ANODIZED ALUMINIUM CASTINGS

"VJP has setup a new anodizing plant to accomplish customer or

ders on time. This page provides the details of the anodizing plant at VJP and also the process details for technical understanding."

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 bare metal. Anodic films can also be used for a number of cosmetic effects, either with thick porous coatings that can absorb dyes or with thin transparent coatings that add interference effects to reflected light. Anodizing is also used to prevent galling of threaded components and to make dielectric films for electrolytic capacitors. Anodizing most closely resembles standard electroplating. When a reactive metal is suspended in an electrolytic bath as an anode and current is passed through the bath oxygen is produced at the anode surface. This oxygen reacts with the metal to form a thin oxide film that generates colors. The transparent oxide increases in thickness in relation to the amount of voltage applied. At any given voltage the oxide will grow to a specific thickness (i.e. color) and stop, having reached a stage where current will no longer pass.

Sulphuric Anodizing
Sulfuric anodize, commonly referred to as Type II anodizing, is formed by using an electrolytic solution of sulfuric acid at room temperature and a current density of 15 to 22 Amps per square foot. The process will run for 30 to 60 minutes depending on the alloy used. This will produce a generally clear coating, depending on sealing, a minimum of 8ìm thick. One third of the coatingsquare foot. 

The process will run for 30 to 60 minutes depending on the alloy used. This will produce a generally clear coating, depending on sealing, a minimum of 8ìm thick. One third of the coating

Value Additions

• Can handle large size parts
• Sizes of 4.5mx2 m.
• Coloring.
• Integrated paint shop.