Abstract

In humid air and dry nitrogen, as-deposited, fine-grain diamond films and polished, coarse-grain diamond films have low steady-state coefficients of friction (<0.1) and low wear rates (≤10⁻⁶ mm³/N-m). In an ultrahigh vacuum (10⁻⁷ Pa), however, they have high steady-state coefficients of friction (>0.6) and high wear rates (≥10⁻⁴ mm³/N-m). Therefore, the use of as-deposited, fine-grain and polished, coarse-grain diamond films as wear-resistant, self-lubricating coatings must be limited to normal air or gaseous environments such as dry nitrogen. On the other hand, carbon-ion-implanted, fine-grain diamond films and nitrogen-ion-implanted, coarse-grain diamond films have low steady-state coefficients of friction (<0.1) and low wear rates (≤10⁻⁶ mm³/N-m) in all three environments. These films can be effectively used as wear-resistant, self-lubricating coatings in an ultrahigh vacuum as well as in normal air and dry nitrogen.

© 1995 Optical Society of America