Fatigue-induced Precipitation in Meta-stable β-Brass

Abstract

A NUMBER of instances have been recorded in which metallurgical changes have occurred due to fatigue stressing which would not have occurred in the same time at the same temperature in the absence of the fatigue stress1–4. The changes are similar to those produced by heating and appear to be caused by either an increased diffusion-rate or an increase in nucleation sites. Two most obvious examples are the apparent over-ageing of certain aluminium alloys investigated by Hanstock1,2 and the virtual removal of the long incubation time observed in normal aged aluminium alloys reported by Stubbington4.