Vapour deposition of wear-resistant surfaces

Abstract

Many hard and wear-resistant coatings can deposited from the vapour phase. With the exception of gaseous nitriding and carburising, these are overlay coatings and generally consist of refractory carbides and nitrides, although bearing metals can also be deposited in this way. Some of the wear-resistant metals and compounds deposited from the gas phase are listed in Table 1. In general these materials are extremely hard ie > 2000 VPN, ~md are used when this p}operty is of utmost importance. They are also chemically inert and therefore combine some corrosion resistance with their hardness. It is probably this combination which results in their interesting tribological properties. For example a titanium carbide coating protects a cutting tool from wear because it reduces the tendency for cold welding between tool and work piece.