谐波和脉冲磁场在结晶器内的分布和对高纯铜凝固组织的影响  

Distribution of Harmonic and Pulsed Magnetic Field in Crystallizer and Their Effects on Solidification Structure of High Purity Cu

作　　者：宝磊 贾永辉 王翾 赵胤吉 乐启炽 罗俊峰 曾浩 BAO Lei;JIA Yong-hui;WANG Xuan;ZHAO Yin-ji;LE Qi-chi;LUO Jun-feng;ZENG Hao(Key Lab of Electromagnetic Processing of Materials,Ministry of Education,Northeastem University,Shenyang110819,Liaoning,China;Beijing Engineering Research Center of High Purity Metal Sputtring Target,Grikin Advanced Materlals Co.,Ltd,,Beijing 102200,China)

机构地区：[1]东北大学材料电磁过程研究教育部重点实验室,辽宁沈阳110819 [2]有研亿金新材料有限公司北京市高纯金属溅射靶材工程研究中心,北京102200

出　　处：《铸造》2020年第12期1284-1292,共9页Foundry

基　　金：国家重点研发计划(2017YFB0305504)。

摘　　要：通过模拟和试验手段研究了谐波和脉冲两种磁场的磁感强度和洛伦兹力在结晶器内部的分布特点及两种磁场对高纯铜熔体凝固行为和微观组织的影响规律及机理。结果表明,谐波磁场和脉冲磁场作用下,结晶器内最大磁感强度分别为0.065 T和0.084 T,最大洛伦兹力分别达到了170 000 N/m3和325 000 N/m3。谐波磁场所产生的洛伦兹力方向不断发生变化,虽然可使熔体产生强烈的横向振荡,但不利于熔体形成稳定的对流。相反,脉冲磁场可在短时间内产生极大的单方向洛伦兹力,使熔体产生较大加速度并促进熔体对流。总之,相比谐波磁场,脉冲磁场产生更高的磁感强度、更大的洛伦兹力和更深的作用区域,有效地提高了高纯铜凝固过程的热量传输并优化凝固行为,最终获得更均匀细小的微观组织。The distributions of magnetic flux density and Lorentz force of harmonic and pulsed magnetic fields in crystallizer, and the effects of the two magnetic fields on the solidification behavior and microstructure of high purity copper were studied by numerical simulation and experiment. The results show that under the action of harmonic magnetic field and pulsed magnetic field, the maximum magnetic flux density are 0.065 T and 0.084 T, and the maximum Lorentz force are 170 000 N/m^3 and 325 000 N/m^3, respectively. Although the harmonic magnetic field causes strong transverse oscillation because the direction of Lorentz force changes constantly, it is not conducive to the formation of stable convection. On the contrary, the pulsed magnetic field is capable to generate large unidirectional Lorentz force in a short time, which causes larger acceleration on the melt that is conducive to convection. Compared with the harmonic magnetic field, the pulsed magnetic field can produce higher magnetic flux density, larger Lorentz force and deeper action region that effectively improve the heat transfer and optimize the solidification behavior of high purity copper. Thereby, uniform and fine microstructure is finally obtained.

关 键 词：高纯铜 谐波磁场 脉冲磁场 半连续铸造 晶粒细化 

分 类 号：TG146.11[一般工业技术—材料科学与工程]