Thermodynamic reversibility and irreversibility of the reverse transformation in stabilized Cu-Zn-Al martensite

Abstract

[eng] It has been shown that both pinning- (mechanical) and reordering-induced (chemical) stabilization components contribute to the overall stabilization effect. An algorithm has been developed for quantitative analysis of the chemical and mechanical stabilization components, using routine calorimetry results. The basic idea underlying this algorithm is that chemical and mechanical stabilization components stem, respectively, from the factors, affecting thermodynamically reversible and irreversible factors during the first reverse transformation of the stabilized martensite. On a thermodynamical level, application of the suggested algorithm has been illustrated using experimental calorimetry results for a Cu–Zn–Al alloy. Here we report analysis of pinning and reordering processes on a microscopic scale, using experimental data on non-linear anelasticity in the same Cu–Zn–Al alloy to track different spatial and temporal localization of these processes during martensite ageing.