GRAIN REFINEMENT IN BULK UNDERCOOLED Ni-BASED ALLOY

来源期刊：中国有色金属学报(英文版)1993年第4期

论文作者：Li Delin Yang Gencang Zhou Yaohe

文章页码：66 - 71

Key words：Ni-based alloy; high undercooling; recalescence; grain refinement

Abstract: Fluxing of 5 g bulk melt Ni77Si13B10 permits high undercoolings to be attained prior to nu- cleation onset.Investigations of grain refinement in the bulk undercooled alloy as a function of undercooling,recalescence behavior and cooling rate have been reported.A significant inhomo- geneity of reduction in grain size of a bulk sample is observed,which is caused by the different so- lidification conditions:(1)recalescence process,and(2)the followed plateau in which the heat release and extraction rates are equal.It is concluded that the homogeneous refined microstructure can be achieved if the initial undercooling prior to nucleation,or cooling rate after recalescence is further increased.