TY - CONF A1 - Gradt, Thomas T1 - MoS2-Coatings for support elements in the Wendelstein 7-X nuclear fusion experiment N2 - The magnetic plasma confinement system of the nuclear fusion experiment “Wendelstein 7-X”, which recently produced the first plasma, consists of 20 planar and 50 non-planar superconducting coils. To keep them precisely in position, these coils contact each other at special support elements. The supports are operated in high vacuum at a temperature of about 4 K, and when the magnetic field is ramped up, forces up to 1500 kN and sliding motion of some mm occurs. Because mechanical disturbances may cause severe failures, only low friction without any stick-slip behaviour is tolerable. In pre-tests a PVD-MoS2-coating had proven to be the optimum solution. It was tested with downsized samples in reciprocating motion in liquid nitrogen (T = 77 K) and liquid helium (T = 4,2 K). In long-term tests in liquid nitrogen this coating showed stable sliding for up to 14.900 friction cycles without coating failure. However, in liquid helium an unexpected stick-slip effect occurred, whose origin could not be clarified so far. T2 - BAM Kolloquium Abteilung Werkstofftechnik CY - Berlin, Germany DA - 09.06.2016 KW - Kernfusion KW - Magnetischer Einschluss KW - Supraleitende Magnete KW - Tribologie KW - Festschmierstoffe KW - Magnetic confinement KW - Tribology KW - Lubricants KW - Superconducting magnet KW - Nuclear fusion PY - 2016 AN - OPUS4-38140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -