Microstructures and mechanical properties of Ti3Al/Ni-based superalloy joints brazed with AuNi filler metal

作     者：H.S. Ren H.P.Xiong W.M. Long B. Chen Y.X. Shen J. Pang 

作者机构：Welding and Plastic Forming DivisionBeijing Institutes of Aeronautical MatericalBeijing 100095China State Key Laboratory of Advanced Brazing Filler Metals and TechnologyZhengzhou Research Institute of Mechanical EngineeringZhengzhou 450001 China Department of Material Science and EngineeringBeihang UniversityBeijing 100191China 

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

年 卷 期：2019年第35卷第9期

页      面：2070-2078页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：sponsored by the National Natural Science Foundation of China (No. 51705489) the State Key Laboratory of Advanced Brazing Filler Metals and Technology, Zhengzhou Research Institute of Mechanical Engineering (No. SKLABFMT201603) 

主　　题：Ti3Al-based alloy Ni-based superalloy Brazing Microstructure Tensile strength 

摘      要：For the purpose of high-temperature service and the weight reduction in aviation engineering applications, the dissimilar joining of Ti3Al-based alloy to Ni-based superalloy (GH536) was conducted using Au-17.5Ni (wt%) brazing filler metal. The microstructure and chemical composition at the interfaces were investigated by scanning electron microscope, X-ray diffraction and transmission electron microscope. The diffusion behaviors of elements were analyzed as well. The results indicated that the Ti3Al/GH536 joint microstructure was characterized by multiple layer structures. Element Ni from Au-Ni filler metal reacted with Ti3Al base metal, leading to the formation of AlNi2Ti and NiTi compounds. Element Ni from Ti3Al base metal reacted with Ni and thus Ni3Nb phase was detected in the joint central area. Due to the dissolution of Ni-based superalloy,(Ni,Au) solid solution ((Ni,Au)ss) and Ni-rich phase were visible adjacent to the superalloy side. The average tensile strength of all the joints brazed at 1253 K for 5-20 min was above 356 MPa at room-temperature. In particular, the joints brazed at 1253 K/15 min presented the maximum tensile strength of434 MPa at room-temperature, and the strength of 314 MPa was maintained at 923 K. AlNi2Ti compound resulted in the highest hardness area and the fracture of the samples subjected to the tensile test mainly occurred in this zone.