Molecular dynamics simulations of dissolved hydrogen molecules under shear condition

Dissolved gas components in lubricating films often affect tribological properties, e.g., a friction force and fatigue life. Molecular dynamics simulations were performed to investigate the behaviors of dissolved hydrogen molecules in lubricating film under high pressure and shear. Change in percentage of hydrogen adatoms with time was put forward. When the lubricant was sheared, the diffusion of dissolved hydrogen molecules in lubricants was induced, and the number of hydrogen molecules adsorbed on the solid surface increases. The OPLS-AA force field was used to describe the interacting forces among lubricant molecules. The diffusion of hydrogen molecules were affected by pressure, temperature. shear rate, and lubricant molecular structure. This is an abstract of a paper presented at the 2009 World Tribology Congress (Kyoto, Japan 9/6-11/2009).