The role of γ/γ interfacial spacing on the tensile behavior in lamellar TiAl alloy via molecular dynamics simulations  

γ/γ界面间距对层状TiAl合金拉伸性能影响的分子动力学研究

作　　者：Xiong Zhou Shiping Wang Zhongtao Lu Xiege Huang Xiaobin Feng Jiayi Fu Wenjuan Li Pengcheng Zhai Guodong Li 周雄;王世平;陆忠涛;黄写格;冯骁斌;付嘉怡;李文娟;翟鹏程;李国栋

机构地区：[1]Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics,School of Science,Wuhan University of Technology,Wuhan 430070,China [2]State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China

出　　处：《Acta Mechanica Sinica》2025年第2期1-6,共6页力学学报(英文版)

基　　金：This work was supported by the National Natural Science Foundation of China(Grant Nos.92163215,92163212,and 92163119);the Knowledge Innovation Program of Wuhan-Basic Research(Grant No.2022010801010177);the National Innovation and Entrepreneurship Training Program for College Students(Grant No.S202310497212).

摘　　要：The lamellar microstructure is one of the most typical microstructures of TiAl alloys.There are threeγ/γinterfaces with different microstructures in lamellarγ-TiAl alloys.In this work,we investigated the deformation processes of lamellarγ-TiAl alloys with different interfacial spacing(λ)via uniaxial tensile loading using molecular dynamics simulations,including true twin(TT),pseudo-twin(PT),rotational boundary(RB),and the mixed structure(TT∥PT∥RB).The results show that in all lamellarγ-TiAl samples,the Shockley partial dislocation prefers to nucleate in the region between two neighboring interfaces.Then,dislocations move towards,crossing theγ/γinterface.Finally,the dislocation slippage leads to the destruction of the interface,resulting in cracks and structural failure.With the decrease ofλ,the ultimate strength slightly increases in the TT or PT structure ofγ-TiAl,which follows the Hall-Petch relation.But in general,the interfacial spacing has a slight effect on the ultimate strengths of these four structures ofγ-TiAl.片层组织是TiAl合金最典型的微观结构之一.在层状γ-TiAl合金中存在三种不同的γ/γ界面.本文采用分子动力学模拟方法研究了不同界面间距(λ)的层状γ-TiAl合金在单轴拉伸载荷下的变形过程,包括真孪晶(TT)、伪孪晶(PT)、旋转边界(RB)和混合结构(TT∥PT∥RB).结果表明:在所有层状γ-TiAl样品中,Shockley不全位错倾向于在相邻界面之间的区域形核,然后位错移动穿过γ/γ界面,最后,位错的滑移导致了界面的破坏,从而产生裂纹,结构破坏.随着λ的减小,γ-TiAl的TT或PT结构的极限强度略有增加,符合Hall-Petch趋势.但总的来说,界面间距对γ-TiAl的四种结构的极限强度影响不大.

关 键 词：Lamellarγ-TiAl alloys γ/γinterface Ultimate strength Interfacial spacing 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TG146.2[金属学及工艺—金属材料]