Zinc-aluminum alloy ingots are thin blocks cast by co-melting specified amounts of pure zinc and pure aluminum. In hot-dip galvanizing production, directly adding pure aluminum to the molten zinc bath is challenging because the bath temperature typically ranges from 470°C to 510°C, while pure aluminum's melting point is 660°C. However, when the alloy contains approximately 7% aluminum and 93% zinc, its eutectic temperature drops to around 380°C. Zinc-aluminum alloy ingots prepared in this ratio readily dissolve in the molten zinc bath, greatly simplifying the addition of required aluminum into the bath.
For practical production convenience and easier calculation of aluminum content in the molten zinc bath, alloy ingots composed of 10% pure aluminum and 90% pure zinc are also commonly used.
Key Technical Notes:
The eutectic composition (7% Al-93% Zn) ensures optimal fluidity and dissolution efficiency at galvanizing temperatures.
Higher aluminum content (10% Al) may slightly alter dissolution kinetics but provides a simpler formulation for quality control.
Both alloy ratios prevent solidification issues caused by aluminum's high melting point while maintaining effective corrosion resistance in the galvanized coating.
