PLATED SEAL FACE P019
In this design a hard coating is sprayed or plated on the base material. The main problem with this configuration is that the base material and the hard coasting have two different thermal expansion rates that will often cause the hard surface to crack. Please see heat-check.
Among the hard-coatings you will find:
- Tungsten carbide
- Silicon carbide
Most of these coatings have a thin cross-section making them un-satisfactory for providing corrosion resistance. Their function is limited to providing a wear surface in those applications where no heat problems are anticipated.
Plasma spray is not recommended for mechanical seal faces. If you must use a spray coating the D gun process is superior because it creates a chemical rather than a mechanical bond with the base material.