交流电场对定向凝固及界面溶质分配系数的影响  

Effect of AC field on directional solidification and interface solute coefficient of distribution

作　　者：郭发军[1] 陆巧彤[1] 李玲珍[1] 宗燕兵[1] 苍大强[1] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083

出　　处：《北京科技大学学报》2006年第2期124-128,共5页Journal of University of Science and Technology Beijing

摘　　要：对交流电场作用下定向凝固组织的研究发现,交流电场对定向凝固组织有细化作用,且随电流的增大,其效果越明显,同时交流电场使凝固界面的溶质含量减小．通过对电场各种作用的分析发现：界面的化学势的减小使界面的稳定性增加；但界面能的增大、活度系数的减小以及界面溶质层内的震荡会使界面变薄,使界面的稳定性减小,从而破坏了胞晶的稳定生长,使柱状胞晶变成细碎的晶体．Directional solidification structure was studied under Alternating Current （AC） process. The result indicated that AC field had a refining effect on solidification structure, the effect became more obvious at a higher current, and AC field reduced the solute concentration at solidification interface. Analysis of all field effects showed that interface stability increased with the reduction of interface chemical potential, but interface layer attenuated and interface stability reduced in the situation of increased interface energy, small activity coefficient and oscillation at interface solute, accordingly the stability of cystiform crystals was restrained and columnar cystiform crystals turned refined ones.

关 键 词：交流电场 定向凝固组织 界面溶质含量 界面稳定性 晶粒细化 

分 类 号：TG142[一般工业技术—材料科学与工程] TN751[金属学及工艺—金属材料]