Interfacial microstructure and mechanical properties of K417G superalloy brazed with BNi-5 brazing filler metal

K417G nickel-based superalloy has excellent high-temperature mechanical properties and can be applied in the manufacturing of hot end components of aircraft engines. Brazed joints of K417G alloy were studied by BNi-5 nickel-based brazing filler metal. Effects of different holding time on microstructure evolution and high-temperature mechanical properties of brazed joints were analyzed. At 1160 ℃ for 15 mins, phases at interface of K417G alloy brazed joints were mainly composed of γ + γ' phase, Ti-rich carbide phase and (Ni,Cr)₃Si phase. With the further extension of holding time, interfacial reaction and element diffusion became more sufficient. Meanwhile, distribution of silicide phase in brazed joints showed a dispersion trend, and phase size was refined. At 1 160 ℃ for 30 mins, average tensile strength of brazed joints at 950 ℃ was 412 MPa.