Lubricious Silver Tantalate Films for Extreme Temperature ApplicationsSurface and Coatings Technology
AbstractSilver tantalate was investigated as a potential lubricious material for moving assemblies in high temperature tribological applications. Three different approaches were explored for the creation of such materials on Inconel substrates: (1) powders produced using a solid state which were burnished on the surface; (2) monolithic silver tantalate thin films deposited by magnetron sputtering; and, (3) an adaptive tantalum nitride/silver nanocomposite sputter-deposited coating that forms a lubricious silver tantalate oxide on its surface when operated at elevated temperatures. Dry sliding wear tests of the coatings against Si3N4 counterfaces revealed friction coefficients in the 0.06–0.15 range at T ~ 750 °C. Reduced friction coefficients were found in nanocomposite materials that contained primarily a AgTaO3 phase with a small amount of segregated Ag phase, as suggested by structural characterization using X-ray diffraction. Furthermore, cross-sectional transmission electron microscopy techniques determined that the reduced coefficient of friction at T ~ 750 °C was primarily the result of the formation of a lubricious AgTaO3 phase that reconstructs during the wear process into a mechanically mixed layer of AgTaO3, Ta2O5, and Ag nanoparticles.
CopyrightCopyright © 2013, Elsevier
Citation InformationD. S. Stone, S. Harbin, Hamidreza Mohseni, Jon E. Mogonye, et al.. "Lubricious Silver Tantalate Films for Extreme Temperature Applications" Surface and Coatings Technology Vol. 217 Iss. 25 (2013)
Available at: http://works.bepress.com/christopher-muratore/59/