Fabrication and analysis of TIG welding-brazing butt joints of in-situ TiB2/7050 composite and TA2

作     者：Huan-huan Sun Yi-bo Ren Yang Feng Hao-qiang Ba Dong Chen Chun-juan Xia Hao-wei Wang Huan-huan Sun;Yi-bo Ren;Yang Feng;Hao-qiang Ba;Dong Chen;Chun-juan Xia;Hao-wei Wang

作者机构：School of Materials Science&EngineeringShenyang Ligong UniversityShenyangChina School of Materials Science&EngineeringShanghai Jiao Tong UniversityShanghaiChina 

出 版 物：《Defence Technology（防务技术）》 (Defence Technology)

年 卷 期：2021年第17卷第3期

页      面：1062-1070页

核心收录：

学科分类：08[工学] 0826[工学-兵器科学与技术] 

基　　金：supported by Basic Science Research Project of Colleges and Universities in Liaoning Province in China (No. LG201714) 

主　　题：In-situ TiB2/7050 composite TA2 TIG welding-brazing Fabrication Analysis 

摘      要：Lightweight hybrid structures of Al MMCs and titanium alloy dissimilar materials have great prospect in the defence industry application. So, it is necessary to join Al MMCs with Ti metal to achieve this structural design. In this work, in-situ Ti B_(2)/7050 composite and TA2 were firstly attempted to join by TIG welding-brazing technique. The result was that the intact welding-brazing butt joint was successfully fabricated. The joint presents dual characteristics, being a brazing on TA2 side and a welding on Ti B_(2)/7050 side. At brazing joint side, ER4043 filler metal effectively wets on TA2 under TIG heating condition,and a continuous interfacial reaction layer with 1 e3 mm is formed at welded metal/TA2 interface. The whole interfacial reaction layers are composed of Ti(Al Si)3 intermetallic compounds(IMCs), but their morphologies at the different regions present obvious distinguishes. The microhardness of the reaction layers is as much as 141 e190 HV. At welding joints side, the fusion zone appears the equixaed crystal structure, and the grain sizes are much smaller than those of welded metal, which is attributed to the effect of Ti B2 particulates from the melted Ti B_(2)/7050 on acceleration formation and inhibiting growth for the new crystal nucleus. The tensile test results show that average tensile strength of the optimal welding-brazing joint is able to achieve 138 MPa. The failure of the tensile joint occurs by quasi-cleavage pattern, and the cracks initiate from the IMCs layer at the groove surface of TA2 and propagate into the welded metal.