Nanoscale Indentation Hardness and Wear Characterization of Hydrogenated Carbon Thin Films

[+] Author and Article Information
B. Wei, K. Komvopoulos

Department of Mechanical Engineering, University of California, Berkeley, CA 94720

J. Tribol 117(4), 594-601 (Oct 01, 1995) (8 pages) doi:10.1115/1.2831521 History: Received June 02, 1994; Revised December 16, 1994; Online January 24, 2008


An experimental investigation of the surface topography, nanoindentation hardness, and nanowear characteristics of carbon thin films was conducted using atomic force and point contact microscopy. Hydrogenated carbon films of thickness 5, 10, and 25 nm were synthesized using a sputtering technique. Atomic force microscopy images obtained with silicon nitride tips of nominal radius less than 20 nm demonstrated that the carbon films possessed very similar surface topographies and root-mean-square roughness values in the range of 0.7–1.1 nm. Nanoindentation and nanowear experiments performed with diamond tips of radius equal to about 20 nm revealed a significant enhancement of the hardness and wear resistance with increasing film thickness. High-resolution surface imaging indicated that plastic flow was the dominant deformation process in the nanoindentation experiments. The carbon wear behavior was strongly influenced by variations in the film thickness, normal load, and number of scanning cycles. For a given film thickness, increasing the load caused the transition from an atomic-scale wear process, characterized by asperity deformation and fracture, to severe wear consisting of plowing and cutting of the carbon films. Both the critical load and scanning time for severe wear increased with film thickness. Below the critical load, the wear rate decreased with further scanning and the amount of material worn off was negligibly small, while above the critical load the wear rate increased significantly resulting in the rapid removal of carbon. The observed behavior and trends are in good qualitative agreement with the results of other experimental and contact mechanics studies.

Copyright © 1995 by The American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.





Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In