Molecular dynamics simulation of fracture behaviors of <110> tilt grain boundaries in γ-TiAl

作     者：赵文娟 徐东生 赵敬伟 王皞 Wen-juan ZHAO;Dong-sheng XU;Jing-wei ZHAO;Hao WANG

作者机构：湘潭大学材料设计及制备技术湖南省重点实验室湘潭411105 湘潭大学机械工程学院湘潭411105 中国科学院金属研究所沈阳110016 School of Mechanical Materials and Mechatronic Engineering University of Wollongong NSW 2522 Australia 

基　　金：Project(51201147)supported by the National Natural Science Foundation of China Project(14JJ6016)supported by the Natural Science Foundation of Hunan Province,China Project(INFO-115-B01)supported by the Informalization Construction Project of Chinese Academy of Sciences,China 

出 版 物：《Transactions of Nonferrous Metals Society of China》 (中国有色金属学报（英文版）)

年 卷 期：2014年第24卷第11期

页      码：3645-3651页

摘      要：Molecular dynamics(MD) simulations were carried out to study the fracture behaviors of several symmetric tilt grain boundaries in γ-Ti Al bicrystals with misorientation axes. Tensile deformation along direction perpendicular to grain boundary was simulated under various strain rates and temperatures. The results indicate that the relative orientation of the grains and the presence of certain atom units are two critical factors of the interface structure affecting the stress required for dislocation nucleation. Dislocations nucleate and extend at or near the symmetric tilt grain boundaries during the tensile deformation of Σ3(111) 109.5°, Σ9(221) 141.1° and Σ27(552) 148.4° interfaces. For Σ27(115) 31.6° and Σ11(113) 50.5° interfaces, the interfaces fractured directly in a cleavage manner due to no dislocation emitted from the boundary. The tensile fracture mechanisms of the bicrystals are that micro-cracks nucleate at the grain boundary and propagate along the interface. The variance of crack propagation is whether there is accommodation of plastic region at the crack tips.

主 题 词：gamma TiAl alloy tilt grain boundary molecular dynamics tensile deformation fracture 

学科分类：08[工学] 080502[080502] 0805[工学-能源动力学] 

核心收录：

D　O　I：10.1016/S1003-6326(14)63510-X

馆 藏 号：203998224...