Predicting the Hydrogen Pressure to Achieve Ultralow Friction and Diamondlike Carbon Surfaces from First Principles

Author(s)

Haibo Guo
Yue Qi
Xiaodong Li, University of South Carolina - ColumbiaFollow

Document Type

Article

Abstract

Hydrogen atmosphere can significantly change the tribological behavior at diamond and diamondlike carbon (DLC) surfaces and the friction-reducing effect depends on the partial pressure of hydrogen. We combined density functional theory modeling and thermodynamic quantities to predict the equilibrium partial pressures of hydrogen at temperature T, P_H2 (T), for a fully atomic hydrogen passivated diamondsurface. Above the equilibrium P_H2 (T), ultralow friction can be achieved at diamond and DLC surfaces. The calculation agrees well with friction tests at various testing conditions. We also show that P_H2 (T) increases with temperature; therefore, the temperature effect observed in friction tests should first be treated as an equilibrium factor rather than a kinetic factor.

Publication Info

Published in Applied Physics Letters, Volume 92, Issue 24, 2008, pages #241921-.

Rights

©Applied Physics Letters 2008, American Institute of Physics.

• Guo, H., Qi, Y., & Li, X. (16 June 2008). Predicting the Hydrogen Pressure to Achieve Ultralow Friction and Diamondlike Carbon Surfaces from First Principles. Applied Physics Letters, 92 (24), #241921. http://dx.doi.org/10.1063/1.2946661