Effect of al content on microstructure and corrosion resistance of Zn-Al-Mg alloy

In order to solve the solidification microstructure of Zn-1.7Al-1.1Mg alloy on the surface of steel plate during hot dip plating, the solidification path and microstructure of Zn-1.7Al-1.1Mg alloy were studied by Thermo-Calc thermodynamic software, differential thermal analysis (DSC) and scanning electron microscopy (SEM). The results show that during cooling from melting to room temperature, Zn-1.7Al-1.1Mg alloy begins to precipitate Zn-rich η phase at 386.5 °C, binary eutectic structure consisting of η phase and Mg 2 Zn 11 at 350.0 °C, and ternary eutectic structure consisting of η phase, Al-rich metastable β phase and Mg 2 Zn 11 at 343.4 °C,at 276.7 °C, β phase transforms into stable aluminum-rich α and η phases.