Mechanical property of alumina ceramic/AgCuTi/Kovar alloy brazed joint

In order to obtain reliable joint of alumina ceramic and Kovar alloy, the shear strength of alumina ceramic/AgCuTi/Kovar alloy brazed joint was tested to evaluate the mechanical property of the joint. Effect of processing parameters including brazing temperature and holding time on the joint mechanical property was also discussed by optical microscope, SEM and EDS. Results showed the maximum shear strength was 144 MPa, which was achieved when the brazing temperature was 900°C and holding time was 5min. In this case, fracture happened mainly at the alumina ceramic/brazing alloy interface and partly at TiFe₂, TiNi₃ intermetallic compounds layer. The TiFe₂, TiNi₃ intermetallic compounds increased as the brazing temperature and holding time increasing resulted in the decrease of alumina ceramic/AgCuTi/Kovar alloy joint property.