Abstract:
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.