Effects of cooling rate on solution heat treatment of as-cast A356 alloy  

凝固冷却速率对铸态A356铝合金固溶热处理的影响（英文）

作　　者：杨长林[1] 李远兵[1] 党波[1] 吕贺宾 刘峰[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第10期3189-3196,共8页中国有色金属学报（英文版）

基　　金：Project(3102014KYJD002)supported by the Fundamental Research Funds for the Central Universities of China;Projects(50901059,51431008,51134011)supported by the National Natural Science Foundation of China;Project(2011CB610403)supported by the National Basic Research Program of China;Project(51125002)supported by the China National Funds for Distinguished Young Scientists;Project(JC20120223)supported by the Fundamental Research Fund of Northwestern Polytechnical University,China

摘　　要：The effect of cooling rate of the solidification process on the following solution heat treatment of A356 alloy was investigated,where the cooling rates of 96 K/s and 3 K/s were obtained by the step-like metal mold.Then the eutectic silicon morphology evolution and tensile properties of the alloy samples were observed and analyzed after solution heat treatment at 540 °C for different time.The results show that the high cooling rate of the solidification process can not only reduce the solid solution heat treatment time to rapidly modify the eutectic silicon morphology,but also improve the alloy tensile properties.Specially,it is found that the disintegration,the spheroidization and coarsening of eutectic silicon of A356 alloy are completed during solution heat treatment through two stages,i.e.,at first,the disintegration and spheroidization of the eutectic silicon mainly takes place,then the eutectic silicon will coarsen.通过对凝固冷却速度分别为96K/s和3K/s的阶梯模具制备的A356铝合金在540°C下进行固溶热处理,观察和分析该合金经过不同时间固溶处理后共晶硅形貌和拉伸性能的变化,研究凝固冷却速率对A356铝合金固溶热处理的影响。结果表明,凝固过程的冷速不仅能有效地改变合金中共晶硅的形貌,而且高的凝固冷速能缩短合金的固溶热处理时间、加速共晶硅形貌的演变和提高拉伸性能。而A356铝合金中共晶硅的断裂、球化和粗化行为在固溶热处理过程中通过先后两个阶段完成:首先主要是共晶硅的断裂和球化,随后是共晶硅的粗化。

关 键 词：A356 aluminum alloy solution heat treatment eutectic silicon cooling rate 

分 类 号：TG292[金属学及工艺—铸造] TG166.3