Solidification Behavior of Immiscible Alloys under the Effect of a Direct Current  

作　　者：Hongxiang Jiang Jiuzhou Zhao Jie He 

机构地区：[1]Institute of Metal Research,Chinese Academy of Sciences

出　　处：《Journal of Materials Science & Technology》2014年第10期1027-1035,共9页材料科学技术（英文版）

基　　金：the financial support from the National Natural Science Foundation of China(Nos. 51071159,51031003,51271185 and u0837601)

摘　　要：Directional solidification experiments were carried out with Al-Pb alloys under the effect of a direct current （DC）. The experimental results show that the DC causes a migration of the minority phase droplets （MPDs） from the middle part to the surface region of the sample, Samples with either a finely dispersed microstructure or a shell/ core structure were obtained by solidifying the alloy under the effect of the properly selected DC densities, A model was developed to describe the microstructure evolution in an immiscible alloy directionaliy solidified under the effect of the DC. The microstructure formation in the AI-Pb alloys was calculated. The numerical results are in favorable agreement with the experimental ones. They demonstrate that the DC affects the microstructure formation mainly through changing the spatial motions of the MPDs and the temperature field of the melt in front of the solid/liquid interface. The formation mechanisms of the finely dispersed microstructure as well as the shell/core structure were sufficiently clarified.Directional solidification experiments were carried out with Al-Pb alloys under the effect of a direct current （DC）. The experimental results show that the DC causes a migration of the minority phase droplets （MPDs） from the middle part to the surface region of the sample, Samples with either a finely dispersed microstructure or a shell/ core structure were obtained by solidifying the alloy under the effect of the properly selected DC densities, A model was developed to describe the microstructure evolution in an immiscible alloy directionaliy solidified under the effect of the DC. The microstructure formation in the AI-Pb alloys was calculated. The numerical results are in favorable agreement with the experimental ones. They demonstrate that the DC affects the microstructure formation mainly through changing the spatial motions of the MPDs and the temperature field of the melt in front of the solid/liquid interface. The formation mechanisms of the finely dispersed microstructure as well as the shell/core structure were sufficiently clarified.

关 键 词：Rapid directional solidification Direct current Finely dispersed microstructure Shell/core structure 

分 类 号：TG111.4[金属学及工艺—物理冶金] TG146.21[金属学及工艺—金属学]