Nanocoatings for engine application

In this paper, a review of engineering coating for engine application is presented. Issues relating to dimensional stability, tribological properties, lubrication, coefficient of friction, hot hardness, amenability for honing, surface roughness and topography, residual stress, adherence, damage tolerance and resistance, pores density and conditions and cost performance are discussed. There exist advantages and limitations of conventional materials systems and techniques such as chemical-vapor-deposited diamond-like carbon (DLC) coating, plasma sprayed metal matrix composite coating, tribologically functional ceramic coatings, etc. Nano-grains of a crystalline phase hold promise to solve several such problems present in conventional coatings. In addition, surface-related problems are addressed for high performance engines and hydrogen powered automotive engines.