Ultrasonic brazing method for high-volume-fraction silicon carbide particle enhanced aluminum-base composite and low-expansion alloy

The invention relates to an ultrasonic brazing method for an aluminum-base composite and low-expansion alloy, in particular to an ultrasonic brazing method for a high-volume-fraction silicon carbide particle enhanced aluminum-base composite and low-expansion alloy. The ultrasonic brazing method solves the problems that existing brazing methods for connection of the high-volume-fraction silicon carbide particle enhanced aluminum-base composite and the low-expansion alloy are complex in process and high in cost, connection temperature and joint residual stress. The method includes: firstly, cleaning to-be-brazed surfaces of the aluminum-base composite and the low-expansion alloy; secondly, coating a metal layer on the to-be-brazed surface of the low-expansion alloy; thirdly, lapping the to-be-brazed surfaces of the aluminum-base composite and the low-expansion alloy, wherein brazing materials are arranged on the lateral side of a lapping joint to form a to-be-brazed part; and fourthly, heating the to-be-brazed part, ultrasonically vibrating, heating, preserving heat, pressurizing at the joint while ultrasonically vibrating, and performing furnace cooling to the room temperature, so that ultrasonic brazing is completed. The ultrasonic brazing method is simple in process, low in cost, low in connection temperature and high in joint residual stress. The ultrasonic brazing method is used for the brazing field.