摘要
通过SEM原位拉伸研究了全片层Ti-46.5Al-2.0Cr-1.5Nb-1.0V合金的显微组织与断裂行为的关系。通过热处理手段获得可区分晶粒尺度和片层厚度的全片层组织。研究表明,随着晶粒尺度的增大,裂纹扩展路径由平直变得曲折,断裂方式由沿片层界面和沿晶断裂变为穿片层断裂。随着片层厚度的减小,韧带的刚性增强,塑性变形减小,增韧效果得到改善。在全片层组织中,微裂纹在α_2/γ片层界面形核。
The relationships between microstructure and fracture behavior of fully lamellar Ti-46.5Al-2.0Cr-1.5Nb-1.0V alloys have been studied by SEM observation for in-situ tension. The fully lamellar microstructures with different grain size and lamellar spacing were obtained by heat treatment. The results show that as the grain size increase, the propagation paths of cracks become tortuous, and interface de-lamination and inter-granular fracture are substituted by a trans-lamellar fracture. The rigidity of ligaments increases with the decrease of the lamellar spacing. So the amount of plastic deformation of ligaments decreases, and the alloys are toughened. Microcracks nucleate on lamellar interface of fully lamellar γ-TiAl alloys.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2004年第2期196-200,共5页
Rare Metal Materials and Engineering
