作　　者： ; ; ; ; ; ; ; ;

机构地区： 江苏大学材料科学与工程学院

出　　处： 《中国有色金属学报》 2006年第12期2060-2065,共6页

摘　　要： 用A356-Zr（CO2）2组元通过熔体直接反应法原位合成了Al3Zr和Al2O3颗粒增强铝基复合材料，在720℃时进行常规金属模浇注和挤压铸造成型。挤压铸造是复合材料在高压下的结晶凝固和塑性变形和强制补缩-密实两过程的复合，增加复合材料熔点，改善模壁和熔体热交换条件，增加基体形核率。与金属模铸造试样的组织对比表明：由于复合材料的高致密度和细晶强化，挤压铸造成型复合材料组织中气泡和缩孔等浇注缺陷减少了，而组织致密度提高了，基体晶粒度减小2～3倍，复合材料的抗拉强度和延伸率分别为345MPa和15．07％，较金属模成型复合材料分别提高1．6和2．15倍，且挤压铸造复合材料干滑动磨损性能明显提高。 The A356-Zr（CO3）2 components were used to synthesize in-situ AlsZr, Al2Os particulates reinforced aluminum matrix composites, which were cast by conventional permanent mold and squeeze casting at 720 ℃ respectively. Squeeze casting refers to crystallization, solidification and plastic deforming at high pressure, which combines the compulsory feeding and densification. It enhances the melting point of composites and nucleation rate and improves the heat exchange condition between mold wall and melt. Compared with composites cast by permanent mold, the amount of bubbles and shrinkage holes decreases largely in composites cast by squeeze casting. The tightness of microstructures increases. Meanwhile, the grain size of matrix is decreased by 2 -3 times. The tensile strength and elongation are 345 MPa and 15.07%, respectively, which are increased by 1.6 and 2.15 times. The dry sliding prop- erty is enhanced largely. The excellent properties are attributed to high tightness and grain strengthening.

关 键 词： 颗粒增强铝基复合材料 挤压铸造 凝固组织 抗拉强度 干滑动磨损性能

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]