PRINCIPLE AND CONTROL OF NEW-STYLE PURIFICATION
EQUIPMENT OF 5N HIGH PURITY ALUMINUM

ZHANG Jiao¹  SUN Baode¹  HE Bo¹  MAO Hongyi²  CHEN Gang³   GE Aijing³

(1. Material Science and Engineering School, Shanghai Jiaotong University, Shanghai 200030;

2. Guizhou Branch Melting Plant, Aluminum Corporation of China Limited, Guiyang 550058;

3. Analysis & Testing Center, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050)

Abstract: Comparing with the old technique and equipments  of Al purification, combined with solidification characteristic of pure Al, a new-style purification furnace and corresponding technology is developed. Double induction coils heating mode is adopted and a higher and adjustable thermal gradient above solid and liquid interface is obtained. The growth velocity is controlled automatically by computer and the morphology of HPA crystal is stable cellular or single crystal. The results of concentration analysis show that, the purity of the ingots fabricated by this furnace can reach 99.999 3%, and there is a reasonable axial distribution of impurities.

Key words: Directional solidification  High purity aluminum  Purification equipment  Crystal

CLC No: TF804

国家863计划(2002AA336070)和上海市优秀学科带头人计划(03XD14009)资助项目. Received 20050509, received in revised form 20051004