Direct Observation of Tribochemically Assisted Wear on Diamond-Like Carbon Thin Films

作者：M'ndange Pfupfu A; Ciston J; Eryilmaz O; Erdemir A; Marks L D^*

来源：Tribology Letters, 2013, 49(2): 351-356.

DOI：10.1007/s11249-012-0074-x

• Nanotribology
• Friction mechanisms
• Wear mechanisms
• Corrosive wear
• Solid lubrication mechanisms
• TEM
• EELS

Friction represents a major energy wastage, with typical estimates in the range of 2-5 % of the GDP of developed countries; 15 % of the energy losses in a new automobile engine are due to friction (Uchida et al. J. Cryst. Growth 114:565-568, 1991). While the macroscopic laws of friction have been known for centuries, the exact nanoscale processes taking place are less clear. It is established that friction involves small asperities sliding on a locally flat surface, but the exact mechanisms of slip as well as energy dissipation are still unclear and sometimes controversial. In many ways even less is known about chemical reactions occurring during sliding, what is called tribochemistry. We report here direct in situ observation at the nanoscale of tribochemically assisted wear for a tungsten tip sliding on diamond-like carbon films in wet hydrogen, nitrogen and compare these to similar experiments in vacuum. Differences in the wear directly indicate passivation of the films in hydrogen and accelerated wear in wet nitrogen. The results are surprisingly similar to what one would expect at the macroscale, indicating that in many respects there is little difference between the processes taking place across many length scales.

• 出版日期2013-2
• 单位西北大学