稀土钇对A356合金显微组织和拉伸性能的影响  

Effect of Rare Earth Y on Microstructure and Tensile Properties of A356 Alloy

作　　者：汪长勤[1] 赵玉涛[1] 张松利[1] 陈刚[1] 

机构地区：[1]江苏大学材料科学与工程学院,镇江212013

出　　处：《机械工程材料》2010年第1期13-16,共4页Materials For Mechanical Engineering

基　　金：国家863高新技术研究发展计划资助项目(2007AA03Z5481);江苏省六大人才高峰项目(06-D-021);江苏省科技成果转化项目(BA2005054);江苏省高技术研究项目(BG2005026);教育部科技研究重点项目(2070381)

摘　　要：运用光学显微镜、扫描电镜和万能电子拉伸试验机等研究了稀土元素钇对A356合金显微组织和拉伸性能的影响。结果表明:稀土钇是A356合金的一种优良变质剂,不但能使初生的α-Al晶粒变得圆整细小,二次枝晶间距减小,而且能使共晶硅由粗大的板条状转变为细小的颗粒状或纤维状;当加入0.4%钇后,A356合金的抗拉强度和伸长率分别达到了298 MPa和9.5%,比未添加钇的合金分别提高了29.6%和21.5%。The effect of rare earth Y on the microstructure and tensile properties of A356 alloy was studied by using OM, SEM and tensile testing machine. The results indicate that rare earth Y is an excellent modifier for A356 alloy. Y could not only refine primary a-Al phase, make the grain fine and equiaxed, reduce secondary dendrite arm spacing, but also could result in the transformation from striation texture to fibrous eutectic Si. When 0. 4wt% Y was added, the values of the tensile strength ab and elongation δ of A356 alloy reached 298 MPa and 9. 5%, which were increased by 29. 6% and 21.5% respectively, compared with the alloy without adding Y element.

关 键 词：A356铝合金 稀土元素 变质处理 显微组织 拉伸性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]