TY - JOUR A1 - Schneider, Thomas A1 - Vierneusel, B. A1 - Gradt, Thomas A1 - Tremmel, S. A1 - Wartzack, S. A1 - Szücs, Z. A1 - Arendt, I. T1 - Optimierte MoS2-PVD-Schichten für wechselnde Umgebungsbedingungen N2 - Der Festschmierstoff Molybdändisulfid ist insbesondere für Extremanwendungen ein gerne eingesetzter Werkstoff, problematisch ist jedoch der negative Einfluss von Feuchtigkeit. Bei mittels PVD-Verfahren abgeschiedenen MoS2-Schichten ergibt sich jedoch die Möglichkeit, durch Anpassung der Beschichtungsparameter vorwiegend basal ausgerichtete Schichten herzustellen, die auch an Luft ein verbessertes tribologisches Verhalten zeigen. N2 - The solid lubricant molybdenum disulfide is a well known material for extreme conditions, but Problems arise due to a negative effect of humidity. However, by using a PVD process, deposition parameters can be optimized to gain coatings with a more textured structure orienting the basal planes parallel to the Substrate surface. Therefore, an improved tribological behavior even under moist conditions can be achievcd. KW - MoS2-coatings KW - PVD-process KW - Tribology KW - Moisture KW - Cryogenic temperatures KW - MoS2-Beschichtungen KW - PVD KW - Tribologie KW - Luftfeuchte KW - Kryogene Temperaturen PY - 2013 SN - 0724-3472 VL - 60 IS - 4 SP - 18 EP - 23 PB - Expert Verlag CY - Renningen AN - OPUS4-29995 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Thomas A1 - Gradt, Thomas A1 - Vierneusel, B. A1 - Tremmel, S. A1 - Wartzack, S. T1 - Tribological behavior of MoS2 in hydrogen environment N2 - The solid lubricant molybdenum disulfide is a well known material for extreme conditions where conventional oil or grease lubrication is not feasible (vacuum, high pressures). However, under reactive environments e.g. high humidity or hydrogen MoS2 is prone to premature failure. By using a PVD process, deposition parameters can be optimized to gain coatings with a more textured structure orienting the basal planes parallel to the Substrate surface, A similar concept has been used by Koch et al. for coatings developed to withstand the extreme operational conditions of the WENDELSTEIN W7-X fusion experiment. Therefore, an improved tribological behavior even under adverse conditions can be achieved. T2 - WTC 2013 - 5th World tribology congress CY - Torino, Italy DA - 08.09.2013 KW - Tribologie KW - Festschmierstoffe KW - MoS2 KW - Wasserstofftechnologie PY - 2013 SP - 1 EP - 3 AN - OPUS4-31156 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vierneusel, B. A1 - Schneider, Thomas A1 - Tremmel, S. A1 - Wartzack, S. A1 - Gradt, Thomas T1 - Humidity resistant MoS2 coatings deposited by unbalanced magnetron sputtering N2 - MoS2 is a suitable solid lubricant for environments free of oxygen or water vapor (i.e. vacuum). Humid air degrades film properties due to oxidation accompanied by high wear and increasing coefficients of friction. The present study aims at the further development of sputtered pure MoS2 coatings, extending their applicability to varying environmental conditions by increasing the resistance against humidity. The systematic coating development process is supported by using an experimental Box–Behnken design with variations of the deposition parameters cathode voltage, target/substrate distance, temperature and argon gas pressure. In contrast to common one-factor-at-a-time (OFAT) studies, this approach enables a determination of interactions between deposition process parameters and tribological–mechanical MoS2 film properties. The tribological improvement focuses on a maximization of wear resistance in air and vacuum measured in ball-on-disk experiments. The evaluated mechanical properties are hardness, elastic modulus and residual stresses. These stresses were determined by the substrate curvature method. The study reveals that the residual stress state in the films and the hardness-to-modulus ratio are crucial for their tribological performance in humid air and vacuum environments. After a detailed determination of the relationships between deposition conditions and film properties, some selected microstructural analyses are presented which show that a substantially basal orientation of the lattice has positive effects on wear but also causes anisotropic film properties which result in fissile fracture of the coating if strong shock or point loads occur. KW - Unbalanced magnetron sputtering KW - MoS2 KW - Humidity resistance KW - Residual stress PY - 2013 DO - https://doi.org/10.1016/j.surfcoat.2013.07.019 SN - 0257-8972 VL - 235 SP - 97 EP - 107 PB - Elsevier B.V. AN - OPUS4-29729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Thomas A1 - Vierneusel, B. A1 - Gradt, Thomas A1 - Tremmel, S. A1 - Wartzack, S. A1 - Szücs, Z. A1 - Arendt, I. T1 - Optimierte MoS2-PVD-Schichten für wechselnde Umgebungsbedingungen N2 - Der Festschmierstoff Molybdändisulfid ist insbesondere für Extremanwendungen, bei denen konventionelle Öl- oder Fettschmierung nicht in Frage kommen (Vakuum, hohe Pressungen) ein gerne eingesetzter Werkstoff. Problematisch ist jedoch der negative Einfluss von Feuchtigkeit, wodurch die Einsetzbarkeit von M0S2 unter Normalbedingungen leidet. Bei mittels PVD-Verfahren abgeschiedenen MoSa-Schichten ergibt sich jedoch die Möglichkeit, durch Anpassung der Beschichtungsparameter vorwiegend basal ausgerichtete Schichten herzustellen, die auch an normal feuchter Luft ein verbessertes tribologisches Verhalten zeigen. MoSa-Schichten sind darüber hinaus auch für Anwendungen bei extrem tiefen Temperaturen interessant, da hier kein Schmierstoff zur Verfügung steht, der ähnlich günstige Reibeigenschaften aufweist. Für bewegliche Stützelemente zwischen supraleitenden Magnetspulen des Kernfusions-Experiments Wendelstein 7-X waren bis zu 7 pm dicke Schichten entwickelt worden, die jedoch durch das notwendige langsame Aufwachsen für andere Anwendungen nicht wirtschaftlich herzustellen waren. Hier sollen neue, im Rahmen eines Kooperationsprojekts entstandene MoS2-PVD-Schichten vorgestellt werden, die bei wechselnden Umgebungsbedingungen noch gute tribologische Eigenschaften liefern, jedoch durch ihre Dicke von 1-2 pm und hoher Aufwachsrate kostengünstig sind. N2 - The solid lubricant molybdenum disulfide is a well known material for extreme conditions where conventlonal oll or grease lubrication is not feasible (vacuum, high pressures). Problems arise due to a negative effect of humidity which is a drawback for the suitability of M0S2 under normal conditions. However, by using a PVD process, Deposition parameters can be optimized to gain coatings with a more textured structure orienting the basal planes parallel to the Substrate surface. Therefore, an improved tribological behavior even under moist conditions can be achieved. MoS2-coatings additionally are interesting candidates for being applied under cryogenic temperatures, since no lubricant is available having similarly favorable frictional properties. Up to 7 pm thick coatings have been developed especially for sliding support elements between superconducting magnets of the fusion-experiment Wendelstein 7-X, however, the extremely slow deposition rate precluded its utilization on more common tribo-systems due to cost considerations. Here, new MoS2-coatings are presented which were developed in a cooperational project, giving good tribological results under variing environments but are more cost effective being only 1-2 pm in thickness and faster in film growth.. T2 - 53. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß CY - Göttingen, Germany DA - 24.09.2012 PY - 2012 SN - 978-3-00-039201-6 SP - 46/1 EP - 46/12 CY - Aachen AN - OPUS4-26724 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -