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Proposing Institution

Otto Schott Institut für Materialwissenschften , Friedrich Schiller Universität Jena
Project Manager

Prof. Dr. Enrico Gnecco
Löbdergraben 32
07743 Jena
One of the most relevant scientific advances in tribology was the observation that sliding friction usually occurs in a sequence of disruptive stick-slip events, where the latter is the one responsible for dissipating the mechanical energy accumulated in the contact. With regard to the stick phase, it has been shown that it strengthens with time. This time strengthening of the contact is known as contact aging. So far, experiments coupled with analytical models have provided us valuable insights in order to understand how this process occurs at the nanoscale. Although recent works seem to indicate that this process might be governed (in some cases) by diffusion of atoms in the contact, little is known about the atomistic detail of this process. This kind of description is pivotal to provide a unified understanding of contact aging mechanism, e.g. to understand the resemblance and differences of contact aging between metals and insulating materials like alkali halides and oxides. In this work, we aim to simulate aging in nanocontacts formed by a tip (representing a single nanoasperity in a real contact) and a substrate, to explore the influence of the materials forming the tip and sample and how the contact aging of these materials depends on the temperature. We shall considered three representative substrates: crystalline KBr and NaCl surfaces, and amorphous SiO2. The atomically detailed molecular dynamics description of the contact aging in these materials shall enlighten our understanding of this complex process and pave the way to an improvement for current models of aging.

Impressum, Conny Wendler