Intergranular Stresses

Abstract

Intergranular residual strains exist within the grains of a polycrystalline aggregate with a length scale of the order of the grain size. They originate in different rates of thermal expansion in different phases or different crystallographic directions or in the anisotropy of the elastic and plastic response to applied stress as determined by the crystallographic orientation of the grains. There is a semiquantitative understanding of the signs and magnitudes of the strains and stresses. The industrial impact of these strains is noted. The importance of the intergranular strains for correctly interpreting measurements of strain by diffraction in terms of engineering stresses is emphasised.