CALORIMETRIC ANALYSIS OF FORMATION / DISSOLUTION OF GUINIER-PRESTON ZONES IN AN Al-Zn-Mg ALLOY

Abstract

The formation and dissolution of solute clusters, Guinier-Preston Zones (GPZ), in an Al-Zn-Mg alloy are studied using Differential Scanning Calorimetry and Vickers microhardness determinations. The GPZI are formed under aging at room temperature, and its dissolution together with the GPZII formation occurs under continuous heating between 50°C and 150°C.  By means of a quantitative analysis of the thermograms, the kinetics of ZGPI formation was evaluated.