工程科学学报2017，Vol.39Issue(12)：1828-1834,7.DOI:10.13374/j.issn2095-9389.2017.12.008
铝合金表面脉冲电磁场对半连续铸造晶粒的细化
Refining of a DC-casting aluminum alloy structure using surface electromagnetic pulsing
摘要
Abstract
A new technique termed surface electromagnetic pulse refining was developed for improving the solidified structure of a 7A04 aluminum alloy DC-casting. The effect of the pulsed electromagnetic field on the solidified microstructure and properties of the alloy was investigated. From the viewpoint of potential energy, the dynamics of forming nucleus and the grain motion were theoretically predicted based on the concepts of the action of the pulsed electromagnetic energy on the melt or particles. The experimental results in-dicate that the solidified structures are modified by the electromagnetic pulse from rose-like structures to globular structures with a fine grain size. The grain size in the edge zone and central zone of the billet is decreased by 22. 7% and 14. 2%, respectively, and the strength and plasticity of the alloy are also increased. The grain refinement can be explained by the nucleation rate increases, because the electromagnetic energy helps to decrease the critical Gibbs free energy of the system. In addition, the electromagnetic pulse ap-pears to increase potential energy of the primary α-Al, which quickly attains a steady state in the melt.关键词
晶粒细化/脉冲电磁场/形核率/磁势能Key words
grain refinement/pulse electromagnetic field/nucleation rate/magnetic potential energy分类
矿业与冶金引用本文复制引用
白庆伟,麻永林,邢淑清,冯艳飞,鲍鑫宇,于文霞..铝合金表面脉冲电磁场对半连续铸造晶粒的细化[J].工程科学学报,2017,39(12):1828-1834,7.基金项目
国家自然科学基金资助项目(51044002) （51044002）
科技部国际合作资助项目(2010DFB70630) （2010DFB70630）
