Within the area of surface engineering Plasma Coating has become a very effective process for improving the surface characteristics of engineering components. Application of this coating includes corrosion protection, wear and abrasive resistance, dimensional restoration of worn or corroded parts etc.

In addition to original equipment applications, thermal spray coatings are used to repair parts worn and damaged in service, and restore dimensions to machined parts. Thermal spray coatings are used to restore the dimensions of components that have been worn or corroded including undersized bearings.
Although the thermal spray coating does not add any strength to the component, it is a quick and economical way to restore the dimensions of parts. Subsequent grinding operations are often needed to smooth the coating's surface and to bring the final dimensions into their appropriate tolerances. Thermal spray coatings for dimensional restoration are being used in every manufacturing industry.

In plasma spray coating process, plasma arc spray energy is used to heat the coating material (metallic powder) to a molten or semi molten state.  The resultant heated particles are accelerated and propelled towards a prepared surface  by process gases. Upon impact, a bond forms with the surface, with  subsequent particles causing thickness build-up and forming a lamellar structure.

Plasma spray coating can be applied to finely machined, fully heat treated parts without changing the properties of the part and without excessive thermal distortion of the part. Some of these coatings are quite porous with the advantage that they act as reservoirs for lubricants.