【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．更多还原

【Abstract】 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 re- strained and columnar cystiform crystals turned refined ones.更多还原