Study on low temperature brazing of magnesium alloy to aluminum alloy using Sn–xZn solders

In this article, a series of Sn–xZn solders are designed for joining Mg/Al dissimilar metals by low temperature brazing. The effect of Zn content in Sn–Zn solders on microstructure evolution and mechanical properties of the different brazed joints are investigated. The experimental results indicate that Sn–30Zn alloy is identified as the optimized solder. Al–Sn–Zn solid solutions form and disperse in the brazing zone of the Mg/Sn–30Zn/Al brazed joint, decreasing the risk of embrittlement of the brazed joint. The average shear strength of Mg/Sn–30Zn/Al brazed joint can reach 70.73 MPa. The joint fractures in the coarse blocky Mg2Sn intermetallic phases in the center of the brazing zone.

► Low temperature brazing is utilized for joining Mg/Al dissimilar metals.
► Zn content in Sn–Zn solders determines microstructure and performance of the joints.
► Dispersive distribution of Al–Sn–Zn solid solutions strengthens the Mg/Al joints.
► The average shear strength of Mg/Sn–30Zn/Al brazed joint attains 70.73 MPa.