Precipitate prediction model of Mg-xAl(x=3,6,9) alloys

A model was developed to predict the precipitation of Mg17Al12 in Mg-(3,6,9)wt%Al alloys. The phase equilibrium of the Mg-Al alloy system was calculated in detail by utilizing a phase diagram calculation commercial package and other thermodynamic data for Mg alloys. The precipitation kinetics of Al in Mg-(3,6,9)wt%Al alloys after different thermal treatments were studied by measuring electrical resistivity and hardness. The results obtained were explained by a model based on a simple nucleation and growth model and were compared with the measured precipitates volume fraction. And, the experimental results agreed on the thermodynamic data with the conditions of 12 hr for Mg-3Al, 30 min for Mg-6Al, 15 min for Mg-9Al alloys. Therefore, the model was applied to predict the effects of the precipitation of Mg17Al12.