Undercooling heredity of Cu₇₀Ni₃₀ melt solidified in non-catalytic nucleation coated mould

来源期刊：中国有色金属学报(英文版)2000年第4期

论文作者：郭学锋 刘勇长 杨根仓 邢建东

文章页码：481 - 484

Key words：Cu₇₀Ni₃₀alloy; non-catalytic nucleation coating; undercooling heredity

Abstract: A new concept of undercooling heredity is developed to evaluate the undercooling ability in a non-catalytic nucleation coated mould, where alloy melts were highly undercooled previously. Before the heredity experiment a noncatalytic nucleation composite glass-lined coating (B-F) was prepared on the inner surface of mould and the Cu₇₀Ni₃₀alloy was selected to perform undercooling experiment in the B-F non-catalytic coating mould. Its ratio of undercooling heredity was 0.76. The results prove that the B-F coating is an ideal non-catalytic media for purified Cu₇₀Ni₃₀alloy melts due to its small contact angle between the melt and coating layer. Considering that various microstructures form under different undercoolings, two critical undercoolings,ΔT₁andΔT₂, and their corresponding microstructures of Cu₇₀Ni₃₀alloy are well defined. Moreover, it is found that the manned-trigging solidification in the non-catalytic coating mould could be used to get directional undercooling dendrite structure while the melt undercooling is larger than the critical undercoolingΔT₂.