Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts.
Anodizing increases corrosion resistance and wear resistance, and provides better adhesion for paint primers and glues than does bare metal. Anodic films can also be used for some cosmetic effects with thinner transparent coatings or thicker porous coatings that can absorb dyes.
The anodizing process changes the microscopic texture of the surface and changes the crystal structure of the metal near the surface. Thick coatings are porous, so a sealing process is often needed to achieve corrosion resistance.
Anodized aluminum surfaces, for example, are harder than aluminum, but can have good wear resistance that can be improved with increasing thickness or by applying suitable sealing substances. Anodic films are generally much stronger and more adherent than most types of paint and metal plating, but also more brittle. This makes them less likely to crack and peel from aging and wear, but more susceptible to cracking from thermal stress.
Valence offers every variety of anodizing, including but not limited to:
Type I Anodize
- Boric Anodize – Boric-Sulfuric Acid Anodize (BSAA) is an alternative to chromic acid anodize (CAA), that builds a thin-film anodic coating and provides corrosion protection and a mechanical bond. This is a
non– chromated, environmentally friendly solution.
- Tartaric Anodize – Tartaric-Sulfuric Anodize (TSA) is an alternative to chromic acid anodize (CAA), that builds a thin-film anodic coating and provides corrosion protection and a mechanical bond. This is a
– non , environmentally friendly solution – typically specified in Airbus programs like the A350. chromated
- Chromic Anodize – Chromic Acid Anodize (CAA) creates the thinnest anodic
coating,while providing the same corrosion resistance as other types of anodization, such as boric or sulfuric.
- Sulfuric Anodize – Sulfuric Acid Anodize (SAA) is used when hardness and abrasion resistance is required on a
part,and creates a surface that is harder than traditional chromic anodizing.
- Hard Anodize – Hardcoat anodize is created is a sulfuric acid bath, but results in a much thicker surface anode coating than traditional sulfuric acid anodizing.
Phosphoric Acid Anodize
- Phosphoric Acid Anodize – Phosphoric Acid Anodize (PAA) is most commonly used in bonding applications, as it provides a superior porous surface for bonding to composites.