Abstract:
Brazing of Ti600 to Ni-25%Si alloy was performed using Ti-Zr-Ni-Cu amorphous filler foil. The influence of brazing temperature on the microstructures and mechanical property of brazed joints have been studied and the strengthening mechanism of the Ti600/Ni-25%Si brazed joint was clarified. The results show that the brazing seam contains multiple reaction zones. With the increase of brazing temperature, the zone III comprised by (Ti,Zr)
2Si and Ti
2Ni disappears gradually while the zone IV with Ti
5Si
3 dispersing in Ti
2Ni gradually occupies the brazing seam. As the brazing temperature increases, the shear strength of brazed joints first augmented, reached the peak value of 177 MPa at 960 ℃ and then decreased. The dispersing Ti
5Si
3 phase distributing in the brittle Ti
2Ni phase, which hinders the crack propagation and strengthens the brittle Ti
2Ni, improves the shear strength of the brazed joint obtained at elevated temperature.