Effect of Brazing Temperature on Microstructure and Properties of Spark Plasma Brazed Joint of 5A06 Aluminum Alloy

5A06 aluminum alloys are widely used in the precision manufacturing parts such as liquid-cooling and waveguide components, because of their high strength, excellent corrosion resistance, as well as good thermal conductivity and machinability. In this paper, spark plasma brazing by using Al-Cu-Si-Ni solder foil was performed to realize the joining of 5A06 aluminum alloy. The influence of brazing temperature on microstructure and mechanical properties of brazed 5A06 alloy joints was investigated. The results show that at the brazing temperature of 510-530 degrees C, pressure of 4 MPa and holding time of 10 min, the tensile strength of brazed joint increase with the temperature increasing. The maximum tensile strength is 152 MPa, wherein ductile fracture morphology mainly composed of fine and homogeneous dimples is obtained at 530 degrees C. With the combined effect of low melting point solder, welding pressure, pulse electric field and short holding time, the brazing zone is thinner, while matrix grains are finer and brittle phases are distributed uniformly. Meanwhile, the interfacial atomic diffusion and reaction are enhanced, leading the strengthened microscopic metallurgical bonding by fine Mg2Si and Si particles.