# How Tribo-Oxidation Alters the Tribological Properties of Copper and Its Oxides [in press]

Lehmann, J. S.; Schwaiger, R.; Rinke, M.; Greiner, C.

##### Abstract:
Tribochemical reactions in many applications determine the performance and lifetime of individual parts or entire engineering systems. The underlying processes are however not yet fully understood. Here, the tribological properties of copper and its oxides are investigated under mild tribological loading and for dry sliding. The oxides represent the late stages of a copper–sapphire tribo‐contact, once the whole copper surface is covered with an oxide. For this purpose, high‐purity copper, thermally‐oxidized and sintered Cu$_{2}$O and CuO samples are tribologically loaded and eventually formed wear particles analyzed. The tribological behavior of the oxides is found to be beneficial for a reduction of the coefficient of friction (COF), mainly due to an increase in hardness. The results reveal tribochemical reactions when copper oxides are present, irrespective of whether they form during sliding or are existent from the beginning. Most strikingly, a reduction of copper oxide to metallic copper is observed in X‐ray photoelectron spectroscopy measurements. A more accurate understanding of tribo‐oxidation will allow for manufacturing well‐defined surfaces with enhanced tribological properties. ... mehr

 Zugehörige Institution(en) am KIT Institut für Angewandte Materialien - Computational Materials Science (IAM-CMS) Publikationstyp Zeitschriftenaufsatz Publikationsjahr 2020 Sprache Englisch Identifikator ISSN: 2196-7350 KITopen-ID: 1000127684 Erschienen in Advanced materials interfaces Verlag Wiley Seiten Art.-Nr.: 2001673 Vorab online veröffentlicht am 16.11.2020 Nachgewiesen in ScopusWeb of Science
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