玻璃净化剂组分对Cu₅₀Ni₅₀合金熔体过冷度稳定性的影响①

来源期刊：中国有色金属学报2000年第1期

论文作者：郭学锋 杨根仓

文章页码：77 - 80

关键词：玻璃净化剂; Cu-Ni合金;深过冷;物理净化;化学净化

Key words：glass denucleating agent; Cu-Ni alloy melts; high undercooling; physical purification; physicochemical purification

摘    要：在高真空下,研究了净化剂B₂O₃, 79%SiO₂+12.5% B₂O₃+2.2%Al₂O₃+0.6%CaO+5.7%Na₂O(简写为Na-Ca-Al-B-Si)和50%Na-Ca-Al-B-Si+50%Na₂B₇O₄对Cu₅₀Ni₅₀合金熔体在循环过热过程中的过冷度及其稳定性的影响。结果表明, B₂O₃的净化过程为纯物理净化,合金熔体在循环过热过程中不能获得稳定的深过冷; Na-Ca-Al-B-Si玻璃的净化过程为物理-化学复合净化,但由于该净化剂粘度大,在循环过热的冷却过程中因发生合金熔体与净化剂分离,使合金熔体表面氧化,导致合金熔体同样不能获得稳定深过冷; 50%Na-Ca-Al-B-Si+50%Na₂B₇O₄玻璃的净化过程为物理-化学复合净化,该净化剂粘度适中,合金熔体在循环过热过程中可以获得稳定深过冷。

Abstract: The undercooling and its stability of Cu₅₀Ni₅₀ alloy melts were investigated in vacuo using different glass slags, B₂O₃, 79% SiO₂+12.5B₂O₃+2.2 %Al₂O₃+0.6% CaO+5.7%Na₂O(simplified as Na-Ca-Al-B-Si), and 50% Na-Ca-Al-B-Si+50%Na₂B₇O₄. The results showed that different glass slag has different denucleating mechanism. The purification of B₂O₃ glass is only a physical process. The alloy melts can not obtain stable undercooling during superheating-cooling cycle. Taking 79%SiO₂+12.5% B₂O₃+2.2%Al₂O₃+0.6% CaO+5.7%Na₂O as purifying agent, the denucleating mechanism is a comprehensively physicochemical process. Yet the stability of undercooling is still low because of the separation between melt and glass occurred during cooling process of superheating-cooling cycle. Stable undercooling can be obtained by physicochemical denucleating processes of 50%Na-Ca-Al-B-Si+50%Na₂B₇O₄ molten glass because of its appropriate viscosity.