Rapid growth of primary dendrite in highly undercooled copper-antimany alloy  

作　　者：YAO Wenjing , CAO Chongde and WEI Bingbo(Laboratory of Materials Science in Space, Department of Applied Physics, Northwestern Polytechnical University, Xi’an 710072, China) 

出　　处：《Progress in Natural Science:Materials International》2002年第12期935-939,共5页自然科学进展·国际材料（英文版）

基　　金：the National Natural Science Foundation of China (Grant Nos. 50221101 and 50101010) ; Fok Ying Tung Education Foundation (Grant No. 71044).

摘　　要：The droplets of Cu-11wt.%Sb hypoeutectic alloy have been rapidly solidified during containerless processing in a 3 m drop tube. The undercooling and cooling rates are estimated, and both play a dominant role in the dendritic growth of primary Cu phase. Undercoolings up to 200 K (0.16TL, where TL is the liquidus temperature) have been obtained in the experiment. With the increase of undercooling, the microstructural evolution of primary Cu phase proceeds from remelted dendrites to the equiaxed grains. A coarse dendritic grain microstructure can form in the undercooling range of 61～102 K and at cooling rates of 1.35×102～2.66×103 K/s. The segregationless solidification of Cu-11wt.%Sb hypoeutectic alloy occurs when undercooling is more than 176 K. The growth of primary Cu phase is mainly controlled by solute diffusion.The droplets of Cu-11wt. % Sb hypoeutectic alloy have been rapidly solidified during containerless processing in a 3 m drop tube. The undercooling and cooling rates are estimated, and both play a dominant role in the dendritic growth of primary Cu phase. Undercoolings up to 200 K (0.16 T-L, where T-L is the liquidus temperature) have been obtained in the experiment. With the increase of undercooling, the microstructural. evolution of primary Cu phase proceeds from remelted dendrites to the equiaxed grains. A coarse dendritic, grain microstructure can form in the undercooling range of 61similar to102 K and at cooling rates of 1.35 x 10(2)similar to2.66 x 10(3) K/s. The segregationless solidification of Cu-11wt. % Sb hypoeutectic alloy occurs when undercooling is more than 176 K. The growth of primary Cu phase is mainly controlled by solute diffusion.

关 键 词：rapid growth  undercooling  copper  dendrite  DROP tube. 

分 类 号：TG111.7[金属学及工艺—物理冶金]