Study of Zn6Al6Ag Alloy Application in Ultrasonic Soldering of Al2O3–(Al/Al2O3) Joints

The aim of this research is to characterize the soldering alloy Zn6Al6Ag, and to study the ultrasonic soldering of an Al2O3/metal–ceramic composite (Al/Al2O3). Zn6Al6Ag solder presents a quasi-eutectic structure with a melting point around 425 °C. The solder microstructure consists of a (Zn) + (Al) matrix, reinforced with a silver AgZn3 phase. A bond with the metal–ceramic composite was formed due to the dissolution of Al in the liquid Zn solder. The Al2O3 particles were put into motion, and a new composite was formed on the boundary. The Zn6Al6Ag solder also wetted the surface of the Al2O3 ceramic. A decisive effect on bond formation was caused by zinc and aluminum, whose oxides were combined with the oxides of ceramic material during in-air soldering. An adhesive bond was formed. The average joint shear strength of Al2O3/metal–ceramic composite (Al/Al2O3) was found to be 23 MPa.