鋁合金表面脈沖電磁場對半連續鑄造晶粒的細化

白慶偉; 麻永林; 邢淑清; 馮艷飛; 鮑鑫宇; 于文霞

doi:10.13374/j.issn2095-9389.2017.12.008

鋁合金表面脈沖電磁場對半連續鑄造晶粒的細化

doi: 10.13374/j.issn2095-9389.2017.12.008

內蒙古科技大學材料與冶金學院, 包頭 014010

基金項目:

國家自然科學基金資助項目（51044002）；科技部國際合作資助項目（2010DFB70630）

詳細信息

中圖分類號: TF821
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出版歷程
- 收稿日期: 2017-05-03

Refining of a DC-casting aluminum alloy structure using surface electromagnetic pulsing

School of Material and Metallurgy, Inner Mongolia University of Science & Technology, Baotou 014010, China

摘要

摘要: 采用一種新型熔體表面脈沖電磁技術對7A04鋁合金半連續鑄造凝固組織細化處理，分析脈沖電磁場對凝固組織及性能的影響.引入勢能的觀點，探討脈沖磁能作用下的晶體形核動力學及初生晶核運動形式.結果表明，經表面脈沖電磁場處理后，凝固組織由晶粒尺寸粗大的玫瑰結構轉變為細小且圓整的球狀結構，鑄錠心部及邊部晶粒尺寸分別下降22.7%和14.2%，強度、塑性均有提高.動力學分析認為，脈沖電磁能降低體系形核所需的臨界吉布斯自由能是增加形核率的重要原因，同時可導致初生α-Al運動的勢能增加，促使初生α-Al顆粒優先到達穩定位置.
- 晶粒細化 /
- 脈沖電磁場 /
- 形核率 /
- 磁勢能
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 indicate 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 appears to increase potential energy of the primary α-Al, which quickly attains a steady state in the melt.
- grain refinement /
- pulse electromagnetic field /
- nucleation rate /
- magnetic potential energy

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參考文獻(23)

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