Powertrain component with adherent film having a graded composition

An internal combustion engine including a powertrain component such as, but not limited to a valve lifter, the component having:

• a coating system including a film and an interlayer formed on a wear surface of the component;
• the film being selected from a first group comprising at least one of amorphous hydrogenated carbon, silicon-doped amorphous hydrogenated carbon, boron-doped amorphous hydrogenated carbon, nitrogen-doped amorphous hydrogenated carbon, boron nitride-doped amorphous hydrogenated carbon, or metal-doped amorphous hydrogenated carbon, the film imparting characteristics of low friction and wear resistance to the component;
• the interlayer being formed between the film and the component, the interlayer being selected from a second group comprising at least one of silicon, silicon carbide, silicon nitride, and boron nitride, the interlayer accommodating stresses engendered by formation of the film, and providing mechanical support to the film, and chemical compatibility between the film and the substrate, and thereby improving adherence of the film to the substrate,
• the component being selected from at least done of a ceramic and a metal including one or more of aluminum, an aluminum-silicon alloy, an aluminum-copper-silicon alloy, magnesium, a magnesium alloy, aluminum nitride, titanium, a titanium-aluminum alloy, and an aluminum alloy.