Lubricants and Wear Coatings for Titanium Available to Purchase

Titanium has poor resistance to wear and galling and is among the most difficult of metals to lubricate. This condition is attributable to the nature of the adsorbed gas film on the metal's surface. Emphasis has been placed on modifying the surface to improve wear and lubrication properties. Liquid lubricants were found to have little effectiveness on untreated titanium, but solid lubricants such as molybdenum sulfide (MoS₂) applied to properly roughened surfaces can give useful wear life. Chemical and electrochemical conversion coatings combined with mechanical or chemical roughening provide the optimum pretreatment for bonding solid lubricants to titanium. Surface hardening processes such as nitriding and oxidizing produce wear resistant surfaces which may be lubricated by standard liquid lubricants, even at high loads. Platings of chromium or nickel on titanium are promising from the standpoint of wear resistance, but poor adhesion limits their usefulness. The most practical treatments for improving the wear resistance of titanium involve spraying of metallic or ceramic compounds such as molybdenum, titanium oxide, chromium oxide, and tungsten carbide.