Thermal spray describes a group of processes in which finely divided metallic or nonmetallic materials are deposited in a molten or semi-molten state on a prepared surface. The heat source is a combustion flame, a plasma jet, an r.f. inductively coupled discharge, or an arc struck between two consumable wires. Historically a surfacing technology, thermal spray has moved from a coating to a material processing technology.Thermal Spray Processes have seen a steady growth in the number of industrial applications and is now used on a daily basis. Some of the most typical applications include:Environmental and thermal barrier coatings for the protection of gas turbine components.Coatings on medical implants promoting bone growth while providing biocompatible surfaces.Wear and/or corrosion resistant coatings on engineering structures or automobiles and heavy duty mining machinery.The aerospace and power generation industries are now dependent on thermal spray technology.