Molecular Dynamics Simulation of the Tensile Deformation of <110> Tilt Grain Boundaries in Gamma TiAl

摘要：

Molecular dynamics (MD) simulations are carried out to study the tensile deformation of several symmetric tilt grain boundaries in gamma TiAl bicrystals with <110> misorientation axes. Tensile deformation along direction perpendicular to grain boundary is simulated under various strain rates and temperatures. The results indicate that the relative orientation of the grains and the presence of certain structural units are two critical attributes of the interface structure affecting the stress required for dislocation nucleation. Aside from the sigma 11 (113) boundary, dislocations nucleate at or near the symmetric tilt grain boundaries during the tensile deformation. Micro-cracks nucleate at the grain boundary due to the accumulation of dislocations and the interaction between dislocations and boundary. Large amount of plastic deformation occurred around the fracture surface,and the cracks propagated perpendicular to the tensile direction. For the sigma 11 (113) boundary.no dislocation emitted from the boundary before and after yielding,and the bicrystal cleavages directly on the interface.

关键词： Gamma TiAl tilt grain boundary molecular dynamics simulation tensile deformation fracture

作者: W. J. Zhao D. S. Xu H. Wang R. Yang

作者单位: Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 , China

会议类型: 国际会议

会议名称: The 12th World Conference Titanium(第十二届世界钛会 Ti-2011)

会议地点: 北京

会议语种:英文

页码: 1563-1566

在线出版日期: 2011-06-19（万方平台首次上网日期，不代表论文的发表时间）