AVS 58th Annual International Symposium and Exhibition
    Tribology Focus Topic Thursday Sessions
       Session TR+AS+SS-ThM

Paper TR+AS+SS-ThM6
Molecular Dynamics Simulations of Contact between Carbon-Based Materials: Isolating the Effects of Experimental Variables

Thursday, November 3, 2011, 9:40 am, Room 111

Session: Atomic-scale Characterization of Tribological Interfaces
Presenter: Judith Harrison, US Naval Academy
Authors: J.A. Harrison, US Naval Academy
K.E. Ryan, US Naval Academy
P.L. Keating, US Naval Academy
D.S. Grierson, University of Wisconsin Madison
J. Liu, University of Wisconsin Madison
K.T. Turner, University of Wisconsin Madison
R.W. Carpick, University of Pennsylvania
Correspondent: Click to Email
The behavior of nanoscale contacts is complex and often cannot be understood through continuum mechanics alone. Here, parallel molecular dynamics (MD) simulations using the AIREBO potential for hydrocarbons to model indentation and friction, are used to investigate nanoscale contacts of carbon-based materials, such as diamond, DLC, and ultrananocrystalline diamond (UNCD). Specifically, the contact of carbon-based AFM probes is simulated to understand the effects of experimental parameters, including tip geometry and material selection, on the adhesion between the tip and sample. Results from the MD simulations will be compared to and discussed within the context of the complementary atomic force microscope experiments and finite element simulations. The tribological response of carbon-based materials is very sensitive to environmental conditions. For example, the presence of water has been shown to negatively impact the friction performance of hydrogenated DLCs but to improve the performance of nanocrystalline and ultrananocrystaline diamond. We have been working to develop a potential energy function that is capable of modeling carbon-based materials in the presence of water. This talk will also outline our current efforts at potential development.