Viscoplastic Properties and Tribological Behavior of Diamond-Like Carbon Films Using Nanoindentation and Nanoscratch Tests

TL;DR

This study investigates the viscoplastic and tribological properties of diamond-like carbon films using nanoindentation and nanoscratch tests, revealing how environmental factors influence their friction and wear behaviors.

Contribution

It provides new insights into the relationship between viscoplasticity and tribological performance of DLC films through experimental nanoindentation and nanoscratch testing.

Findings

Tribological behavior varies significantly with environment and hydrogen content.

Viscoplastic properties correlate with low-friction and wear resistance.

Ambient air testing reveals specific mechanical characteristics of DLC films.

Abstract

Diamond-Like Carbon (DLC) films have been shown to demonstrate various tribological behaviors: in ultra-high vacuum (UHV), with either friction coefficients as low as 0.01 or less and very mild wear, or very high friction coefficients (>0.4) and drastic wear. These behaviors depend notably on gaseous environment, hydrogen content of the film [1], and on its viscoplastic properties [2,3]. A relation between superlow friction in UHV and viscoplasticity has indeed been established for a-C:H films and confirmed for a fluorinated sample (a-C:F:H). In this study, nanoindentation and nanoscratch tests were conducted in ambient air, using a nanoindentation apparatus, in order to evaluate tribological behaviors, as well as mechanical and viscoplastic properties of different amorphous carbon films.