本文对Al-18％Si过共晶活塞合金的组织和性能作了初步研究,结果表明:(1)用磷和硫联合变质,可使初晶硅尺寸细化到20μ,共晶硅同时得到细化;(2)经合金化和热处理后,室温抗拉强度可达26—28kg/mm~2,不仅达到国内普遍生产的共晶活塞合金的标准,而且切削性能良好。因此,把本合金应用于生产是可能的。 In this paper, the microstructure and properties of Al-18% Si hypereutectic Piston alloy have been studied. The results show that: (1) The combination of phosphorus and sulfur modifies the size of primary silicon to 20μ, (2) After the alloying and heat treatment, the tensile strength at room temperature can reach 26-28kg / mm ~ 2, not only meet the standard of eutectic piston alloy commonly produced in China, but also the cutting performance is good. Therefore, the alloy used in the production is possible.