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Publication Citation: Enhancement of Engine Oil Wear and Friction Control Performance Through Titanium Additive Chemistry

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Author(s): J M. Guevremont; G H. Guinther; D Szemenyei; Mark Devlin; T-C Jao; Cherno Jaye; Joseph C. Woicik; Daniel A. Fischer;
Title: Enhancement of Engine Oil Wear and Friction Control Performance Through Titanium Additive Chemistry
Published: February 27, 2007
Abstract: Traditionally, wear protection and friction modification by engine oil are provided by zinc dithiophosphate (ZDDP) or other phosphorus compounds. These additives provide effective wear protection and friction control on engine parts through formation of a glassy polyphosphate antiwear film. However, the deposition of phosphorus species on automotive catalytic converters from lubricants has been known for some time to have a detrimental effect of poisoning the catalysts. To mitigate the situation, the industry has been making every effort to find ZDDP-replacement additives that are friendly to catalysts. Toward this goal we have investigated a titanium additive chemistry as a ZDDP replacement. Fully formulated engine oils incorporating this additive component have been found to be effective in reducing wear and controlling friction in a 4-ball bench wear, Sequence IIIG and Sequence IVA engine tests. Surface analysis of the tested parts by Auger electron spectroscopy, secondary ion mass spectrometry (SIMS), and X-Ray photoelectron spectroscopy (XPS) have shown that Ti species have been incorporated into the wear tracks and can only be found on the wear tracks. We used synchrotron based Near Edge X-ray Absorption Fine Structure (NEXAFS) to investigate the chemical bonding mechanism of the Ti additive with the metal surface that affects the wear improvement mechanism. We postulate that Ti provides antiwear enhancement through inclusion in the metal/metal oxide structure of the ferrous surface by forming Fe2TiO3.
Conference: Society of Tribologists & Lubrication Engineers (STLE) Proceedings
Proceedings: STLE Annual Meeting & Exhibition | 62nd| | STLE
Dates: May 6-10, 2007
Keywords: antiwear;barrier films;EXAFS;friction modifying;titanium
Research Areas: Characterization, Ceramics