Microstructure evolution and bonding mechanism of ZrO2 ceramic and Ti-6Al-4V alloy joints brazed by Bi2O3-B2O3-ZnO glass paste

Ceramics and metal joinings have been widely employed in aerospace, dental implants, and the electronic packaging industry for fabricating multifunctional components. In this study, the 35Bi2O3-50B2O3-15ZnO (mol.%) glass has been employed for joining the ZrO2 ceramic and Ti-6Al-4V alloy. The effect of brazing temperature on the microstructure evolution, mechanical properties, and bonding mechanism of brazed joints has been analyzed. The microstructure of the ZrO2/glass/Ti-6Al-4V joints and the content of Bi4B2O9, Bi2O3 and Bi24B2O39 precipitated crystals in glass were found to be dependent on the brazing temperature. The reaction product of Bi4Ti3O12 was identified in the glass/Ti-6Al-4V interface because of the chemical reaction between the oxidized layer of Ti-6Al-4V alloy and glass. A maximum shear strength as high as 48.8 ± 5.2 MPa was obtained. Our work, thus, demonstrates that the 35Bi2O3-50B2O3-15ZnO glass is an effective bonding material for joining ZrO2 ceramic and Ti-6Al-4V alloy under low temperature in an ambient atmosphere.