Precipitation kinetics in A16061 and in an A16061-alumina particle composite

Differential scanning calorimetry (DSC) was used to study the precipitation kinetics of metastable phases in an Al6061 alloy and a 20 vol % alumina pa rticle reinforced Al6061 composite. The thermal effects in the DSC traces w ere analysed quantitatively. The kinetic parameters for the phase transform ations in the Al6061 alloy a nd composite were calculated using the varying heating rate method and the Kissinger approach. It was found that the over all age-hardening sequence of the Al6061 alloy did not change due to the ad dition of Al2O3 particles, but the volume fractions of the various phases a nd the precipitation kinetics of some of the phases were modified. The prec ipitation transformations of the metastable phases in both the Al6061 and t he composite obey an n-order kinetic model. (C) 1998 Kluwer Academic Publis hers.