AVS 58th Annual International Symposium and Exhibition
    Tribology Focus Topic Thursday Sessions
       Session TR-ThP

Paper TR-ThP9
Shear-induced Tribofilm Formation: Boron Containing Molecules on Copper

Thursday, November 3, 2011, 6:00 pm, Room East Exhibit Hall

Session: Tribology Focus Topic Poster Session
Presenter: Brendan Miller, University of Wisconsin Milwaukee
Authors: B.P. Miller, University of Wisconsin Milwaukee
O.J. Furlong, University of Wisconsin Milwaukee
W.T. Tysoe, University of Wisconsin Milwaukee
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The push for greener lubricants has steered focus away from compounds containing sulfur and phosphorus. The tribological chemistry can depend critically on the nature of the substrate so that a good lubricant additive for one type of surface may not be applicable to another. In particular, the lubrication of sliding copper-copper interfaces in electrical motors provides a challenge due to the requirement for a conducting interface. Boron containing molecules have been proposed as potential green lubricants since environmentally safe boric acid is a prominent decomposition product in the presence of water. The following investigates the chemistry and frictional properties of alkoxy dioxaborolane (borolane) on copper surfaces in ultrahigh vacuum (UHV) to determine the precursor at room temperature that can potentially form a tribofilm needed for the lubrication of sliding copper-copper contacts. Temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS) experiments provide the background information for investigating the frictional properties of borolane. A sliding copper-copper interface is exposed to borolane under UHV conditions, and a significant reduction in friction is found from the clean-surface values. A lasting tribofilm persisted even after the borolane dosing was stopped, and carbon was found on and below the surface in the wear scar region by in-situ Auger spectroscopy. Because the interfacial temperature rise under the experimental conditions used to measure friction is <1 K, the tribofilm formation is shear- and not thermal-induced