The mechanism of clustering in supersaturated solid solutions of A1-Mg 2Si alloys

Abstract

The early stages of the precipitation in the Al-Mg 2Si system were investigated by isothermal resistivity measurements. The process of clustering was studied over a wide range of temperature (between − 50 and 200°C) after two different quenching methods. The continuous observation of the resistivity led to the investigation of the kinetics of the process near room temperature. The effect of preageing on the subsequent ageing was also studied by electrical resistivity and microhardness measurements. On the basis of the experimental results a new model is suggested for the process of clustering. The most important feature of the process seems to be the decisive role of Si.