Ultrasonic brazing of Zr-based bulk metallic glass and 1060 Al alloy using Zn-3Al filler metal

Ultrasonic brazing of Zr-based bulk metallic glasses (Zr-BMG) and 1060-Al alloy dissimilar was realized by using a Zn-3Al filler metal. A firm metallurgical bonding was obtained at the dissimilar joint interfaces. In the initial stage, a single-phased Zn50Al25Zr25 IMC layer was found on the Zr-BMG surface. Prolonging the brazing time, the excessive growth of the Zn50Al25Zr25 IMC layer inhibited the diffusion of Al from brazing seam to the reaction front, which induced the composition fluctuation of Al and thus the formation of Zn50Al25Zr25/Zn-rich phase composite layers on the Zr-BMG surface. The shear strength of joints was affected by the interfacial reaction phase, and the highest value obtained was 68 MPa.