1. The 4 Intermetallic Alloy Phases
Unlike paint coatings that adhere solely through surface mechanical tension, hot-dip galvanizing produces an authentic metallurgical alloy bond:
1. **Gamma Layer (Γ):** Thin base boundary layer (75% Zn, 25% Fe) measuring 200–250 DPH hardness.
2. **Delta Layer (δ):** Hexagonal columnar crystals (90% Zn, 10% Fe) with hardness exceeding structural base steel (up to 300 DPH), providing extreme abrasion resistance against mining rocks and loader impacts.
3. **Zeta Layer (ζ):** Monoclinic crystals (94% Zn, 6% Fe).
4. **Eta Layer (η):** 100% pure molten zinc outer shell offering sacrificial cathodic protection: if scratched down to bare steel, surrounding zinc sacrifices itself galvanically to heal the scratch.