强脉冲磁场中Al-Cu共晶定向凝固组织的演变  

Evolvement of Al-Cu eutectic unidirectionally solidified morphology in high intensity pulsed magnetic field

作　　者：赵志龙[1] 张蓉[1] 刘林[1] 曾安培 

机构地区：[1]西北工业大学 [2]亚利桑那州立大学

出　　处：《材料研究学报》2005年第2期207-212,共6页Chinese Journal of Materials Research

基　　金：航空科学基金02H53065西北工业大学十五规划海外交流计划资助项目~~

摘　　要：脉冲磁场作用于Al-Cu共晶凝固的界面,研究了定向凝固组织的演变.随着脉冲磁场强度的提高,Al-Cu共晶定向凝固组织经历了由规则柱晶到破碎枝晶、粗化枝晶到重新规则化柱晶三个演化阶段; 在重新规则化柱晶试样中,共晶片层间距减小,晶团间富铜相析出明显.将感生电势场与溶质扩散场相耦合, 分析了脉冲磁场对凝固界面稳定性的影响,发现强脉冲磁场在金属熔体引起感生电势场效应,在凝固界面前沿诱发具有振荡特征的电致迁移,从而促进晶间扩散和减小成分过冷区域.The pulsed electric current produced by discharging of capacitors passed through the double solenoids with ferrosilicon core, and the instant strong pulsed magnetic field with the oscillating and declining characters was made between two ferrosilicon cores. The effect of high-pulsed magnetic field on the unidirectionally solidified AI-Cu eutectic microstructure with 10 μm/s drawn velocity was investigated. The AI-Cu eutectic solidified morphology experiences three evolution stages which are regular columnar structure to breaking off fine grain, coarsening dendrite to newly regularization columnar structure with increasing of charge energy. Rich copper phase evidently comes out of inter eutectic cells and the eutectic spacing decreases in newly regularization specimen. The stability of solidified interface is analyzed by coupling of induced electric potential field and solute diffusion field. The result showed that induced electric potential field caused by high pulsed magnetic field in metallic melt brought into oscillating solute electro-migration in front of solidifying interface, which has the effects of promoting solute diffusion inter-dendrite and reducing the constitutionally supercooling region.

关 键 词：金属材料 脉冲磁场 Al-Cu共晶 定向凝固 感生电势场 

分 类 号：TG113[金属学及工艺—物理冶金]