Effects of Fabrication Parameters on Interface of Zirconia and Ti-6Al-4V Joints Using Zr₅₅Cu₃₀Al₁₀Ni₅ Amorphous Filler

ZrO₂ was brazed to Ti-6Al-4V using a Zr₅₅Cu₃₀Al₁₀Ni₅ (at.%) amorphous filler in a high vacuum at 1173-1273 K. The influences of brazing temperature, holding time, and cooling rate on the microstructure and shear strength of the joints were investigated. The interfacial microstructures can be characterized as ZrO₂/ZrO_2−x  + TiO/(Zr,Ti)₂(Cu,Ni)/(Zr,Ti)₂(Cu,Ni,Al)/acicular Widmanstäten structure/Ti-6Al-4V. With the increase in the brazing temperature, both the thickness of the ZrO_2−x  + TiO layer and the content of the (Zr,Ti)₂(Cu,Ni) phase decreased. However, the acicular Widmanstäten structure gradually increased. With the increase in the holding time, the (Zr,Ti)₂(Cu,Ni) phase decreased, and the thickness of the (Zr,Ti)₂(Cu,Ni) + (Zr,Ti)₂(Cu,Ni,Al) layer decreased. In addition, cracks formed adjacent to the ZrO₂ side under rapid cooling. The microstructures produced under various fabrication parameters directly influence the shear strength of the joints. When ZrO₂ and Ti-6Al-4V couples were brazed at 1173 K for 10 min and then cooled at a rate of 5 K/min, the maximum shear strength of 95 MPa was obtained.