Variation of the second-phase morphology and its influence on fracture behavior of Al-Si alloy  

Al-Si合金第二相形貌变化及其对断裂行为的影响(英文)

作　　者：孙瑜[1] 陈晋[1] 孙国雄[1] 

机构地区：[1]东南大学材料科学与工程系

出　　处：《Journal of Southeast University(English Edition)》2004年第1期53-58,共6页东南大学学报（英文版）

摘　　要：Using an optical microscope and scanning electron microscope (SEM), the variation of eutectic Si morphology of Al-Si alloy in solution treatment was observed to study its influence on mechanical properties and fracture behavior. The results show that eutectic Si undergoes stubbing, necking, fragmentation, and growth in the initial stage (250 min); in the middle solution stage (250 to 400 min), the eutectic Si morphology has no significant change, only the degree of spheroidizing becomes higher; after 600 min, the growth of eutectic Si is a coarsening process controlled by diffusion and follows the Liftshitz-Slyozov-Wangner (LSW) model, and the eutectic Si morphology deteriorates due to the occurrence of facets and lap. Based on the quantitative measure and regression analysis, the eutectic Si morphology has a remarkable influence on mechanical properties and fracture behavior.用光学显微镜和扫描电镜 (SEM )观察Al Si合金中硅相形貌在固溶过程中的变化 ,并研究了此变化对合金力学性能和断裂行为的影响 .结果表明 :固溶初期 (2 5 0min) ,硅相发生缩颈、钝化、溶断并伴随长大 ;在固溶中期 (2 5 0～ 4 0 0min) ,其形貌没有发生显著变化 ,仅球化程度更高 ;6 0 0min后 ,硅相的长大是受扩散控制的粗化过程 ,且符合LSW粗化模型 ;同时由于出现棱角小面及搭接特征使硅相形貌有所恶化 .定量金相测量及回归分析说明硅相的形貌对合金的力学性能和断裂行为有显著影响 .

关 键 词：Al-Si alloy variation of Si phase mechanical properties fracture behavior 

分 类 号：TG146.21[一般工业技术—材料科学与工程]