Seynergistic effect of Mo and Zr additions on microstructure and mechanical properties of Nb-Ti-Si-based alloys additively manufactured by laser directed energy deposition

作     者：Yunlong Li Xin Lin Yunlong Hu Jun Yu Junguo Zhao Hongbiao Dong Weidong Huang Yunlong Li;Xin Lin;Yunlong Hu;Jun Yu;Junguo Zhao;Hongbiao Dong;Weidong Huang

作者机构：State Key Laboratory of Solidification ProcessingNorthwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Metal High Performance Additive Manufacturing and Innovative DesignMIIT ChinaNorthwestern Polytechnical UniversityXi’an 710072China School of EngineeringUniversity of LeicesterLE17RHUK 

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

年 卷 期：2022年第103卷第8期

页      面：84-97页

核心收录：

学科分类：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）] 080502[工学-材料学] 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 National Key Research and Development Plan(Nos.2018YFB0704101,2016YFB1100104,2016YFB0700301) National Natural Science Foundation of China(Nos.51323008 and 51565041) the Fundamental Research Funds for the Central Universities(Nos.3102015BJ(II)ZS013 and 3102019QD0409) the Programme of Introducing Talents of Discipline to Universities,China(Grant No.B20028)。 

主　　题：alloys microstructure toughness 

摘      要：The synergistic effect of Mo and Zr additions on microstructure evolution,room-temperature fracture toughness and microhardness of Nb-22Ti-15Si-xMo-yZr(x=4,8,y=3,6)alloys manufactured by laser directed energy deposited(L-DED)have been investigated.The major phases in as-deposited 4Mo-3Zr alloy are Nb solid solution(Nbss),Nb_(3)Si andγ-Nb_(5)Si_(3).The Nb_(3)Si phases disappear with increasing Mo content to 8 at.%or increasing Zr content to 6%.γ-Nb_(5)Si_(3) precipitates formed in the Nbss of as-deposited xMo-yZr alloys due to the cyclic re-heating,and theγ-Nb_(5)Si_(3) precipitates and Nbss matrix exhibits orientation relationship(OR)of[001]Nbss//[1112]γand(110)Nbss//(0110)γin as-deposited 4Mo-6Zr alloy.The microstructure of xMo-yZr alloys became relative homogeneity and the Nbss matrix showed the better continuity after the heat treatment(1400°C/30 h).The Nb_(3)Si phase has transformed into Nbss andαNb_(5)Si_(3) with the OR have been determined as{100}Nbss//{100}αand{111}Nbss//{111}αin the heat-treated 4Mo-3Zr alloy.When Mo content increase to 8at.%,a part ofγ-Nb_(5)Si_(3) phase also transformed into theα-Nb_(5)Si_(3) phase with the OR have been determined as{1120}γ//{110}αand{1010}γ//{111}αafter heat treatment.Among the as-deposited alloys,the 4Mo-6Zr alloy has the highest fracture toughness KQ with the lowest hardness.The average KQ of 4Mo-6Zr and 8Mo-6Zr alloys increased by 28%and 30%after the heat treatment,and reached 13.61 and 11.43 MPa·m^(1/2),respectively.The hardness of Nb-22Ti-15Si-xMoyZr alloys is significantly decreased after the heat treatment.