冷却速度对复杂铝合金铸件组织的影响  

Effect of Cooling Rate on Microstructure of Complex Aluminum Alloy Castings

作　　者：康永飞 李浩 白朴存[1] 崔晓明[1] KANG Yong-fei;LI Hao;BAI Pu-cun;CUI Xiao-ming(Inner Mongol University of Technology,Materials Science and Engineering College,Hohhot 010051,Inner Mongolia,China)

机构地区：[1]内蒙古工业大学材料科学与工程学院,内蒙古呼和浩特010051

出　　处：《铸造》2020年第1期40-45,共6页Foundry

基　　金：内蒙古自治区科技重大专项(RZ1800008226);内蒙古科技计划项目(RZ1800008229)。

摘　　要：研究了复杂铝合金铸件壁厚和局部放置冷铁对铸件冷却速度的影响,以及冷铁的放置对铸件中α-Al二次枝晶、共晶硅和富铁相的影响。结果表明,放置冷铁可以明显提高冷却速度,壁厚越小,效果越好;冷铁的放置使合金α-Al二次枝晶细小,粗大的片层状共晶硅变为较小的椭圆状;Mn元素与冷铁共同作用促使形成形态较小的树枝状α-Fe相。若冷却速度过大,富铁相为细小的针状β-Fe相。The study investigated the effects of wall thickness of complex aluminum alloy castings and metal chill placed at local areas on the cooling rate of castings, and the effect of chill on α-Al secondary dendrites, eutectic silicon and iron-rich phases in aluminum castings. The results show that the metal chill placed at local areas can significantly increase the cooling rate of castings, and the smaller wall thickness is, the more obvious the cooling effect will be. The use of metal chill can make α-Al secondary dendrites in the cast aluminum alloy finer, and the coarse lamellar eutectic silicon phase becomes smaller elliptical particle. Since the impurity Mn element interacts with the metal chill, a dendritic α-Fe phase with a small size was formed. If the cooling rate is rapid, the iron-rich phase will become a fine needle-like β-Fe phase.

关 键 词：冷却速度 α-Al二次枝晶 共晶硅 富铁相 

分 类 号：TGI46.21[金属学及工艺]