Effects of preferred orientation on the grain size dependence of yield strength in metals

Publisher Website
Google Scholar
Abstract
The Petch equation ([sgrave] = [sgrave]0 + kl −½) is applied rather widely in investigations of the sources of the variation of yield stress [sgrave] with grain diameter l in polycrystalline metals. In general, however, the behaviour of randomly oriented aggregates has been considered, so that [sgrave]0 and k are regarded as constant for a particular material. A preferred orientation of the crystals can influence both [sgrave]0 and k by altering the relationship between the applied stress and the shear stresses developed on active slip planes. Because k is affected by local orientation effects, it can change independently of [sgrave]0 if there is an alteration in the orientation relationships of adjacent grains. These effects of orientation will be particularly important in non-cubic metals, due to the small number of their slip systems. In magnesium extrusions considerable variations in [sgrave]0 and k were obtained by changing the direction of the applied stress relative to the extrusion axis and by changing the character of the preferred orientation.

This publication has 2 references indexed in Scilit: