AVS 60th International Symposium and Exhibition
    Tribology Focus Topic Tuesday Sessions
       Session TR+SE-TuM

Paper TR+SE-TuM12
Scaling of Structural Lubricity

Tuesday, October 29, 2013, 11:40 am, Room 203 C

Session: Low Friction Materials
Presenter: A. Schirmeisen, University of Giessen, Germany
Authors: D. Dietzel, University of Giessen, Germany
M. Feldmann, University of Giessen, Germany
U.D. Schwarz, Yale University
H. Fuchs, University of Muenster, Germany
A. Schirmeisen, University of Giessen, Germany
Correspondent: Click to Email
In an effort to reduce the friction between sliding components scientists and engineers have developed a multitude of lubrication schemes. One of the most intriguing concepts is referred to as `structural lubricity', where at surfaces are thought to slide past each other virtually frictionless if their atomic structures are incommensurate, i.e. they do not match. Corresponding theories are based on sub-linear power laws for the area-dependence of friction in the structural lubricity regime, but this unusual scaling has never been observed so far. Here, we present experiments that quantify nanoparticle sliding resistance of amorphous antimony particles on crystalline graphite [1,2]. Our results confirm the predicted sub-linear scaling behavior for incommensurate, disordered interfaces, and allow a direct link between mesoscopic friction and atomic principles. Additionally, the case of crystalline incommensurate interfaces is investigated for gold crystals on graphite, pointing towards a more complex scaling behavior that accounts for particle shape and orientation. Our findings point towards a new route to engineer surfaces with unprecedented low friction on the basis of well-defined nanocontacts.

[1] A. Schirmeisen and U. D. Schwarz, ChemPhysChem 10 (2009) 2358

[2] D. Dietzel et al., Physical Review Letters 101 (2008) 125505