Recalescence Behavior, Solidification Characteristics and Microstructure Transformation of Rapidly Solidified Undercooled Cu-based Alloys  

作　　者：WANG Hongfu TANG Cheng HE Xibin YANG Jin’e XIE Jinpeng 王洪福;TANG Cheng;HE Xibin;YANG Jin’e;XIE Jinpeng(School of Mechanical Engineering,North University of China,Taiyuan 030051,China;Jiangsu Yingchuang Power Technology Co.,Ltd,Suzhou 215000,China)

机构地区：[1]School of Mechanical Engineering,North University of China,Taiyuan 030051,China [2]Jiangsu Yingchuang Power Technology Co.,Ltd,Suzhou 215000,China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2022年第6期1228-1239,共12页武汉理工大学学报（材料科学英文版）

基　　金：by the Basic Research Projects in Shanxi Province(Nos.201801D221151 and 202103021224183)。

摘　　要：The undercooled solidification microstructures of Cu55Ni45,Cu55Ni43Co2,and Cu60Ni38Co2 Cu-base alloys were obtained by fluxing method.Using infrared temperature measuring device,the law of the change of the recalescence degree with the increase of the undercooling during rapid solidification was studied.At the same time,high-speed camera was used to capture and photograph the images of solid/liquid interface migration during rapid solidification of undercooled melt,and the morphology evolution of solidification front was discussed.Finally,the microstructure morphology and transformation process of the Cubased alloys were systematically analyzed.It is found that the microstructure morphology of the alloys goes through the same evolution process and appeared two grain refinement phenomena,that is,“coarse dendrite-equiaxed grain-oriented fine dendrite-equiaxed grain”.But its characteristics undercoolingΔT_(1),ΔT_(2),and critical undercoolingΔT^(*)varies.Electron backscatter diffraction(EBSD)and transmission electron microscopy(TEM)were used to characterize the grain refinement structure with high undercooling.EBSD results show that the grain refinement structure with high undercooling presents a very high proportion of high angle grain boundaries,the grain orientation is random and there is no high strength texture,and a large number of annealing twins,which indicates that recrystallization occurs in the structure.TEM results show that dislocation network and stacking fault density are relatively low in most areas of grain refinement structure with high undercooling,which can confirm the theory that stress induces recrystallization of the structure.

关 键 词：rapid solidification recalescence degree solidification front MICROSTRUCTURE 

分 类 号：TG146.11[一般工业技术—材料科学与工程]