CVD is used to grow a thin layer of advanced materials on the surface of a substrate. A non-volatile solid film on a substrate by the reaction of vapor-phase chemicals that contain the required constituents. The reactant gases are introduced into a reaction chamber then decomposed and reacted at a heated substrate to form the film. Some practical uses of CVD include growing carbon nanotubes, bonding diamond grit to a silicon substrate, or producing thin films with the potential to increase resistance to abrasion and wear in metal parts.