Segregation of solute atoms in ZrC grain boundaries and their effects on grain boundary strengths

作     者：Fu-Zhi Dai Yinjie Sun Yixiao Ren Huimin Xiang Yanchun Zhou Fu-Zhi Dai;Yinjie Sun;Yixiao Ren;Huimin Xiang;Yanchun Zhou

作者机构：Science and Technology on Advanced Functional Composite LaboratoryAerospace Research Institute of Materials&Processing TechnologyBeijing 100076China 

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

年 卷 期：2022年第101卷第6期

页      面：234-241页

核心收录：

学科分类：080503[工学-材料加工工程] 08[工学] 0817[工学-化学工程与技术] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China under Grant No.51972089。 

主　　题：ZrC Grain boundary Segregation Strength First-principles calculation Machine learning 

摘      要：ZrC is a promising candidate for the application in ultra-high temperature regime due to its unique combination of excellent properties,such as high melting point,good chemical inertness and high temperature stability.The rapid decrease of strength at high temperatures,however,is one of the obstacles that impedes its practical services.Strengthening of grain boundaries by solute segregation is believed to be an effective way to improve its high temperature performance.Therefore,the segregation tendency of ten solid solute atoms,including Sc,Ti,V,Cr,Y,Nb,Mo,Hf,Ta,W,in Zr C grain boundaries,and the strengthening/weakening effects on grain boundaries due to segregation are investigated by first-principles calculations.The segregation tendency is found dominated by the size effect,which is confirmed by both a qualitative analysis and a quantitative approach based on support vector regression.It means that big atoms tend to segregate to grain boundary sites with local expansions,while small atoms tend to segregate to grain boundary sites with local compressions.Simulations on stress-strain responses indicate that segregation of small atoms(Ti,V,Cr,Nb,Ta,Mo,W)can usually improve grain boundary strengths by inducing compression strains to grain boundaries,even though there is also an exception.In contrast,segregation of Sc and Y will soften grain boundaries.The results reveal that strengthening of grain boundaries by solute segregation is a valuable avenue to enhance high temperature mechanical properties of ZrC,providing guidelines for further design of ZrC based materials.