• Annealing - reduction in strength of metals. Typically softens the metal. This is important for the cure of coatings and the various substrates. Aluminum and bearings are negatively affected by high temperature during the cure process.
  • Electrical conductivity - the ability to transfer electrons through a coating. This property is important for the sacrificial protection of cermets to the substrate steel. It also provides the protection from undercutting (rust) of the coating.
  • Emissivity - the ability of a material to either absorb or reject heat. Low emissivity reflects heat (similar to aluminum foil). High emissivity attracts heat.
  • Ferrous/non ferrous – iron containing material that can rust or heavily oxidize with thermal cycles.
  • Fretting – erosion of metal by continuous agitation to the surface.
  • Galling – a cold welding phenomenon that occurs when protective oxide layers expose reactive metal. Similar metals undergo galling and seize to each other. This does not occur on carbon steels.
  • Galvanic activity - the ability to transfer electrons from an anode to a cathode. Important for sacrificial coating protection from oxidation to the substrate.
  • Oxidation (thermal and chemical) – chemical change in a substrate or other material typically resulting in oxide formation (rust). This will be red or brown on steel or iron containing substrates and white on aluminum.
  • Passivation – a boundary layer that improves the protection of the primary coating layer. Topcoats are a form of passivation.
  • Pre-ignition causes – engine timing affects the combustion within an engine. Pre-ignition results when the firing is performed before the piston has returned to the top of the chamber. This causes knocking in the engine and results in damage to the piston, crank, and valves.
  • Sacrificial – the cermet coating’s ability to transfer protective electrons to the substrate so that undercutting and corrosion don’t form on the interface of the coating and the part.
  • Thermal conductivity – the ability of a coating or other material to transfer heat through the material. Low thermal conductivity is good for insulation benefits.
  • Thermal fatigue - loss of carbon from the substrate steel resulting in pitting and scale formation (rust).