It is the first in this paper to apply thermodynamical analysis to crystallization of the Al-Si eu-tectic alloys. The results of analysis show that wty the silicon separatas out as a preliminary phase

and why the Al-Si alloys have their own pseudoeutectic structures are all for thermodynamical reasons. Finally it comes to the conclusion that for improving the quality of products

application of refining to Al-Si alloys for ridding them of gases and inclusions is of great importance.