Electroplated coatings of nickel, chromium, silver, tin and other metals may be applied to PCP Aluminium cast plate, to obtain a specific properties such as metallic appearance, improved resistance to wear and corrosion, increased electrical conductivity, improved solderability, and frictional properties. Because of the natural oxide film on its surface, aluminum will respond properly to procedures usually employed when other metals are prepared for plating. Different conditioning treatments must be used to obtain a satisfactory base for plating aluminum.

The pretreatment most often used commercially is the zinc immersion process. The Alstan Process*, involving activation of the surface with tin, is also widely used. Since cast plate is produced with DC casting technology, it can exhibit porosity which may affect the appearance.

*Trademark of Atotech, USA

PCP Aluminium Cast Plate has been used in a variety of anodizing processes for commercial applications under several trade names. Anodizing processes generally employ sulfuric or chromic acid as the electrolyte. However, other acid electrolytes produce anodic coatings with specific characteristics. Anodized finishes are both decorative and functional. Hardness can be controlled by the thickness and density of the anodizing finish. Coatings formed in a 15% (wt) sulfuric acid electrolyte maintained at 21°C, 1.1 amp/dm2 current density can vary in thickness from 0,0025 mm to 0,020 mm.

Due to alloy composition and cast structure, the anodized finish can exhibit a non-uniform gray appearance. However, this will not affect its corrosion or wear resistance. Alca5^® will respond slightly differently to this anodizing practice depending, on the selected process. By altering the voltage and/or current density, the difference in rate of coating growth for Alca5^® may be modified to achieve the desired coating thickness.