The study of microstructure, corrosion resistance and mechanical properties of ultrasonic assisted welding-brazing of Ti–Mg
Chuan Xu, Xinjian Yuan
Abstract
In order to refine microstructures, enhance corrosion resistance and mechanical properties of Ti/Mg joints, the ultrasonic vibration assistance (UVA) treatment were applied during the welding-brazing of Ti/Mg dissimilar metal. The specific impacts and mechanisms of UVA on the microstructure evolution and mechanical enhancement were investigated. The experiment results express that with the aid of UVA process, the coarse grains in weld zone were effectively refined attributed to ultrasonic induced acoustic streaming and cavitation effects. Meanwhile more tenacious and adherent protective layer of Mg(OH)2 occurred and reduced corrosion rate of weld zone. Under the optimized ultrasonic parameter of 1.2 kW, the mechanical property of Ti/Mg joint was improved 11.4% to 225 MPa, compared with joints without the aid of ultrasonic treatment.