Investigation on Melting Phenomena Generated during Dynamic Formation of Al-Based Coating on Magnesium Alloy

The deposition behavior of Al-Si particle on magnesium alloy by supersonic particles deposition was investigated by numerical stimulation. The results demonstrated that critical velocity of sprayed particle reduced as its initial temperature increased; Temperature at interface increased rapidly and reached to the value higher than melting point of Al-Si particle and ZM5 magnesium substrate, which predicts the melting possibility for collision interface. Morphology and microstructure of Al-Si coating on magnesium alloy were analyzed by SEM and TEM. The results indicated that there existed large amount of nano/micro-scale grains produced by sputtering and impacting of the melting Al-Si jet. And obvious interface belt had been formed at brim of the deposited particles, nanocrystalline phase region generated by rapid solidification of melting Al-Si particles, justified the occurrence of interface melting phenomena.