Phosphating (Zinc & Manganese)
Phosphating is the application of a porous crystalline coating usually applied to ferrous-based materials, the process is non-electrolytic with the phosphate layer being produced by catalytic action between the component material and the Phosphating solution, this catalytic action producing an exceptionally strong bond of the phosphate layer to the component surface.
The coating produced is crystalline and porous and forms a very good base for subsequent applications. As an undercoat for paints, it dramatically improves adhesion of the painted layer and the application of specialised oils and greases will enhance the corrosion performance of the component or provide lubricity for subsequent manufacturing operations.
Accurate Edge offers two types of Phosphating, Zinc Phosphate which gives a finer grain with a wider range of thicknesses being achievable, or Manganese Phosphate which is limited to heavier films. The Manganese phosphate coating also has a different crystalline structure to zinc phosphate, this structure is laminar rather than columns, compressive and imparts greater corrosion resistance and lubricity without the need for additional coating, although these can be specified if required. Manganese phosphate is particularly good for components where “wearing/running in” is required, and because it is a compressive coating continues to offer lubricative properties for extended life.
Key Properties of Manganese Phosphating
- Corrosion resistance
- Friction reduction
- Uniform, smooth, thin-film deposit
- Thrust washers