Microstructure evolution and grain refinement mechanism of rapidly solidified single-phase copper based alloys

作     者：Xiaolong Xu Cheng Tang Hongfu Wang Yukang An Yuhong Zhao Xiaolong Xu;Cheng Tang;Hongfu Wang;Yukang An;Yuhong Zhao

作者机构：College of Materials Science and EngineeringSchool of Mechanical EngineeringNorth University of ChinaTaiyuanShanxi 030051China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2022年第128卷第33期

页      面：160-179页

核心收录：

学科分类：0806[工学-冶金工程] 0817[工学-化学工程与技术] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0802[工学-机械工程] 0702[理学-物理学] 0801[工学-力学（可授工学、理学学位）] 

主　　题：Rapid solidification structure Grain refinement Dendrite remelting Recrystallization 

摘      要：The Cu65Ni35,Cu60Ni40 and Cu55Ni45 alloys were undercooled by fluxing method,and the rapid solidification structure with different undercoolings were also *** the same time,the interface migration process during rapid solidification was photographed by high-speed photography,and the relationship between the morphological characteristics of solidification front and undercooling was *** microstructures of the three alloys were observed by metallographic microscope,and the microstructure characteristics and evolution law were systematically *** was found that two grain refinement events occurred in the low undercooling range and high undercooling range,*** EBSD test of grain refined microstructures showed that the microstructure in the low undercooling range has a high proportion of low-angle grain boundaries and high strength ***,there were a large proportion of high-angle grain boundaries and a high proportion of twin grain boundaries and more randomly oriented grains in the microstructure in the high undercooling *** TEM test of the Cu55Ni45 alloy with the maximum undercooling of 284 K showed that there were high-density dislocation networks and stacking faults in the ***,the evolution relationship between microstructure hardness and undercooling was systematically *** was found that the microhardness of the three alloys decreased sharply near the critical *** with EBSD,TEM and microhardness analysis,it was confirmed that the grain refinement under low undercooling was caused by dendrite remelting,while the grain refinement under high undercooling was caused by stress-induced recrystallization.