Evidence of void nucleation and growth on planar slip bands in a Nb-Cr-Ti alloy

Dimpled fracture via void nucleation, growth, and coalescence is common in alloys containing hard particles or inclusions, which act as void nucleation sites. Void-covered fracture surfaces have also been observed in planar slip materials. However, the process by which dimples form in the planar slip materials is not understood because these materials generally do not contain hard particles or inclusions. An intersecting slip process was recently proposed as a possible mechanism for the formation of dimpled fracture in the planar slip materials. In this article, experimental evidence of void nucleation and growth on planar slip bands in a Nb-Cr-Ti solid-solution alloy (Nb-13Cr-37Ti, in at. pet) is presented. The experimental observations are compared against the intersecting slip model and a Peierls stress calculation to elucidate the mechanism of dimpled fracture in planar slip materials.