In the present study,molecular dynamic simulation(MD)was used to investigate the plastic deformation process of the Fe-Mn alloys with different Mn contents.The influences of Mn contents ranging from 10%to 30%(at%)on t...In the present study,molecular dynamic simulation(MD)was used to investigate the plastic deformation process of the Fe-Mn alloys with different Mn contents.The influences of Mn contents ranging from 10%to 30%(at%)on the deformation behavior and the controlling mechanism of the Fe-base alloys were analyzed.The results show that phase transformations and{112}<111>_(BCC)deformation twinning occur in all Fe-Mn alloys but follow different deformation paths.In the Fe-10%Mn alloy the deformation twinning mechanism obeys the FCC-related path,the Fe-20%Mn alloy involves both the FCC-and HCP-related paths,and the deformation of the Fe-30%Mn alloy is dominated by the HCP-related twinning path.The addition of Mn can increase the stacking fault energy and retard the activation of slip systems as well as the formation of stacking faults.Thus,a higher content of Mn can delay the FCC®ε-martensite and the subsequentε-martensite®BCC phase transition at the intersection of twoε-martensitic bands.Therefore,the addition of Mn alloying element increases the yield strength and reduces the elastic modulus of the Fe-Mn alloys.The formation of deformation twins will contribute to the work-hardening effect and delay the necking and fracture of alloys.It is expected that the results in the present study will provide theoretical reference for the design and optimization of high-performance steels.展开更多
2024年7月26日,Science刊发了北京科技大学新金属材料国家重点实验室陈克新研究员团队联合北京工业大学王金淑教授团队,以及中国香港大学黄明欣教授的最新科研成果“Borrowed dislocations for ductility in ceramics”。该研究在实现...2024年7月26日,Science刊发了北京科技大学新金属材料国家重点实验室陈克新研究员团队联合北京工业大学王金淑教授团队,以及中国香港大学黄明欣教授的最新科研成果“Borrowed dislocations for ductility in ceramics”。该研究在实现陶瓷压缩塑性的基础上,首创性地提出了向金属“借位错”的策略,进一步实现了陶瓷的大变形拉伸塑性,陶瓷的拉伸形变量可达39.9%,强度约为2.3GPa,颠覆了人们关于“陶瓷不可能具有拉伸塑性”的一贯认知。展开更多
基金Project(51901248)supported by the National Natural Science Foundation of ChinaProject(2023JJ40742)supported by the Natural Science Foundation of Hunan Province,China。
文摘In the present study,molecular dynamic simulation(MD)was used to investigate the plastic deformation process of the Fe-Mn alloys with different Mn contents.The influences of Mn contents ranging from 10%to 30%(at%)on the deformation behavior and the controlling mechanism of the Fe-base alloys were analyzed.The results show that phase transformations and{112}<111>_(BCC)deformation twinning occur in all Fe-Mn alloys but follow different deformation paths.In the Fe-10%Mn alloy the deformation twinning mechanism obeys the FCC-related path,the Fe-20%Mn alloy involves both the FCC-and HCP-related paths,and the deformation of the Fe-30%Mn alloy is dominated by the HCP-related twinning path.The addition of Mn can increase the stacking fault energy and retard the activation of slip systems as well as the formation of stacking faults.Thus,a higher content of Mn can delay the FCC®ε-martensite and the subsequentε-martensite®BCC phase transition at the intersection of twoε-martensitic bands.Therefore,the addition of Mn alloying element increases the yield strength and reduces the elastic modulus of the Fe-Mn alloys.The formation of deformation twins will contribute to the work-hardening effect and delay the necking and fracture of alloys.It is expected that the results in the present study will provide theoretical reference for the design and optimization of high-performance steels.
文摘2024年7月26日,Science刊发了北京科技大学新金属材料国家重点实验室陈克新研究员团队联合北京工业大学王金淑教授团队,以及中国香港大学黄明欣教授的最新科研成果“Borrowed dislocations for ductility in ceramics”。该研究在实现陶瓷压缩塑性的基础上,首创性地提出了向金属“借位错”的策略,进一步实现了陶瓷的大变形拉伸塑性,陶瓷的拉伸形变量可达39.9%,强度约为2.3GPa,颠覆了人们关于“陶瓷不可能具有拉伸塑性”的一贯认知。
