Effect of Ag on properties of Zn-Al brazing filler metal

Effects of Ag on the melting temperature,spreadability,brazing seam microstructure of Zn-Al filler metal and the mechanical property of brazed joint were studied respectively.Results show that with the addition of Ag,the melting temperature rises slightly,the spreadablity and the mechanical property of the brazed joint are improved,and the microstructure of the brazed joint is improved significantly.When the Ag content applied in the brazed joint is up to 3.3%,the filler metal shows the best mechanical property of the brazed joint;when the Ag content exceeds 3.3%,the mechanical property of the brazed joint remains stable.The addition of Ag can refine the CuAl₂ brittle phase in the brazed seam,which decreases the stress concentration and enhances the brazed joints.In general,the brazing filler metal with 3.3% Ag has the best comprehensive properties.