
Yunyun Liu , Xianfei Ding , Lihong Wu , Xin Feng , Jiabin Zuo , Yunan Zhang , Lei Wen
Based on immersion weight loss and electrochemical methods, the corrosion behavior of cast Ti2AlNb alloy in HF–HNO3 solution was investigated. The corrosion effects of HF and HNO3 on Ti2AlNb alloy were elucidated by examining the impact of varying concentrations of HF and HNO3 in mixed pickling solution on corrosion rate and surface roughness, as well as comparing and analyzing changes in macroscopic surfaces, microscopic morphology, and three-dimensional morphology before and after pickling. The electrochemical behavior of Ti2AlNb alloys in different concentrations of HF and HNO3 solutions was revealed by measuring the OCP-time and polarization curves of Ti2AlNb alloys in HF–HNO3 mixed pickling solutions. The experimental results indicated that the corrosion rate of Ti2AlNb alloy increased linearly with the increasing concentrations of HF and HNO3. Surface roughness increases with higher HF content, but decreases with higher HNO3 content after reaching a certain maximum value. The high concentrations of HNO₃ exert a pronounced passivation effect, which results in a reduction of surface roughness. However, it also has the tendency to produce pitting corrosion in coarse O/α2 phases at grain boundaries and within the grain. Scanning Kelvin probe atomic force microscopy (SKPFM) combined with microstructural analysis revealed that the electrochemical system consisting of matrix B2 phase and secondary phase governs the high localized dissolution rate of Ti2AlNb alloy. Additionally, the segregation of elements at grain boundaries accelerates corrosion, leading to more severe degradation in those regions. This study provides an experimental basis for understanding the corrosion behavior of Ti2AlNb alloy in HF–HNO3 solution.
{"title":"Study of the corrosion behavior of cast Ti2AlNb alloy in HF–HNO3 solution","authors":"Yunyun Liu , Xianfei Ding , Lihong Wu , Xin Feng , Jiabin Zuo , Yunan Zhang , Lei Wen","doi":"10.1016/j.jmrt.2024.12.031","DOIUrl":"10.1016/j.jmrt.2024.12.031","url":null,"abstract":"<div><div>Based on immersion weight loss and electrochemical methods, the corrosion behavior of cast Ti<sub>2</sub>AlNb alloy in HF–HNO<sub>3</sub> solution was investigated. The corrosion effects of HF and HNO<sub>3</sub> on Ti<sub>2</sub>AlNb alloy were elucidated by examining the impact of varying concentrations of HF and HNO<sub>3</sub> in mixed pickling solution on corrosion rate and surface roughness, as well as comparing and analyzing changes in macroscopic surfaces, microscopic morphology, and three-dimensional morphology before and after pickling. The electrochemical behavior of Ti<sub>2</sub>AlNb alloys in different concentrations of HF and HNO<sub>3</sub> solutions was revealed by measuring the OCP-time and polarization curves of Ti<sub>2</sub>AlNb alloys in HF–HNO<sub>3</sub> mixed pickling solutions. The experimental results indicated that the corrosion rate of Ti<sub>2</sub>AlNb alloy increased linearly with the increasing concentrations of HF and HNO<sub>3.</sub> Surface roughness increases with higher HF content, but decreases with higher HNO<sub>3</sub> content after reaching a certain maximum value. The high concentrations of HNO₃ exert a pronounced passivation effect, which results in a reduction of surface roughness. However, it also has the tendency to produce pitting corrosion in coarse O/α<sub>2</sub> phases at grain boundaries and within the grain. Scanning Kelvin probe atomic force microscopy (SKPFM) combined with microstructural analysis revealed that the electrochemical system consisting of matrix B2 phase and secondary phase governs the high localized dissolution rate of Ti<sub>2</sub>AlNb alloy. Additionally, the segregation of elements at grain boundaries accelerates corrosion, leading to more severe degradation in those regions. This study provides an experimental basis for understanding the corrosion behavior of Ti<sub>2</sub>AlNb alloy in HF–HNO<sub>3</sub> solution.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"34 ","pages":"Pages 372-383"},"PeriodicalIF":6.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095866","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}
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