UNDERSTANDING THE TRIBOLOGICAL CHEMISTRY OF CHOLRINE- AND SULFUR- AND PHOSPHORUS-CONTAINING ADDITIVES

OCTAVIO JAVIER FURLONG; FENG GAO; WILFRED T. TYSOE

ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY

AMER CHEMICAL SOC

Año: 2006 vol. 231 p. 100 - 100

0065-7727

Chlorine- and sulfur- and phosphorus-containing compounds are added to the base fluid to synthesize extreme-pressure (EP) lubricants. The surface chemistry lubricant additives is studied in ultrahigh vacuum. Similar reactions are carried out at higher pressures using a microbalance where film growth rates are measured from the change in sample mass. Both the nature of the surface film and the reaction activation energies are identical in both regimes where chlorinecontaining EP additives decompose forming films of iron chloride (FeCl2) or carbide (Fe3C), and that dialkyldisulfides react to form FeS and Fe3C. These results, when combined with wear data, can be used to model the EP behavior of model lubricants by assuming that the film acts to prevent seizure, and that seizure occurs when the film is completely removed. The tribological properties of evaporated and reactively grown thin films are investigated in ultrahigh vacuum to correlate film properties with their tribological behavior.