Superlow Friction Behavior of Diamond-Like Carbon Coatings: Time and Speed Effects
Abstract
The friction behavior of a diamond-like carbon coating was studied in reciprocating sliding contact at speeds from 0.01 to 5 mm/s, in dry nitrogen. "Superlow" friction coefficients of 0.003 0.008 were obtained in continuous sliding at the higher speeds (>1 mm/s). However, friction coefficients rose to values typical of diamond-like carbon in dry and ambient air (0.01-0.1) at lower speeds (<0.5 mm/s) as well as in time-delayed, higher speed tests. The rise of the friction coefficients in both speed and time-delay tests was in good quantitative agreement with gas adsorption kinetics predicted by the Elovich equation for adsorption onto carbon. More generally, superlow friction could be sustained, suppressed, and recovered as a function of exposure time, demonstrating that duty cycle cannot be ignored when predicting performance of superlow friction coatings in devices.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 23, 2001
- Accession Number
- ADA465025
Entities
People
- A. Erdemir
- I. L. Singer
- J. A. Heimberg
- K. J. Wahl
Organizations
- United States Naval Research Laboratory