TY - CONF A1 - Spaltmann, Dirk A1 - Manier, Charles-Alix A1 - Theiler, Geraldine A1 - Proß, E. A1 - Ziegele, H. A1 - Kursawe, S. A1 - Woydt, Mathias T1 - Überrollbeständige Dünnschichten unter geschmierter Wälzreibung bis 3.500 MPa T2 - 49. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß - Forschung und praktische Anwendungen CY - Göttingen, Deutschland DA - 2008-09-22 KW - Thin film coating KW - Slip-rolling KW - DLC KW - ta-C KW - Zr(C,N) PY - 2008 SN - 978-3-00-025676-9 VL - I SP - 2/1 EP - 2/16 AN - OPUS4-31750 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manier, Charles-Alix A1 - Theiler, Geraldine A1 - Spaltmann, Dirk A1 - Woydt, Mathias A1 - Ziegele, H. T1 - Benchmark of thin film coatings for lubricated slip-rolling contacts N2 - The light-weight approach and fuel economy targets in today's automotive engineering require tribosystems, which can withstand higher contact pressures associated with low coefficients of friction. The application of high-performance coatings represents one approach among others. This paper presents some recently developed DLC coatings (a-C:H and ta-C) as well as a novel coating-substrate system (Zr(C,N)) in a benchmark test procedure under slip-rolling conditions in the presence of liquid lubricants. Various coatings with different thickness, interlayer and substrates were evaluated for their slip-rolling resistance in different lubricants at ambient temperature and at 120 °C. Results indicate that some of these coating systems can withstand at least 10 million cycles under initial Hertzian contact pressures of up to Pmax = 3.500 MPa and oil temperatures of at least 120 °C associated with low coefficients of friction under mixed/boundary conditions. Surface of the coatings and the counter bodies were analysed and compared with untreated substrates. KW - Slip-rolling KW - DLC KW - Thin film coating KW - Zr(C,N) KW - Polyglycol PY - 2010 DO - https://doi.org/10.1016/j.wear.2010.02.020 SN - 0043-1648 VL - 268 IS - 11-12 SP - 1442 EP - 1454 PB - Elsevier CY - Amsterdam AN - OPUS4-21196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pimentel, A. S. O. A1 - Guesser, W. L. A1 - Portella, Pedro Dolabella A1 - Woydt, Mathias A1 - Burbank, J. T1 - Slip-rolling behavior of ductile and austempered ductile iron containing niobium or chromium N2 - The use of high niobium alloyed cast iron alloys is a relatively new approach in which the niobium addition intends to improve the properties of the material by the precipitation of hard niobium carbides during solidification. Steels can be replaced by ductile cast iron in some rolling applications, such as gears and cams, in order to reduce material costs. The aim of this work is to evaluate ductile iron alloyed with 1 weight percent (wt.%) niobium for the as cast specimens and with 1.8 wt.% and 2.4 wt.% niobium for the austempered specimens under lubricated slip-rolling tests using mixed/boundary conditions in an Amsler-type machine. Austempered ductile iron (ADI) alloyed with 1 wt.% chromium, or Carbidic ADI, was tested for comparison. For the as cast conditions, the niobium addition resulted in an increase of wear resistance owing to the low contact pressure of these tests. However, for the austempered specimens, the best performance was found for unalloyed ADI. The main factor acting in the initiation and propagation of cracks in ductile iron is the presence of the graphite nodules. The coarse carbides also contributed to the initiation of cracks and spalling of the material. KW - Ductile iron KW - Niobium alloying KW - Slip-rolling KW - Carbidic austempered ductile iron PY - 2019 DO - https://doi.org/10.1520/MPC20180188 SN - 2165-3992 SN - 2379-1365 VL - 8 IS - 1 SP - 402 EP - 418 PB - ASTM International CY - West Conshohocken, Pa. AN - OPUS4-51209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -