Formation mechanism of interfacial microstructures and mechanical properties of Ti2AlNb/Ni-based superalloy joints brazed with NiCrFeSiB filler metal

Progress in Natural Science: Materials International

Shujie Pang¹  Weimin Long²  Huaping Xiong³  Haishui Ren³  Bo Chen³  Xinyu Ren³ 

[1] Department of Material Science and Engineering, Beihang University, Beijing, 100191, China;State Key Laboratory of Advanced Brazing Filler Metals and Technology, Zhengzhou Research Institute of Mechanical Engineering, Zhengzhou, 450001, China;Welding and Plastic Forming Division, Beijing Institute of Aeronautical Materials, Beijing, 100095, China;

关键词: Ti2AlNb alloy;    Ni-based superally;    Brazing;    Microstructure;    Mechanical properties;   

DOI  :  

来源: DOAJ

【 摘 要 】

Dissimilar brazing of Ti2AlNb-based alloy and Ni-based wrought superalloy (GH536) was studied using NiCrFeSiB filler metal. The Ti2AlNb/GH536 joints were analyzed by scanning electron microscope (SEM) equipped with an electron probe micro-analyzer (EPMA), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The formation mechanism of interfacial microstructure and mechanical properties of Ti2AlNb/GH536 joints were studied. The results indicated that Ti2Ni(Al,Nb), AlNi2Ti and TiB2 reaction layers were formed in the joint adjacent to Ti2AlNb base metal. These layers resulted in high micro-hardness and the weak link of the joint. γ solid solution was formed through isothermal solidification and β1-Ni3Si phase precipitated in the γ solid solution during cooling process. Ni3B, β1-Ni3Si and CrB phases appeared in the centre of the joint. Blocky and needle-like borides formed within the diffusion affected zone of GH536 base alloy. The maximum tensile strength of Ti2AlNb/GH536 joints reached 425 ​MPa ​at room temperature and the strength value of 373 ​MPa was maintained at 923 ​K.

【 授权许可】

Unknown