LI Qingsheng
,
(Chingshen Li)Taiyuan University of Technology
,
Taiyuan
,
China T.BRETHEAU Laboratory PMTM
,
CNRS
,
University Paris Nord Dept.of Mathematics and Mechanics
,
Taiyuan University of Technology
,
Taiyuan 030024
,
China
金属学报(英文版)
The effect of grain boundaries on cyclic deformation and fatigue crack growth in aluminum bicrystals has been studied.The effect of a grain boundary is restricted in a narrow area, termed as grain boundary affecting zone(GBAZ),where the incompatible plastic strain treats internal stress which conversely promotes inhomogeneous slip in the area and grain boundary cracking.As an extended stage I crack initiated from a notch approaches the grain boundary under a constant cyclic stress,the crack front branches splits into several pieces, meanwhile,the growth rate of the crack reduces to a minimum value at the center of the GBAZ.Such microstructure-sensitive growth of extended stage I cracks is mainly attributed to the grain boundary-induced crack tip sheilding.
关键词:
compatibility
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