Novel In Situ Molecular Lubrication Strategies for Controlling Friction, Wear, and ContaminationPublic Deposited
Most lubricants contain a series of additives that reduce friction and wear, and protect contacting surfaces. The design of these additives must be modernized to meet the challenges involved with high operating temperatures, extreme environmental conditions, and increasingly stringent environmental regulations. This research demonstrates three novel lubricant additive strategies that have been developed and tested in order to address contemporary tribological demands. The additives are molecularly engineered to undergo a specific set of chemical reactions in situ, or within the tribological environment, producing a reactant material that is beneficial to lubrication. The findings are a result of a collaborative effort from experts in mechanical engineering, chemistry, and materials science. The first additive is an organosilver molecule that breaks down at high temperatures, depositing lubricious metallic silver on contacting surfaces. The additive successfully maintained lubricity at high temperatures, after the lubricating fluids thermally failed. The next is an organosilane molecule that reacts with external contaminants in the lubricant, successfully reducing contaminant particle agglomeration and mitigating wear. The additive was specially designed, and its interaction with silica was analyzed. Then, the additive successfully reduced spikes in friction and wear due to sand contamination. The final additive is a precursor molecule for carbon tribofilms, which breaks down to during contact to form lubricious graphitic carbon near contacting surfaces. Friction and wear were greatly reduced under a variety of conditions because of the lubricious carbon tribofilms.