Microstructure and mechanical properties of ultrasonic assisted soldering joint of Al-60Si alloy at low temperature

Ultrasonic-assisted low-temperature brazing of Al-60Si alloy was carried out with SnAgCu solder. The effects of brazing temperature and ultrasonic time on the mechanical properties and microstructure of the joint were investigated. High (240 ℃ to 360 ℃), the average mass fraction of Si particles in the brazing joint increases (1.11% to 7.17%), and the shear strength of the joint increases first and then decreases. The highest value during welding is 42 MPa; when the brazing temperature is fixed at 330 ℃, and the time that ultrasonic waves are applied to the substrate is increased (from 10 s to 70 s), the average mass fraction of Si particles in the brazing seam increases accordingly (from 5.13% increased to 9.18%), the shear strength of the joint showed a trend of increasing first and then decreasing, reaching the highest at 51 MPa when ultrasonic for 50 s.