采用固溶处理,研究CDS制备过共晶Al-18Si合金中初生Si相与共晶Si相形貌的变化.结果表明,随着固溶温度的升高和固溶时间的延长,初生Si相平均尺寸显著减小,经570℃×6h固溶后,合金中初生Si相尺寸为20.78 μm;共晶Si的变化趋势和初生Si相似,均由针状逐渐粒化为近球状,经570℃×6h固溶后,合金中共晶Si尺寸为5.44μm,且分布趋向均匀.“,”Effects of solution treatment on the evolution of microstructure of primary Si and eutectic Si in Al-18Si alloy prepared by CDS were investigated.The results show that the average size of primary Si in Al-18Si is decreased significantly with the increase of temperature and time,where primary Si size reaches 20.78 μm at 570 ℃ for 6 h solution treatment.The eutectic Si is also refined from acicular structure to near-spheroidization with increasing in temperature and time,where the average size of eutectic Si phase is decreased from 25.57 μm to 5.44 μm with more uniform distribution.