Chromium Nitride (CrN)
Chromium Nitride (CrN) is a light silver-colored coating with excellent performance in some specific applications.
CrN tends to sublime when heated to high temperature. Sublimation is the vaporization or evaporation of a solid material without melting first. A common example is the sublimation of ice in cold winter, causing drying of clothing left outside at temperatures well below the freezing point of water.
This sublimation eliminates the tendency of micro-droplet formation encountered during thermionic evaporation of metals, such as Titanium and to a lesser degree, Zirconium. This yields a smoother deposit, which is advantegeous in machining soft, pliable materials, such as electolythic Copper.
Chromium Nitride is also used for deep drawing applications.
It should be noted that often similarly good results can be achieved with TiN and TiCN if their surfaces are smoothened by, e.g., Crocus Cloth.