Microstructure and shear strength of γ-TiAl/GH536 joints brazed with Ti-Zr-Cu-Ni-Fe-Co-Mo filler alloy

作者：Li, Li; Zhao, Wei; Feng, Zhi-xue; Sun, Jia; Li, Xiao-qiang^*

来源：TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA, 2020, 30(8): 2143-2155.

DOI：10.1016/S1003-6326(20)65367-5

• gamma-TiAl alloy
• Ni-based superalloy
• vacuum brazing
• amorphous filler
• microstructure
• shear strength

The influence of brazing temperature and brazing time on the microstructure and shear strength of gamma-TiAl/GH536 joints brazed with Ti-Zr-Cu-Ni-Fe-Co-Mo filler was investigated using SEM, EDS, XRD and universal testing machine. Results show that all the brazed joints mainly consist of four reaction layers regardless of the brazing temperature and brazing time. The thickness of the brazed seam and the average shear strength of the joint increase firstly and then decrease with brazing temperature in the range of 1090-1170 degrees C and brazing time varying from 0 to 20 min. The maximum shear strength of 262 MPa is obtained at 1150 degrees C for 10 min. The brittle Al3NiTi2 and TiNi3 intermetallics are the main controlling factors for the crack generation and deterioration of joint strength. The fracture surface is characterized as typical cleavage fracture and it mainly consists of massive brittle Al3NiTi2 intermetallics.