Principle and in-situ observation on discrete solidification  

作　　者：Xiaoping Ma Dianzhong Li Zhuo Zhao Hongwei Liu Yanfei Cao Paixian Fu Pei Wang 

机构地区：[1]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]Department of Materials Science and Engineering,University of Science and Technology Liaoning,Anshan 114051,China

出　　处：《Journal of Materials Science & Technology》2024年第25期28-41,共14页材料科学技术(英文版)

基　　金：supported by the General Program of the National Natural Science Foundation of China(Grant No.52271041);the Key Program of the National Natural Science Foundation of China(Grant No.52031013).

摘　　要：Solidification is an important branch of material science.By model calculation and in-situ observation in this work,distinct from traditional solidification of continuous solid growth,the evolution of discrete so-lidification was investigated,and a new principle for discrete solidification is established based on segre-gation evolution in a semi-solid matrix.The solidification evolution of Al-2 wt.%Cu alloy was investigated by model calculation under different initial undercooling and cooling rates,under superimposed multi-scale temperature fluctuations,and under variable temperature fluctuations.The initiation and propa-gation of segregation fluctuations in semi-solid matrix were verified within a traditional dendritic arm.The alternate solid elements evolved from semi-solid matrix act as periodic dams inhibiting serious seg-regation.Based on the new solidification principle,a multi-scale dendritic pattern was reproduced in a two-dimensional calculation.The new solidification principle reveals the essence of multi-scale mi-crostructures as multi-scale segregation patterns and highlights the feasibility of controlling multi-scale microstructures and segregations.

关 键 词：Solidification principle DENDRITE SEGREGATION Semi-solid matrix 

分 类 号：TG1[金属学及工艺—金属学]