Vacuum brazing of biomedical TNZ alloy to ZrO2 ceramic using Sn-Zr filler: interfacial microstructure and mechanical properties

The Sn-Zr filler metal is developed to braze Ti-13Nb-13Zr (TNZ) alloy and ZrO2 ceramic for biomedical field. The impact of brazing processing parameters on the interfacial microstructure as well as mechanical properties is comprehensively examined and discussed. The typical interfacial microstructure of the joints is TNZ/Ti6Sn5/Ti6Sn5 + ZrSn2 + beta-Sn/m-ZrO2/t-ZrO2, which is obtained at 700 degrees C for 30 min. Zr active element contributes to the metallurgical bonding between brazing seam and ZrO2 substrate. As the brazing temperature and holding time increase, there is a rise in the quantity of Ti6Sn5 phase and m-ZrO2, while the content of ZrSn2 phase declines. The brazed joints exhibit an optimum shear strength of 38.8 MPa when joints are brazed at 700 degrees C/30 min. The amount of ZrSn2 phase and m-ZrO2 has a powerful influence on mechanical properties of joints.