The term, "functional coating" has often been used as a synonym for tool coating: typically the coatings used are Titanium Nitride (TiN), Chromium Nitride (CrN), Zirconium Nitride (ZrN), Titanium Carbon Nitride (TiCN) and Aluminum Titanium Nitride (AlTiN). They are applied at higher temperatures and in greater thickness than other PVD coatings. While coating color and surface uniformity are important, the main emphasis is on hardness, density, mechanical bond strength to the part substrate, and overall wear resistance. Typical applications include instrument blades, knives, augers, drills, automotive wear parts, machine bits and metal forming tools.
Machine process enhancements have led to the development of a new class of coatings. Many of the performance attributes listed above are complemented by the addition of "release or non-stick" properties. This has been a very important development for applications in the Plastics Industry involving calibrator plates for extruded vinyl windows, extruder screws, compression rings, injector pins, etc. There has also been a dramatic increase in tool life (e.g. metal forming dies, stamping tools, etc.) due to increased lubricity and anti-galling properties.