Diffusion and mechanical properties of Ti2AlNb and TA15 interface: From experiments to molecular dynamics. (January 2022)

• Record Type: Journal Article
• Authors: Li, Ping; Wang, Lusheng; Wang, Bin; Yan, Siliang; Meng, Miao; Ji, Xiaohu; Xue, Kemin
• Is Part Of: Vacuum. Volume 195(2022)
• Publication Date: 2022-01
• Subjects: Ti2AlNb/TA15 interface -- Diffusion -- Microstructures -- Mechanical properties -- Molecular dynamics; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2021.110637
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: The experiments and molecular dynamics simulations were employed to further understand the morphology evolution and failure mechanism of the TA15/Ti2 AlNb interface. The results show that the asymmetric diffusions, caused by the difference of the diffusion coefficient and crystal structure, have played a significant role in the microstructure and mechanical properties. The diffusivity of Ti elements from TA15 was much better than those Nb and Al from Ti2 AlNb base alloy owing to its higher diffusion coefficient. The macro joints are brittle fractures near the TA15 base zone, and excessive holding time will reduce the tensile strength and plasticity of the joint while increasing the temperature can enhance the strength and plasticity due to the promotion of diffusion and improvement of the microstructure. However, the nano joints are ductile failures owing to size effects. Time has little effect on the mechanical properties of nano joint, while an increase in temperature could improve the strength and plasticity. The combination of MD simulations and experiments provides new approaches for the study of deformation mechanisms and microstructure evolution. Highlights: Element diffusion and distributions were investigated from the nanoscale to the microscale. The asymmetric diffusion was revealed by the diffusion coefficient and crystal structure. Two fracture behavior and mechanism of the joint were proposed under the different scale. The fracture mechanism was determined by atomic diffusion and interface morphology.