Abstract: A coating is disclosed herein together with a method of forming that coating on metal surfaces of an internal combustion chamber. The coating is deposited for example, on the combustion surface of a piston to form a thermal barrier and thus enable higher temperatures to be sustained within the chamber. Combustion at higher temperatures achieves a more complete fuel burning thus increasing performance and reducing emissions. The coating is formed on the combustion surface by successively depositing layers of different materials preferably applied utilizing a plasma flame spray process. More particularly, the formation of the coating on the combustion surface involves preparing the surface as by grit blasting and then initially depositing a thin (approximately 0.001 - 0.003 inches) nickel aluminum alloy layer. Thereafter, a second thicker layer (approximately 0.003 - 0.