Microstructures and properties of 5A06 alloy brazed joint with Al-Cu-Si-Ni filler metal

The vacuum brazing of 5A06 aluminum alloy using Al-Cu-Si-Ni filler metal was investigated at different brazing processes.The effects of brazing temperature and time on the shear strength and microstructures of the joints were studied.Microstructures and phase in the brazed joints were studied by means of scanning electron microscopy analysis（SEM）and Energy Disperse Spectroscopy（EDS）.Shear strength and micro-Vickers hardness of joints were tested.The results show that the different intermetallic compounds such as Mg₂Si and CuAl₂ formed in the bonding zone.The shear strength of joints brazed at 550 ℃is higher than that at 540 ℃ and increases with the brazing time being increased.The average shear strength of the joints brazed at 550 ℃for 30 min achieves 74 MPa.