, La 1ère Ecole d’Automne sur les Matériaux Emergents(EAME)

Taille de police: 
Precipitation and kinetics of second phase γMg17Al12 in AZ91 Alloy

Dernière modification: 2017-11-19


This study investigated the effect of aging on the precipitation and kinetics of second phase Mg17Al12 in AZ91 magnesium alloy (Mg-9wt%Al-1wt%Zn), using Differential Scanning Calorimitry analysis (DSC). DSC were carried out on sample starting from room temperature to 400 C, with heating rates from 10 to 30 C.min-1. The results were supplemented by measured the average of activation energies, using isothermal treatments by Johnson−Mehl−Avrami (JMA) and Ligero methods and by non-isothermal treatments using Ozawa, Boswell, Kissinger and Mahadavan methods, were around 67 and 60 kJ/mol, respectively. The numerical factor m and The Avrami parameter n is estimate to be approximately equal to 3 and 2.79 correspondingly. The growth morphology parameters n and m were both found to be equal to 3, demonstrating that bulk nucleation with constant number of nuclei was dominant in three-dimensional (polyhedron) controlled by interface reaction.