The micromechanics of dislocation-loop emission were examined with the of determining the threshold condition associated with microvoid growth. The closed form of threshold stress was obtained for edge dislocation in the vicinity of cylindrical void in a general planar macroscopic stress state. The effects of surface energy and lattice friction were accounted for; the former was found to be significant. A prolate-to-oblate shape transition in uniaxial strain due to a higher driving force on slip plane transverse to the loading direction was observed. In the asymptotic condition of a large void, threshold condition was dictated by planar mean stress for general macroscopic stress state.

Threshold Condition of Dislocation Loop Emission from Microvoids. T.C.Tszeng: Journal of Applied Physics, 2008, 103[5], 053509