Abstract: Polycrystalline ZrO₂-3 mol.%Y₂O₃ was brazed to Ti-6Al-4V by using a Ti₄₇Zr₂₈Cu₁₄Ni₁₁(at.%) amorphous ribbon at 1123-1273 K in a high vacuum. The influences of brazing temperature on the microstructure and shear strength of the joints were investigated. The interfacial microstructures can be described as ZrO₂/TiO+TiO₂+Cu₂Ti₄O+Ni₂Ti₄O/α-Ti+(Ti,Zr)₂(Cu,Ni) eutectic/acicular WidmanstÄaten structure/Ti-6Al-4V alloy. With the increase in the brazing temperature, the thickness of the TiO+TiO₂+Cu₂Ti₄O+Ni₂Ti₄O layer reduced, the content of the α-Ti+(Ti,Zr)2(Cu,Ni) eutectic phase decreased, while that of the coarse α-Ti phase gradually increased. The shear strength of the joints did not show a close relationship with the thickness of the  TiO+TiO₂+Cu₂Ti₄O+Ni₂Ti₄O layer. However, when the coarse (Ti,Zr)₂(Cu,Ni) phase was non-uniformly distributed in the α-Ti phase, or when α-Ti solely situated at the center of the joint, forming a coarse block or even connecting into a continuous strip, the shear strength greatly decreased.

Key words: Brazing, Amorphous filler, Interface, Microstructure, Shear strength