Analysis of CMT Advanced+P welding-brazing characteristics of 7075/TC4 dissimilar metals

Based on CMT advanced + P welding method, the welding-brazing test of 7075 aluminum alloy and TC4 titanium alloy lap joint was carried out using ER5356 filler metal. The microstructure and mechanical properties of the joint were analyzed. The results showed that the welded joint was composed of weld zone, heat affected zone and brazing interface zone. The weld zone was mainly composed of equiaxed grains. The grains in the heat affected zone of aluminum alloy showed rolling characteristics, and a certain amount of intermetallic compounds were precipitated near the grain boundary. In the brazing interface area, there existed a serration-shaped intermetallic compound layer growing from the lateral weld area of titanium. The thickness of the compound layer was 1 ~ 2.5 μm and mainly composed of Al-Ti intermetallic compounds. The fracture location of the joint was near the heat affected zone of the aluminum alloy, and the tensile fracture type was mixed fracture, with the maximum shear strength of 293.1 MPa.