Dependence of microtextural orientation on applied fatigue loading in shot-peened aluminium

摘要

It is well known that cold-work induced residual stresses can be used to influence the fatigue life of strain-hardening metals. The effect of load cycles on stress fields in such materials is less well understood; reports of stress relaxation at various proportions of fatigue life can be found in the literature but little correlation is found between experiments. The phenomenon of strain re-orientation was noted in as a function of orientation of maximum principal strain with applied loading. Residual strains evaluated over a short range (of the order of a few grains) are significantly influenced by the order and orientation of those grains, described as microtexture. To accurately describe the cyclic behaviour of aluminium treated with shot peening it is necessary to develop an understanding of the relationship between residual stress, microtextural orientation and applied loading.