Interface Microstructure and Tensile Properties of Different-Bevel-Angle Galvanized Steel/Aluminum Alloy Joint by Laser Fusion Brazing

6061-T6 aluminum alloy plate and AISI 1045 galvanized steel plate were welded by laser fusion brazing with ER4043 welding wires; the bevel angle of the aluminum alloy plate was 30°, and that of the steel was 30° and 60°, respectively.The microstructure and micro-zone composition of the brazing interface on the steel side were studied, and the tensile properties of the joint were tested.The results show that zinc-rich areas and microvoids were formed at weld toe and weld root on the brazing interface of the joint when the bevel angle of steel plate was 60°, and a continuous intermetallic compound layer was formed at other areas on the interface.For the joint wth the steel plate bevel angle of 30°, zinc-rich areas were only formed at the weld toe, and a continuous intermetallic compound layer was formed at the entire brazing interface.In the two joints, the thickness of the intermetallic compound layer on the lower area of the steel plate groove surface was higher.The thickness of the intermetallic compound layer in the joint with the steel plate bevel angle of 30° was greater than that with the steel plate bevel angle of 60°.The average tensile strength of joints with the steel bevel angles of 30° and 60° was 120.3, 151.7 MPa, respectively.The two joints fractured at the steel/weld interface during tension, and both fractured in cleavage fracture form.