Accession Number : AD0711667

Title :   A STUDY OF THE EFFECTIVENESS OF SELECTED ANTIWEAR ADDITIVES IN SYNTHETIC ESTERS.

Descriptive Note : Final rept. Jan 68-Jun 69,

Corporate Author : AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Davis,Kenneth A.

Report Date : JUL 1970

Pagination or Media Count : 89

Abstract : The effectiveness of selected antiwear additives was evaluated using synthetic ester base stocks. Certain relations between chemical structure and effectiveness were determined. The investigations were conducted using the pin on disk apparatus developed by Wintershall/Baist. Di-, tri- and tetraester fluids were used in the investigation. The basic lubricity of the oils was found to increase with increasing molecular weight and viscosity. Additives containing chlorine, sulfur and phosphorus were investigated, as well as several organic acids and organometallic compounds. Phosphorus additives proved effective, while sulfur and chlorine containing materials showed little beneficial effect. Experiments using aliphatic acids showed long chain saturated acids to be more useful in decreasing wear than shorter chain or unsaturated acids. A limiting or optimum concentration for tricresylphosphate was determined. A series of experiments using alkyl- and arylphosphates showed their effectiveness to be related to their hydrolytic stabilities. The lower hydrolytic stability phosphates were most effective. Further experiments showed that the possible acidic impurities in tricresylphosphate are powerful antiwear additives. Certain organometallic compounds were found to have limited capability as antiwear additives. Overall results showed additives to have specific ranges of load over which they were effective, and proper selection of additives can result in an additive package to cover a wide load range. (Author)

Descriptors :   (*LUBRICANT ADDITIVES, WEAR RESISTANCE), (*PHOSPHATES, LUBRICANT ADDITIVES), (*HALOGENATED HYDROCARBONS, LUBRICANT ADDITIVES), (*FATTY ACIDS, LUBRICANT ADDITIVES), TEST METHODS, EFFECTIVENESS, ORGANIC SULFUR COMPOUNDS, IMPURITIES, CARBOXYLIC ACIDS, CHLORINE COMPOUNDS, MOLYBDENUM COMPOUNDS, TIN COMPOUNDS, ANTIMONY COMPOUNDS, DEGRADATION

Subject Categories : Lubricants and Hydraulic Fluids

Distribution Statement : APPROVED FOR PUBLIC RELEASE