| AVS 54th International Symposium | |
| Tribology | Friday Sessions |
| Session TR4+SE-FrM |
| Session: | Friction and Wear of Engineered Surfaces Macro- to Nanoscale Approaches |
| Presenter: | C.C. Baker, Naval Research Laboratory |
| Authors: | C.C. Baker, Naval Research Laboratory N.D. Theodore, Naval Research Laboratory T. Feygelson, GeoCenters Incorporated J.E. Butler, Naval Research Laboratory K.J. Wahl, Naval Research Laboratory |
| Correspondent: | Click to Email |
The tribological behavior of nanocrystalline diamond (NCD) coatings was studied under both unidirectional and reciprocating sliding conditions. Coatings were deposited by microwave plasma chemical vapor deposition onto Si substrates under varying growth conditions to thicknesses between 1-2 microns. Friction behavior was investigated using pin-on-flat geometry with sapphire counterfaces at average contact pressures of 0.43-0.74 GPa. Wear volumes of the ball counterface and coating wear tracks were determined with optical interferometry. Coating microstructure, chemistry, and surface morphology were examined using X-ray diffraction (XRD), micro-Raman spectroscopy, and atomic force microscopy (AFM). We have found that friction coefficients for the sapphire-NCD sliding interface are low, ranging from 0.03 to 0.1. However, there were large differences in friction run-in, with run-in from high to low friction taking between 50 to as many as 10000 cycles over a wide range of NCD deposition conditions. The role of coating microstructure, bonding chemistry, wear, and roughness of worn and unworn surfaces on run-in friction behavior of NCD will be discussed.