Mass Transfer Model and Crystal Growth Equation for Nitridation Reactions of Al-Si-Mg Alloys

Mass transfer model and equation were established according to the characteristics of nitridation reactions of molten Al-Si-Mg alloys. It shows that nitridation rocess is divided into two stages: stage Ⅰ－AlN crystal growth with Si-enrichment; stage Ⅱ- co-growth of binary crystal AlN and Sicry. The rate of N atom diffusion is the key factor of controlling whole nitridation rate.