凝固冷却速度对短纤维增强铝合金复合材料基体成分偏析的影响  

Effect of Cooling Rate on Solidification Microsegregation of Fiber Reinforced Aluminum Alloy Composite

作　　者：靖青秀[1] 刘政[1] 

机构地区：[1]南方冶金学院材料与化学工程学院,江西赣州341000

出　　处：《热加工工艺》2004年第3期3-5,共3页Hot Working Technology

基　　金：国家教育部科学技术研究重点项目(00191);江西省自然科学基金项目(0150032)

摘　　要：采用挤压铸造法制备Al2O3f/Al-4.5Cu复合材料,研究了凝固冷却速度对复合材料基体成分偏析的影响。结果表明:Al-4.5Cu合金基体初晶在纤维间隙中生核长大,纤维不能作为基体α初晶非自发形核衬底;复合材料基体中存在由纤维间隙中心至纤维/基体界面或晶界处渐增的Cu浓度梯度,纤维周围存在共晶第二相偏析;凝固冷却速度的增大使基体偏析加剧。The short fiber Al_2O_3 reinforced Al-4.5Cu composites were made by squeeze casting.The effect of cooling rate on matrix microsegregation in composites was studied and measured quantitatively.The results show that the primary crystal of Al-4.5Cu alloy matrix nucleates and grows in the interstice between fibers.The fiber surface can not serve as site for heterogeneous nucleation of the α primary dendrite.It exists that the increasing copper concentration gradient from the center of the interstice between fibers to the interface or the grain boundaries.There are the eutectic phases around the fibers.The concentration segregation in the matrix is increased with cooling rate rising.

关 键 词：短纤维 铝合金 复合材料 凝固 显微偏析 

分 类 号：TG331[金属学及工艺—金属压力加工]