Study of ultrahigh-purity copper billets refined by vacuum melting and directional solidification

作     者：FU Yabo CHEN Jie LIU Ning LU Yiping LI Tingju YIN Guomao 

作者机构：Key Laboratory of Materials Modification by Laser Ion and Electron Beams Ministry of Education Dalian University of Technology Dalian 116085 China School of Materials Science and Engineering Dalian University of Technology Dalian 116085 China 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2011年第30卷第3期

页      面：304-309页

核心收录：

学科分类：08[工学] 0806[工学-冶金工程] 080601[工学-冶金物理化学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

主　　题：copper refining vacuum melting directional solidification electrical conductivity 

摘      要：The purpose of this paper is to study large-sized copper billets refined with 5N ultrahigh purity after vacuum melting and directional solidifi-cation （VMDS）. The precise impurity analysis of copper billets was carried out with a glow discharge mass spectrometer （GDMS）. The re-sults demonstrate that the total concentration of twenty-two impurities is decreased by 63.1wt.%-66.5 wt.%. Ag, P, S, Na, Mg, Se, Zn, In and Bi are easy to be removed due to lgPimp - lgPCu 1.5, and they can be removed effectively under the vacuum condition of 1650-1700 K for 30 min. The electrical conductivity of 5N copper is higher than that of the raw material as the impurity concentrations decrease. The segrega-tion effect in directional solidification can be remarkable when the equilibrium distribution coefficient （k0） value is less than 0.65 due to the strong affinity of Cu for some metallic and non-metallic impurities.