Interfacial Reaction for Brazing Al₂O₃ Ceramics in Atmospheric Environment with CuO Auxiliary Ag_{72Cu28 Eutectic Solder}

A method with CuO auxiliary Ag72Cu28 eutectic solder was used to realize brazing Al2O3 ceramics in atmospheric environment. The shear strength and morphology of brazed joint, interfacial reaction products and mechanism were studied. The results show that when brazing temperature was 1 050 ℃, holding time was 10 min and mass fraction of CuO was 10wt%, shear strength of the joint was the highest, the srength was 39.04 MPa. During brazing, liquated Cu moved to the surface of Al2O3 ceramics with the help of CuO, and then the solder was easier wetting and spreading on Al2O3 surface. Interface transition layer could be observed clearly in brazed joint, and interfacial reaction products were mainly CuAl2O4 and CuAlO2 phases.