ZrO2 ceramic/stainless steel joints were fabricated by pressureless brazing using a Ag-Cu filler metal and a TiH2 powder precoating. The microstructure and microchemistry of the joint cross section were characterized and analyzed by means of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The effects of brazing conditions on the joint shear strength were also investigated. The results showed that there existed three zones with distinct microstructural differences crossing the brazing interlayer. A reaction layer and a Ti-rich sublayer were formed at the ZrO2/filler interface. The influence of the brazing temperature on the joint strength was more remarkable than that of the holding time. In the experimental condition ranges, the joint strength first increased, and the maximum shear strength was over 90MPa with the optimized condition. Most of the joint fractures developed in the ceramic matrix near the ceramic/filler interface.

Keywords: Brazing, Zirconia, Microstructure, Interface, Mechanical Properties.