【摘要】 利用半固态受控扩散凝固技术（CDS）和触变成形技术制备了Al-8Si（质量分数，%）合金，对比研究了铸态、CDS态及触变态合金的组织演变及其与冲击性能的关联性。通过光学显微镜（OM）、X射线衍射仪（XRD）、扫描电镜（SEM）及夏比冲击试验分别对3种状态合金的微观组织和冲击功进行了测试和表征。结果表明，铸态合金组织由粗大的α-Al树枝晶及针状共晶Si构成，CDS态合金则由球状α-Al及针状共晶Si构成，而触变态合金内部组织呈现球形α-Al和短棒状共晶组织。冲击性能测试结果显示，触变合金呈现出最高的冲击功（13.2 J），相较于铸态合金提高了523%，这主要归因于共晶Si的球化现象。更多还原

【Abstract】 Al-8 Si alloy was prepared by semi-solid controlled diffusion solidification technology(CDS) and thixoforming technology, and the microstructure evolution of as-cast, CDS and thixotropic alloy as well as the correlation with impact behavior was investigated comparatively. Microstructure and impact energy of alloys were tested and characterized by OM, XRD, SEM and Charpy impact tests. The results indicate that as-cast alloy is composed of coarse α-Al dendrites and needlelike eutectic silicon, and CDS alloy is composed of spherical α-Al and needlelike eutectic silicon, while thixotropic alloy exhibits spherical α-Al and short rod-like eutectic structure. The impact property test results reveal that the thixotropic alloy exhibits the highest impact energy(13.2 J), which is 523% higher than that of as-cast one. The excellent impact toughness is mainly attributed to the spheroidization of eutectic silicon.更多还原