Surface treatment is the most critical technical stage in protecting the aluminum core from environmental chemical and physical impacts. AMS utilizes a dual-treatment process: Mechanical Texturing and Surface Electrochemistry.
1. Brushing Process (Mechanical Texturing)
This is a physical process applied to the aluminum surface post-extrusion. AMS utilizes stainless steel wire brush systems or abrasive belts with grit sizes ranging from #120 to #320.
- Principle: Mechanical friction breaks down the thin natural oxide layer on the surface, creating microscopic, parallel, and uniform scratch patterns.
- Control: The rotation speed of the grinding rollers and the contact pressure are precisely calculated to ensure the nominal thickness of the profile is not altered by more than 0.02mm.
2. Anodizing Process (Standard MIL-A-8625)
After the brushing process, the aluminum enters electrochemical baths to create a hard protective layer.
- Degreasing: Removal of solvents and organic impurities.
- Etching: Cleaning micro-burrs left after the brushing stage.
- Anodizing: In a sulfuric acid (H2SO4) solution, the aluminum acts as the anode. Direct current stimulates the formation of an aluminum oxide layer (Al2O3) with a hexagonal cell structure.
- Coloring: Utilizing metal salt electrolysis (Tin, Nickel) to deposit color particles deep into the pores of the oxide layer.
- Sealing: This is the most crucial step. The aluminum is immersed in hot water or a chemical solution to close the surface pores, locking in the color particles and preventing the entry of corrosive agents.
3. Coating Inspection Standards
The anodic coating at AMS reaches a thickness of 10 to 25 micrometers depending on project requirements. Our products comply with the ISO 9227 salt spray test standard, ensuring superior resistance to coastal environments.
