MULTIPHASE DIFFUSION STUDY FOR Mg-Al BINARY ALLOY SYSTEM

摘要

Multiphase diffusion simulation and annealing experiments have been performed for Mg-Al binary alloys at various temperatures. Annealing experiments of Mg-3wt% Al and Mg-6wt% Al alloys were carried out at 330 and 400°C for various times and the change of concentration profiles of Al in grains were measured by Electron Probe Micro Analyzer (EPMA). In order to simulate this annealing process and understand the diffusion of Mg-Al alloys, diffusion model was developed by using Finite Difference Method (FDM) coded in FORTRAN. In the diffusion simulations, composition-independent inter-diffusion coefficients were used and the intermetallic phases were assumed to have equilibrium compositions.