GRAIN REFINEMENT IN BULK UNDERCOOLED Ni-BASED ALLOY  

作　　者：Li,Delin Yang,Gencang Zhou,Yaohe Northwestern Polytechnical University,Xi’an 710072,China 

出　　处：《中国有色金属学会会刊：英文版》1993年第4期66-71,共6页Transactions of Nonferrous Metals Society of China

基　　金：Financilly suported by the National Natural Science Foundation of China

摘　　要：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 ofundercooling,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 heatrelease and extraction rates are equal.It is concluded that the homogeneous refined microstructurecan be achieved if the initial undercooling prior to nucleation,or cooling rate after recalescence isfurther increased.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.

关 键 词：NI-BASED alloy high UNDERCOOLING RECALESCENCE grain REFINEMENT 

分 类 号：TG146[一般工业技术—材料科学与工程]