Abstract:
A high-entropy amorphous brazing filler metal (TiZrHf)
40(NiCu)
55Al
5 was designed for vacuum brazing of Ti
2AlNb alloy and GH4169 nickel-based superalloy. The effects of brazing parameters on the interfacial microstructure, mechanical properties and fracture behavior of Ti
2AlNb alloy/GH4169 nickel-based superalloy brazed joints were studied. The results showed that the brazed joints can be divided into Ti
2AlNb/ diffusion reaction zone (zone I)/brazing seam center zone (zone II)/diffusion reaction zone (zone III)/GH4169. The typical interface microstructure of brazed joints was Ti
2AlNb/B2 + Ti
2Ni(Al, Nb)/(Ti, Zr, Hf)(Ni, Cu)/(Ni, Cr, Fe, Ti)
ss + Cr-rich (Ni, Cr, Fe)
ss + Ni-rich(Ni, Cr, Fe)ss + (Ni, Cr, Fe)
ss/GH4169.With the increase of brazing temperature and brazing time, the shear strength of brazed joints increased first and then decreased. When the brazing temperature was
1020 ℃ and the brazing time was 15 min, the maximum shear strength of 237 MPa was obtained. The fracture analysis showed that the joint was mainly broken at zone of Ti
2Ni(Al, Nb) + (Ti, Zr, Hf) (Ni, Cu) + (Ni, Cr, Fe, Ti)
ss, and fracture path gradually expanded to the diffusion reaction zone. The fracture morphology showed typical cleavage fracture characteristics.