Wetting mechanism of Sn to Zr50.7Cu28Ni9Al12.3 bulk metallic glass assisted by ultrasonic treatment

In this work, pure Sn was used to wet Zr50.7Cu28Ni9Al12.3 bulk metallic glasses (BMGs) assisted by ultrasonic treatment. Without ultrasonic treatment, pure Sn showed a non-wetting condition to BMG. Ultrasonic vibration facilitated the wetting of Sn to BMG. Prior to ultrasonication for 30 s, only physical adsorption formed at the Sn/BMG interface. Increasing ultrasonic time led to the alteration of the bond at the Sn/BMG interface from point contact to local surface contact, and to diffusion layer. Two bonding modes of order-order and order-disorder were discovered at the Sn/BMG interface. Cu content was higher than the other elements near the bonding interface. Longer diffusion distances of Sn into the BMG were obtained at high ultrasonic power, high temperature and large dip depth.