Si particulate-reinforced ZnAl based composites joints of hypereutectic Al50Si alloys by ultrasonic-assisted soldering

Abstract Hypereutectic Al Si alloy plates were joined by ultrasonic-assisted flux-less method using Zn 5Al filler metal at 420 °C in air. The influence of ultrasonic time on the microstructure and mechanical property of joints was investigated. The introducing of ultrasonic into soldering processes had effects on accelerating Si particles distribution in a Zn-based filler metal, and also affected the solidification microstructures of Zn Al alloys. The shear strength of joints had correlation with the distribution of Si particles and types of Zn Al alloys, and increased with the ultrasonic time. The highest average shear strength of joints reached to ~ 108 MPa, and the fracture mainly occurred at the base metal of Al 50Si rather than the Si particulate-reinforced Zn Al based composites joints, indicating the strength of joints was stronger than that of Al 50Si based metal.