Microstructure and mechanical property of ultrasonic soldered joint of AZ31B magnesium alloys

In order to solve corrosion problem of soldered joint when fluxing agents were used, a technology of ultrasonic soldering was developed.A lap joint of magnesium alloy AZ31B was obtained successfully in air with ultrasonic aided.The microstructure and strength of the joint soldered by this method were studied.The effect of ultrasonic vibration time and width of clearance on shear strength of joint was investigated.The results indicated that ultrasonic vibration can remove the oxide layer on base metal.And the shear strength of joint reaches 80-90 MPa in the appropriate range of vibration time.The shear strength decreases when the width of clearance is too large or too small.The microstructures of joint are mainly α-Mg and Mg-Zn phases and the fracture mode is intergranular fracture.