Effect of Mg Addition on Microstructure and Sacrificial Anode Protection Performance of Hot Dip Al-5Zn-4Si-xMg Coating

The effect of Mg addition on the microstructure and sacrificial anode protection performance a hot-dip Al-5Zn-4Si-xMg coating was studied by scanning electron microscopy (SEM-EDS), an X-ray diffractometer, electrochemical workstation. results showed that Al-Zn-Si alloy composed Al-rich phase Zn-rich phase. MgZn2 appears after addition. When increased to 0.15 wt.%, Mg2Si began appear in alloy. consisted Si particles, content Al + Zn eutectoid coating. In full immersion corrosion test coating, order resistance 0.15% > 0.2% 0.05% 0 process Al-5Zn-4Si-0.15Mg with increase immersion, self-corrosion current decreased, best.