中国物理B ›› 2022, Vol. 31 ›› Issue (4): 46105-046105.doi: 10.1088/1674-1056/ac1f0b

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Evolution of defects and deformation mechanisms in different tensile directions of solidified lamellar Ti-Al alloy

Yutao Liu(刘玉涛)1, Tinghong Gao(高廷红)1,†, Yue Gao(高越)1, Lianxin Li(李连欣)1, Min Tan(谭敏)1, Quan Xie(谢泉)1, Qian Chen(陈茜)1, Zean Tian(田泽安)1,2, Yongchao Liang(梁永超)1, and Bei Wang(王蓓)1   

  1. 1 Institute of New Optoelectronic Materials and Technology, College of Big Data and Information Engineering, Guizhou University, Guiyang 550025, China;
    2 College of Computer Science and Electronic Engineering, Hunan University, Changsha 410082, China
  • 收稿日期:2021-07-03 修回日期:2021-08-10 接受日期:2021-08-19 出版日期:2022-03-16 发布日期:2022-03-10
  • 通讯作者: Tinghong Gao E-mail:gaotinghong@sina.com
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 51761004, 51661005, and 11964005), Industry and Education Combination Innovation Platform of Intelligent Manufacturing and Graduate Joint Training Base at Guizhou University (Grant No. 2020-520000-83-01-324061), the Guizhou Province Science and Technology Fund, China (Grant Nos. ZK[2021] 051,[2017] 5788, and J[2015] 2050), High Level Creative Talent in Guizhou Education Department of China, and the Cooperation Project of Science and Technology of Guizhou Province, China (Grant No. LH[2016] 7430).

Evolution of defects and deformation mechanisms in different tensile directions of solidified lamellar Ti-Al alloy

Yutao Liu(刘玉涛)1, Tinghong Gao(高廷红)1,†, Yue Gao(高越)1, Lianxin Li(李连欣)1, Min Tan(谭敏)1, Quan Xie(谢泉)1, Qian Chen(陈茜)1, Zean Tian(田泽安)1,2, Yongchao Liang(梁永超)1, and Bei Wang(王蓓)1   

  1. 1 Institute of New Optoelectronic Materials and Technology, College of Big Data and Information Engineering, Guizhou University, Guiyang 550025, China;
    2 College of Computer Science and Electronic Engineering, Hunan University, Changsha 410082, China
  • Received:2021-07-03 Revised:2021-08-10 Accepted:2021-08-19 Online:2022-03-16 Published:2022-03-10
  • Contact: Tinghong Gao E-mail:gaotinghong@sina.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 51761004, 51661005, and 11964005), Industry and Education Combination Innovation Platform of Intelligent Manufacturing and Graduate Joint Training Base at Guizhou University (Grant No. 2020-520000-83-01-324061), the Guizhou Province Science and Technology Fund, China (Grant Nos. ZK[2021] 051,[2017] 5788, and J[2015] 2050), High Level Creative Talent in Guizhou Education Department of China, and the Cooperation Project of Science and Technology of Guizhou Province, China (Grant No. LH[2016] 7430).

摘要: Two-phase γ-TiAl/α2-Ti3Al lamellar intermetallics have attracted considerable attention because of their excellent strength and plasticity. However, the exact deformation mechanisms remain to be investigated. In this paper, a solidified lamellar Ti-Al alloy with lamellar orientation at 0°, 17°, and 73° with respect to the loading direction was stretched by utilizing molecular dynamics (MD) simulations. The results show that the mechanical properties of the sample are considerably influenced by solidified defects and tensile directions. The structure deformation and fracture were primarily attributed to an intrinsic stacking fault (ISF) accompanied by the nucleated Shockley dislocation, and the adjacent extrinsic stacking fault (ESF) and ISF formed by solidification tend to form large HCP structures during the tensile process loading at 73°. Moreover, cleavage cracking easily occurs on the γ/α2 interface under tensile deformation. The fracture loading mechanism at 17° is grain boundary slide whereas, at 73° and 0°, the dislocation piles up to form a dislocation junction.

关键词: molecular dynamics simulation, solidified lamellar Ti-Al alloy, tensile directions, γ/α2 interface

Abstract: Two-phase γ-TiAl/α2-Ti3Al lamellar intermetallics have attracted considerable attention because of their excellent strength and plasticity. However, the exact deformation mechanisms remain to be investigated. In this paper, a solidified lamellar Ti-Al alloy with lamellar orientation at 0°, 17°, and 73° with respect to the loading direction was stretched by utilizing molecular dynamics (MD) simulations. The results show that the mechanical properties of the sample are considerably influenced by solidified defects and tensile directions. The structure deformation and fracture were primarily attributed to an intrinsic stacking fault (ISF) accompanied by the nucleated Shockley dislocation, and the adjacent extrinsic stacking fault (ESF) and ISF formed by solidification tend to form large HCP structures during the tensile process loading at 73°. Moreover, cleavage cracking easily occurs on the γ/α2 interface under tensile deformation. The fracture loading mechanism at 17° is grain boundary slide whereas, at 73° and 0°, the dislocation piles up to form a dislocation junction.

Key words: molecular dynamics simulation, solidified lamellar Ti-Al alloy, tensile directions, γ/α2 interface

中图分类号:  (Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.))

  • 61.72.Ff
83.50.-v (Deformation and flow ?) 81.40.Lm (Deformation, plasticity, and creep) 31.15.xv (Molecular dynamics and other numerical methods)