Abstract:
Ti+Nb/Mo thin films were deposited onto Al
2O
3 ceramic by magnetron sputtering with a subsequent nickel-plating to ensure the robust brazing of Al
2O
3 ceramic to Kovar alloy using the filler of AgCu28. Microstructures of the metallization layer and the brazing joints of Al
2O
3/Kovar were investigated systematically by scanning electron microscopy (SEM) and energy dispersive X-ray (EDS). The results show that the interfacial reaction layers are created between filler alloys and base materials. Interdiffusion of Ni and Cu at the interface of AgCu/Kovar resulted in the formation of the reaction layer. The metallization layer plays an important role in hindering the formation of intermetallic compounds and relieving residual thermal stress at Al
2O
3/AgCu interface. In addition, the presence of eutectic region arising from nickel-plating can improve the thickness of the brazing seam and therefore a good bonding betweenAl
2O
3 ceramic and Kovar was achieved.