Surface Chemistry and Tribology of Carbide and Nitride Hard Coatings

摘要

Work on the contract F49620-97-C-0029 was completed by 1/15/2000. During this reporting period, the research teams at the University of Houston and The Aerospace Corporation investigated the surface chemical interaction of a number of molecular adsorbates with the (100) face of titanium carbide and vanadium carbide using an array of surface analytical measurement tools. Adsorbates included oxygen and water, considered important from an environmental 'aging' perspective, carbon monoxide and ammonia as probes of the electronic structure model developed within this program, and a series of alcohols including methanol, ethanol, trifluoroethanol, isopropanol, and methyl allyl alcohol as probes of interfacial reactivity. An array of surface analytical techniques producing independent yet complimentary data were employed to develop a complete chemical and structural picture of the adsorption and reaction of these molecular adsorbates. In addition to demonstrating unique reactivities for the different classes of adsorbates, these studies revealed substrate-dependent reactivities. From a tribological perspective, we demonstrated the inherent difference in the frictional properties of stoichiometric TiC, VC, and titanium nitride with atomic force microscopy in both ambient and vacuum environments, thus allowing for the future design of advanced tribological counterfaces.