Berlin 2015 – scientific programme

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O: Fachverband Oberflächenphysik

O 31: Tribology

O 31.6: Talk

Tuesday, March 17, 2015, 15:15–15:30, MA 144

Contact Ageing observed during Stick Slip Movement of Antimony Nanoparticles — Michael Feldmann, •Dirk Dietzel, and Andre Schirmeisen — Justus Liebig University, Giessen, Germany

Contact ageing is an essential process to understand macro-scale friction dynamics and is typically related to an increasing contact area of asperities. It is less clear, however, if nanoscale asperities of constant size are also capable of ageing. Only recently, such contact ageing was demonstrated for antimony nanoparticles sliding on HOPG [1]. From temperature and velocity dependent measurements, a thermally activated contact ageing of the interface was deduced, while, at the same time, an increase of contact area can be ruled out. Additional measurements with a high data acquisition rate have now revealed that particle movement follows a stick slip pattern as it is common in friction force microscopy. By regarding the slip events as recurring contact renewal, the age of the contact can directly be related to the stick phases. This allows for a very direct assessment of contact ageing and a logarithmic increase of friction with the age of contact is found.

[1] Feldmann, Dietzel, Fuchs, Schirmeisen, Phys. Rev. Lett. 112, 155503 (2014)