Plasma spraying is a surface enhancement and modification technique that endows substrates with properties such as wear resistance, corrosion resistance, high-temperature oxidation resistance, electrical insulation, thermal insulation, radiation protection, reduced friction, and sealing. The process employs a plasma arc, driven by direct current, to heat materials such as ceramics, alloys, and metals to a molten or semi-molten state, which are then sprayed at high speed onto the pre-treated surface of a workpiece to form a well-adhered surface layer.