Process method for casting aluminum silicon alloy by modification of rare earth

The invention discloses a process method for casting an aluminum silicon alloy by modification of rare earth, and belongs to the field of aluminum alloy casting. According to the process method, an Al-10%RE intermediate alloy serves as a modificator, and the cast aluminum-silicon alloy serves as a modified object. The process method specifically comprises the following steps that the aluminum-silicon alloy is heated and melted, the temperature is raised to 730-740 DEG C, stirring, refining and degassing and slag removal and are carried out, the aluminum-silicon alloy holds for 20-30 min whenthe temperature is kept, the Al-10%RE intermediate alloy of 1.5-3% is added and synchronously a melt is fully stirred and removes slag, the Al-10%RE intermediate alloy holds for 40-50 min when the temperature is raised to 750-760 DEG C, and when the temperature is 690-700 DEG C, molten metal is rapidly poured into a metal mold with the temperature of 160 DEG C-190 DEG C. According to the process method for casting the alum