TY - JOUR 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 KW - DLC KW - Kohlenstoff Wälzen KW - Schlupf KW - Schmierung KW - Temperatur KW - Pressung PY - 2008 SN - 0724-3472 VL - 55 IS - 4 SP - 22 EP - 27 PB - Expert Verlag CY - Renningen AN - OPUS4-18029 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - GEN A1 - Klein, P. A1 - Zhang, Z. A1 - Friedrich, K. A1 - Theiler, Geraldine A1 - Hübner, Wolfgang T1 - Zur Bildung von Transferfilmen bei ausgewählten PTFE-Compounds T2 - Tribologie-Fachtagung 2002 CY - Göttingen, Deutschland DA - 2002-09-23 PY - 2002 SN - 3-00-003404-8 VL - 1 SP - 8-1-8-11 PB - GfT CY - Moers AN - OPUS4-1867 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klein, P. A1 - Zhang, Z. A1 - Friedrich, K. A1 - Theiler, Géraldine A1 - Hübner, Wolfgang T1 - Zur Bildung von Transferfilmen bei ausgewählten PTFE-Compounds KW - Wear KW - Transfer film KW - Polytetrafluoroethylene KW - Composites PY - 2003 SN - 0724-3472 VL - 50 IS - 4 SP - 32 EP - 36 PB - Expert Verlag CY - Renningen AN - OPUS4-12663 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hübner, Wolfgang A1 - Gradt, Thomas A1 - Theiler, Geraldine A1 - Aßmus, Kristin A1 - Ostrovskaya, Y. T1 - Werkstoff-Untersuchungen für technische Anwendungen in flüssigem Wasserstoff T2 - 1. Deutscher Wasserstoff-Energie-Tag 2002 CY - Essen, Deutschland DA - 2002-10-12 PY - 2002 IS - CD-ROM SP - 1 EP - 8 AN - OPUS4-1973 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klein, P. A1 - Friedrich, K. A1 - Theiler, Geraldine A1 - Hübner, Wolfgang ED - Friedrich, K. ED - Hübner, W. T1 - Untersuchungen zum Verschleissverhalten ausgewählter PTPE-Werkstoffe bei Raumtemperatur T2 - 1. Symposium im DFG-Projekt 'Eigenschaften von PTFE- und PEEK-Matrix-Werkstoffen bei Tribologischer Beanspruchung' CY - Berlin, Germany DA - 2000-11-24 PY - 2001 N1 - Serientitel: BAM-Sonderheft – Series title: BAM-Sonderheft VL - 2001-3 IS - 3 SP - 13 EP - 18 PB - BAM CY - Berlin AN - OPUS4-12657 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hübner, Wolfgang A1 - Theiler, Geraldine A1 - Klein, P. A1 - Friedrich, K. T1 - Untersuchungen zum Einfluss kryogener Medien auf den Materialtransfer im Tribosystem Polymer-Komposit/Stahl T2 - Tribologie-Fachtagung 2000 CY - Göttingen, Deutschland DA - 2000-09-25 PY - 2000 SN - 3-00-003404-8 VL - 1 SP - 12-1 - 12-11 PB - Gesellschaft für Tribologie CY - Moers AN - OPUS4-12654 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Géraldine T1 - Tribology of polymers materials in hydrogen N2 - The paper deals with the tribological properties of polymers in hydrogen gas at ambient temperature as well as in liquid hydrogen (-253°C). The influence of hydrogen is discussed in relation to compositions and triboreactions. T2 - Hydrogenius and I2CNER Tribology Symposium CY - Fukuoka, Japan DA - 02.04.2016 KW - Polymers KW - Hydrogen KW - Tribology PY - 2016 AN - OPUS4-38138 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Géraldine A1 - Gradt, Thomas T1 - Tribology of polymeric materials in gaseous and liquid hydrogen N2 - This presentation gives an overview of the tribological behaviour of polymeric materials in gaseous and luquid hydrogen. T2 - HYDROGENIUS-BAM Joint Hydrogen Symposium CY - Online meeting DA - 06.07.2021 KW - Polymers KW - Hydrogen KW - Friction KW - Wear PY - 2021 AN - OPUS4-53701 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine T1 - Tribology of polymer materials in hydrogen N2 - The polymer chemical structure of the polyimide has a major influence on the tribological behaviour. The addition of graphite in PI2 has a beneficial effect in hydrogen on the friction and wear. The low friction of graphite is associated with a lubricant film in hydrogen. The influence of hydrogen on graphite is more effective than humidity. CNTs have a similar effect to that of graphite in PEEK composites. TiO2 particles improve significantly the wear rate both in vacuum and hydrogen environment. In LH2 friction and wear decrease for unfilled polymers. Friction of graphite filled composites increases slightly and wear rate is stable. T2 - 10. International Hydrogen Energy Development Forum 2016 / 2016 HYDROGENIUS & I2CNER Tribology Symposium CY - Fukuoka, Japan DA - 04.02.2016 KW - Hydrogen KW - Tribology KW - Polymer materials KW - Cryogenic temperature KW - CNT KW - TiO2 KW - PEEK PY - 2016 AN - OPUS4-35641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Géraldine A1 - Gradt, Thomas T1 - Tribology of polymer materials in cryogenic hydrogen and methane N2 - The development of hydrogen technologies is a key strategy to reduce greenhouse gas emission worldwide. Power-to-Gas is a challenging solution, in which hydrogen and methane can be used in mobility, industry, heat supply and electriity generation applications. This presentation deals with the tribological behaviour of polymer materials in hydrogen and methane, both in gas and in liquid form. T2 - 2018 HYDROGENIUS & I2CNER Tribology Symposium CY - Fukuoka, Japan DA - 02.02.2018 KW - Hydrogen KW - Methane KW - Sliding friction KW - Polymers KW - Cryogenic temperature PY - 2018 AN - OPUS4-44483 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Hübner, Wolfgang A1 - Klein, P. A1 - Friedrich, K. T1 - Tribologisches Verhalten der Werkstoffpaarung Verbundwerkstoff/Stahl bei tiefen Temperaturen - Die Rolle der Kältemittel T2 - Tribologie-Fachtagung 2003 CY - Göttingen, Germany DA - 2003-09-22 PY - 2003 AN - OPUS4-4301 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Hübner, Wolfgang A1 - Klein, P. A1 - Friedrich, K. T1 - Tribologisches Verhalten der Werkstoffpaarung Polymerverbundwerkstoff/Stahl bei tiefen Temperaturen T2 - Reibung, Schmierung und Verschleiß, 44. Tribologie-Fachtagung CY - Göttingen, Germany DA - 2003-09-22 PY - 2003 AN - OPUS4-3088 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Theiler, Geraldine A1 - Hübner, Wolfgang A1 - Klein, P. A1 - Friedrich, K. T1 - Tribologisches Verhalten der Werkstoffpaarung Polymerverbundwerkstoff/Stahl bei tiefen Temperaturen T2 - 44. Tribologie-Fachtagung CY - Göttingen, Deutschland DA - 2003-09-22 PY - 2003 SN - 3-00-003404-8 VL - 1 SP - 8-1-8-12 PB - GfT CY - Moers AN - OPUS4-2664 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Theiler, Géraldine A1 - Hübner, Wolfgang A1 - Gradt, Thomas A1 - Klein, P. A1 - Friedrich, K. T1 - Tribologisches Verhalten der Werkstoffpaarung Polymerverbundwerkstoff/Stahl bei tiefen Temperaturen KW - Kryotechnik KW - Polymerkomposite KW - PTFE KW - PEEK KW - Flüssigwasserstoff KW - Flüssighelium KW - Reibungszahlen KW - Übertrag PY - 2005 SN - 0724-3472 VL - 52 IS - 1 SP - 20 EP - 25 PB - Expert Verlag CY - Renningen AN - OPUS4-12645 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klein, P. A1 - Friedrich, K. A1 - Theiler, Geraldine A1 - Hübner, Wolfgang T1 - Tribologische Untersuchungen an PTFE-Verbundwerkstoffen für den Einsatz in kryogenen Medien T2 - Tribologie-Fachtagung 2000 CY - Göttingen, Deutschland DA - 2000-09-25 PY - 2000 SN - 3-00-003404-8 VL - 1 SP - 9-1 - 9-10 PB - Gesellschaft für Tribologie CY - Moers AN - OPUS4-12655 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Hübner, Wolfgang A1 - Klein, P. A1 - Friedrich, K. ED - Friedrich, K. ED - Hübner, W. T1 - Tribologische Eigenschaften ausgewählter PTFE-Werkstoffe bei tiefen Temperaturen T2 - 1. Symposium im DFG-Projekt 'Eigenschaften von PTFE- und PEEK-Matrix-Werkstoffen bei Tribologischer Beanspruchung' CY - Berlin, Germany DA - 2000-11-24 PY - 2001 N1 - Serientitel: BAM-Sonderheft – Series title: BAM-Sonderheft IS - 3 SP - 19 EP - 26 PB - BAM CY - Berlin AN - OPUS4-12656 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Hübner, Wolfgang A1 - Klein, P. A1 - Friedrich, K. T1 - Tribologische Eigenschaften ausgewählter PTFE-Werkstoffe bei tiefen Temperaturen T2 - 1. Symposoium IVW-BAM CY - Berlin, Germany DA - 2000-10-11 PY - 2000 AN - OPUS4-30893 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weihnacht, V. A1 - Makowski, S. A1 - Brückner, A. A1 - Theiler, Geraldine A1 - Gradt, Thomas T1 - Tribologie und Anwendung trocken laufender ta-C-Schichten KW - Tribologie KW - Verschleißschutzschichten KW - ta-C KW - DLC KW - Reibung KW - Verschleiß KW - Trockenreibung KW - Vakuumtribologie KW - Friction KW - Wear KW - Dry-running condition KW - Vacuum tribology PY - 2012 SN - 0724-3472 VL - 59 IS - 6 SP - 41 EP - 44 PB - Expert Verlag CY - Renningen AN - OPUS4-28004 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gradt, Thomas A1 - Theiler, Géraldine T1 - Tribological properties of polymer composites for applications in LNG environment N2 - In a first test series, the friction and wear properties of 6 polymeric candidate materials for application in LNG tribosystems were tested. The most favorable properties showed PTFE composite, filled with carbon fibers and PEEK, which showed low and stable friction and a wear coefficient in the order of 10-7 mm3N-1m-1. PTFE containing PEEK composites seem to be also appropriate for LNG applications. Admixtures of graphite as solid lubricant result in lower wear. Contrary, a lubricating mechanism of MoS2 was not observed. The PI-materials showed comparatively high friction and medium wear. T2 - 21th International Colloquium Tribology CY - Stuttgart/Ostfildern, Germany DA - 09.01.2018 KW - Tribology KW - PEEK KW - PTFE composites KW - Friction PY - 2018 SP - 1 EP - 2 AN - OPUS4-43900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Theiler, Geraldine A1 - Gradt, Thomas T1 - Tribological characteristics of polyimide composites in hydrogen environment N2 - The influence of hydrogen environment on the friction and wear behavior of polyimide (PI) composites was investigated for two different PI-types (PI1 and PI2) filled with natural or synthetic graphite. Sliding tests were run against AISI 52100 steel and the worn surfaces as well as the transfer film were analyzed by means of SEM, EDX and Infrared Spectroscopy. Results indicate that the chemical structure of the polyimide has a major influence on the tribological behavior. While the friction of PI2 remains rather stable in all environments, PI1 showed very low friction in hydrogen without any lubricant. The lubricity of graphite was found to be more effective in hydrogen than in moist air. KW - Sliding friction KW - Polyimide KW - Graphite KW - Hydrogen PY - 2015 DO - https://doi.org/10.1016/j.triboint.2015.06.001 SN - 0301-679X VL - 92 SP - 162 EP - 171 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-33555 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gradt, Thomas A1 - Theiler, Geraldine T1 - Tribological behaviour of solid lubricants in hydrogen environment T2 - World tribology congress 2009 CY - Kyoto, Japan DA - 2009-09-06 KW - Tribologie KW - Kompositwerkstoffe KW - Festschmierstoffe KW - Wasserstoff PY - 2009 SN - 978-4-9900139-9-8 IS - B1-122 SP - 15 AN - OPUS4-20137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gradt, Thomas A1 - Theiler, Geraldine T1 - Tribological behaviour of solid lubricants in hydrogen environment N2 - For further development of hydrogen technology, it is necessary to have a sufficient number of materials for safe and reliable operation available. Frictional contacts exposed to hydrogen, are critical because of vanishing protective oxide layers in the presence of a chemical reducing environment. Furthermore, liquid lubricants are often not applicable, because of purity requirements, or very low temperatures in the case of liquid hydrogen. Thus, for numerous tribosystems in hydrogen technology, solid lubrication is the only possible method for reducing friction and wear. Therefore, investigations on the tribological behaviour of friction reducing materials, such as PTFE, graphite, DLC and MoS2, in inert and hydrogen environment were carried out. The results show that solid lubricants, applied as coatings or as components in polymer composites, are able to reduce friction and wear in gaseous as well as in liquid hydrogen. However, some materials are very sensitive to the environmental medium. KW - Hydrogen environment KW - Low temperatures KW - Solid lubricants KW - Coatings KW - Polymer composites PY - 2011 DO - https://doi.org/10.247/trol.6.117 SN - 1881-2198 VL - 6 IS - 2 SP - 117 EP - 122 CY - Tokyo, Japan AN - OPUS4-23252 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hübner, Wolfgang A1 - Theiler, Geraldine A1 - Klein, P. A1 - Friedrich, K. T1 - Tribological behaviour of PTFE composites against steel at cryogenic temperatures T2 - 2nd World Tribology Congress ; 2nd WTC 2001 CY - Vienna, Austria DA - 2001-09-03 KW - PTFE composite KW - Cryogenic temperature KW - Transfer film KW - SEM KW - XPS PY - 2001 SN - 3-901657-09-6 SP - 1(?) EP - 4(?) PB - ÖTG CY - Vienna AN - OPUS4-12660 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Gradt, Thomas T1 - Tribological behaviour of PEEK composites in vacuum environment T2 - 12th European Space Mechanisms and Tribology Symposium (ESMATS 12) CY - Liverpool, England DA - 2007-09-19 PY - 2007 AN - OPUS4-17480 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Theiler, Geraldine A1 - Gradt, Thomas ED - Wilson, Andrew T1 - Tribological Behaviour of PEEK Composites in Vacuum Environment N2 - For tribological components working under extreme conditions, such as vacuum, or broad temperature ranges, it is often a problem to achieve acceptable durability of their friction parts. Thus, new material requirements are involved for these tribo-systems, in particular regarding operability and reliability. At BAM, several projects were conducted in the recent years, dealing with the tribological properties of friction couples at cryogenic temperature and in vacuum environment. This paper describes the vacuum and ultra high vacuum tribometers constructed at BAM and presents experiments carried out with polymer composites. The experiments presented were performed with PEEK, filled with solid lubricants, against 304 steel with a pin-on-disc configuration in oscillating sliding. Friction tests were carried out in vacuum in the temperature range between -40°C and +160°C and in ultra high vacuum at room temperature. KW - Tribologie KW - Vakuum KW - Polymere KW - Kompositwerkstoffe KW - Festschmierstoffe PY - 2007 SN - 92-9291-217-6 SN - 1609-042X SP - 1 EP - 5 AN - OPUS4-17399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Gradt, Thomas T1 - Tribological behaviour of graphite filled polyimide composites in hydrogen environment T2 - ECCM16 - 16th European conference on composite materials CY - Seville, Spain DA - 2014-06-22 KW - Polyimide composites KW - Graphite KW - Hydrogen environment KW - Vacuum PY - 2014 SN - 978-84-616-9798-4 SP - Paper 1137, 1 EP - 8 AN - OPUS4-31181 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Klein, P. A1 - Theiler, Geraldine A1 - Friedrich, K. T1 - Tribological behavior of short Carbon fiber reinforced PTFE- and PEEK-compounds T2 - 15th International Sealing Conference CY - Stuttgart, Germany DA - 2008-10-07 KW - Polymer composite KW - Tribology KW - Low temperatures PY - 2008 SN - 978-3-00-025884-8 IS - A 22 SP - 292 EP - 301 PB - Leithner Media Production CY - Ebelsbach AN - OPUS4-19518 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Hübner, Heinz A1 - Klein, P. A1 - Friedrich, K. T1 - Tribological beaviour of PTFE-composite against steel at cryogenic temperatures T2 - 2. World Tribology Congress 2001 CY - Vienna, Austria DA - 2001-09-03 PY - 2001 AN - OPUS4-30888 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Meine, Kerstin A1 - Hübner, Wolfgang A1 - Klein, P. A1 - Friedrich, K. ED - Bageur, G. G. ED - Seyfert, P. T1 - Thermal shock cycle experiments between room and cryogenic temperatures on polymer composites T2 - ICEC 19 - 19th International Cryogenic Engineering Conference CY - Grenoble, France DA - 2002-07-22 PY - 2002 SN - 81-7319508-0 SP - 729 EP - 732 PB - Narosa Publ. House CY - New Delhi AN - OPUS4-12662 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Brice, H. A1 - Gradt, Thomas T1 - Stick-slip behaviour of polymer films in LHe N2 - Superconducting magnets are susceptible to quenching, even with the smallest amounts of energy disturbances due to the extremely low thermal capacity of materials at 4.2 K. Hence, small mechanical disturbances resulting in frictional heating can be sufficient to exceed the wire’s critical temperature, causing it to quench. Unfortunately, relative motion between surfaces in the magnet System is inevitable due to various forces present in the System, including winding pretension, differences in material thermal contraction and the large electromagnetic forces. Typically insulating polymers are present at this interface to achieve the required electrical insulation requirements. T2 - WTC 2013 - 5th World tribology congress CY - Torino, Italy DA - 08.09.2013 PY - 2013 SP - Paper 366, 1 EP - 4 AN - OPUS4-30940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Brice, H. T1 - Stick-slip behavior of polymer films in LHe T2 - World Tribology Congress 2013 CY - Turin, Italy DA - 2013-09-08 PY - 2013 AN - OPUS4-29664 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Géraldine A1 - Gradt, Thomas T1 - Sliding performance of polymer materials in hydrogen and methane N2 - In this talk, the sliding performance of polymer materials in hydrogen and methane are presented. The influence of the environmental conditions is discussed in terms of material composition, counterface, transfer film formation, and triboreactions. T2 - International Tribology Conference/ITC CY - Sendai, Japan DA - 17.09.2019 KW - Friction KW - Wear KW - Polymer composites KW - Hydrogen KW - Methane PY - 2019 AN - OPUS4-49148 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhang, Z. A1 - Klein, P. A1 - Theiler, Geraldine A1 - Hübner, Wolfgang T1 - Sliding performance of polymer composites in liquid hydrogen and liquid nitrogen N2 - Outstanding features favour the application of polymers and polymer composites in low-temperature technology. The booming hydrogen technology is a challenge for these materials, which are considered as seals and bearings in cryogenic pumps. In the present study, three types of thermoplastics, i.e., polyetheretherketone (PEEK), polyetherimide (PEI) and polyamide 6,6 (PA6,6), and one epoxy were considered as matrix materials. Micron-sized fillers, i.e., short carbon fibres, graphite flakes, and PTFE powders, were incorporated into these polymers together with nano-sized TiO2 particles. Optimised compositions of each matrix were selected from our previous works at room temperature in order to be studied at very low temperature conditions. In particular, frictional tests were carried out with polymer composite pins against polished steel surfaces under constant load over a certain distance in liquid hydrogen and liquid nitrogen. Afterwards, worn surfaces were analysed by using scanning electron microscopy (SEM). It was found out that the tribological properties in liquid hydrogen are dominated by the matrix materials, in particular thermoplastics perform generally slightly better than thermosetting resins. PY - 2004 SN - 0957-4530 SN - 1573-4838 VL - 39 IS - 9 SP - 2989 EP - 2995 PB - Springer CY - Norwell, Mass. AN - OPUS4-12664 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Géraldine T1 - Sliding behaviour of polymer materials in hydrogen N2 - This lecture deals with the sliding behaviour of polymer materials in hydrogen environment. After a short introduction of the hydrogen activities at BAM, the tribological performances of polymer materials in gaseous hydrogen are presented and compared with air and vacuum environment. The second part focusses on the influence of the counterface materials in hydrogen. Finally, the last section is dedicated to experiments liquid hydrogen. T2 - Invited lecture, TRIBOS+ program at Lulea University of Technology CY - Lulea, Sweden DA - 30.06.2021 KW - Polymers KW - Hydrogen KW - Friction KW - Wear PY - 2021 AN - OPUS4-53708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine T1 - Sliding behaviour of polymer composites in hydrogen environment T2 - International Tribology Conference/ITC 2015 CY - Tokyo, Japan DA - 2015-09-15 PY - 2015 AN - OPUS4-34323 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Hübner, Wolfgang A1 - Gradt, Thomas A1 - Klein, P. A1 - Friedrich, K. T1 - Reibung und Verschleiß von kohlefaser-gefüllten Polymeren bei Raum und Tieftemperaturen T2 - DGM Tagung CY - Fürth, Germany DA - 2004-03-10 PY - 2004 AN - OPUS4-30884 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gradt, Thomas A1 - Theiler, Geraldine A1 - Hale, H. T1 - Reibeigenschaften von Polymerfolien in Flüssighelium N2 - Starke Magnetfelder, wie sie z.B. für die Magnetresonanztomografie (MRT) notwendig sind, werden durch supraleitende Spulen erzeugt, die mit Flüssighelium auf eine Temperatur von -269°C gekühlt werden. Die Reibungswärme, die z.B. bei kleinsten Bewegungen zwischen der Spule und deren Stützstruktur entsteht, kann bewirken, dass die kritische Temperatur des Supraleiters lokal überschritten wird und ein normalleitender Bereich entsteht. Aufgrund der bei Normalleitung entstehenden jouleschen Wärme kann sich dieser Bereich weiter erwärmen und schnell ausbreiten. Dieser Vorgang wird als Quench bezeichnet und führt zum schlagartigen Verdampfen des extrem teuren Kältemittels und zu Betriebsunterbrechungen von mehreren Tagen. Da diese Quenche durch Reibungswärme verursacht werden, ist es notwendig, das Reibverhalten der beteiligten Werkstoffe so zu optimieren, dass kein kritischer Betriebszustand erreicht wird. Dies betrifft in erster Linie Polymerfolien, die zur elektrischen Isolierung zwischen der Spule und der Stützstruktur notwendig sind. Neben zu hoher Reibung allgemein müssen ausgeprägte Haftreibungsspitzen und StickSlip-Effekte vermieden werden. Mit diesem Ziel wurde das Reibverhalten von PTFE-, PET- und Pl-Folien bei tiefen Temperaturen und den für diese Anwendung typischen niedrigen Gleitgeschwindigkeiten untersucht. Es zeigte sich, dass die Reibung zwischen Polymeroberflächen in Flüssighelium allgemein höher, aber stabiler als in Flüssigstickstoff ist. Allerdings hängt das Reibverhalten erheblich von der Werkstoffpaarung ab. Der Stick-Slip-Effekt nimmt bei allen untersuchten Polymer-Polymer-Paarungen mit wachsender Kontaktpressung zu. PET gegen PET hat das ungünstigste Reibverhalten und sollte bei hohen Pressungen vermieden werden. Zum Vergleich getestete Paarungen von Polymeren gegen Aluminium zeigten deutlich günstigeres Reibverhalten ohne signifikanten Stick-Slip. Deshalb sollte bei derartigen Anwendungen sichergestellt werden, dass die Gleitebene zwischen Polymer- und Metalloberfläche liegt. T2 - 55. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß - Forschung und praktische Anwendungen CY - Göttingen, Germany DA - 22.09.2014 PY - 2014 SN - 978-3-00-046545-1 VL - II SP - 41/1 EP - 41/10 AN - OPUS4-31529 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Theiler, Géraldine T1 - PTFE- and PEEK-Matrix Composites for Tribological Applications at Cryogenic Temperatures and in Hydrogen N2 - Many new technologies are based on applications in extreme conditions, such as at low temperatures or in hydrogen environment. This involves new requirements on material properties, in particular regarding their operability and reliability. To fulfil this demand, the tribological behaviour of PTFE- and PEEK-matrix composites filled with carbon fibres were investigated at cryogenic temperatures and in hydrogen by means of surface analyses. For a better understanding of the tribological behaviour, and because of the temperature-dependent characteristics of polymer materials, thermal and mechanical properties of selected composites were initially investigated at low temperatures. Thermal shock experiments as well as cryo- and hydrogen treatments were carried out. Different coefficients of thermal expansion within the composite lead to debondings of particles, particularly in the case of PTFE materials. Tensile tests indicate that the YOUNG'S modulus increases at T= 77 K compared to room temperature. However, this improvement at low temperatures is moderate for PEEK composite which is already under its glass transition at room temperature. In the main investigation, tribological experiments were carried out at first at T= 77 K to observe the influence of the matrix, fillers and fibres on the material behaviour comparing to room temperature. The reduction of the friction coefficient and wear at low temperatures has been attributed to the low temperature properties of the polymer in particular due to the higher YOUNG'S modulus at T= 77 K. Whereas at room temperature friction and wear depend strongly of the CF content, the quantity of fillers and fibres does not have a significant effect on the tribological behaviour at low temperatures. At T= 77 K, the tribological behaviour of PTFE and PEEK composites is mainly influenced by the matrix. PEEK composites have a better tribological performance than PTFE materials especially regarding the wear resistance. Furthermore, the influence of the cryogenic medium was determined with experiments carried out in LN2 (T= 77 K), LH2 (T= 20 K) and LHe (T= 4.2 K), as well as in helium at T= 77 K and hydrogen at room temperature. The thermal properties of the cryogenic medium have a significant influence on the tribological performances of the composites. Due to the lower frictional heat at low sliding speed, the effect of low temperatures on the tribological behaviour of these composites was more clearly detected in this case, with a change in wear mechanism from mainly adhesive to more abrasive. Experiments in LN2 give the best friction and wear performance at low as well as at high sliding speed. The behaviour of these composites in LHe does not benefit from the low temperature properties of polymers due to the low heat of evaporation of LHe. The influence of hydrogen was particularly seen after the tribological experiments performed in LH2 on the surface of the disc. The reduction effect of hydrogen may have an influence on the tribochemical reactions which appear during sliding, enhancing the formation of iron fluorides, but no influence of the metal fluorides on the tribological performance could be determined in this study. N2 - Viele neue Technologien nutzen Anwendungen bei extremen Bedingungen, wie etwa bei tiefen Temperaturen oder in Wasserstoffumgebung. Dies stellt neue Forderungen an die Werkstoffe, insbesondere an ihre Funktionsfähigkeit und Zuverlässigkeit. Um dem gerecht zu werden, wurde das tribologische Verhalten von kohlefaserverstärkten PTFE- und PEEKVerbundwerkstoffen bei tiefen Temperaturen und in Wasserstoff mit Hilfe von Oberflächenanalysen untersucht. Für ein besseres Verständnis des tribologischen Verhaltens und wegen der temperaturabhängigen Eigenschaften der Polymere wurden zuerst thermische und mechanische Untersuchungen bei tiefen Temperaturen durchgeführt. Temperatur-Wechselbeanspruchungen sowie Kryo- und Wasserstoffbehandlungen wurden durchgeführt. Unterschiedliche Wärmeausdehnungskoeffizienten innerhalb der Materialien verursachen Trennungen von Partikeln besonders bei PTFE-Verbundwerkstoffen. Experimente zur Bestimmung der Zugfestigkeit zeigen an, dass der E-Modul bei T = 77 K im Vergleich zur Raumtemperatur zunimmt. Diese Verbesserung ist jedoch für PEEKMaterial nicht sehr ausgeprägt, da es sich bei Raumtemperatur bereits unter seinem Glasübergang befindet. In der Hauptuntersuchung wurden tribologische Experimente zuerst bei T = 77 K durchgeführt, um den Einfluss der Matrix, der Füllstoffe und der Fasern auf das Materialverhalten im Vergleich zur Raumtemperatur zu beobachten. Der Reibwert- und die Verschleißabnahme bei T = 77 K ist mit den Tieftemperatur-Eigenschaften der Polymer-Materialien zu erklären, insbesondere wegen des höheren E-Moduls bei T = 77 K. Während Reibung und Verschleiß bei Raumtemperatur stark von dem CF-Gehalt abhängig sind, hat die Menge der Füllstoffe und der Fasern wenigen Effekt auf das tribologische Verhalten bei tiefen Temperaturen. Bei 77 K ist das tribologische Verhalten von PTFE und PEEK hauptsächlich durch die Matrix bestimmt. PEEK-Komposite haben ein besseres tribologisches Verhalten als PTFE, insbesondere im Hinblick auf den Verschleißwiderstand. Außerdem wurde der Einfluss des Kältemittels mit tribologischen Experimenten untersucht, die in LN2 (T = 77 K), LH2 (T = 20 K) und LHe (T = 4,2 K), sowie in Helium bei T = 77 K und Wasserstoff bei Raumtemperatur durchgeführt wurden. Die thermischen Eigenschaften des Kältemittels haben einen bedeutenden Einfluss auf die tribologischen Eigenschaften. Wegen der niedrigeren Reibungswärme bei geringerer Gleitgeschwindigkeit wurde die Wirkung der Tieftemperaturen auf das tribologische Verhalten dieser Verbundwerkstoffe in diesem Fall besonders deutlich. Dabei ist der Wechsel des Verschleißmechanismus von vorwiegend adhäsiv zu vorwiegend abrasiv zu beobachten. Ergebnisse in LN2 zeigen die niedrigsten Reibungszahlen und Verschleißwerte, sowohl bei niedriger als auch bei hoher Gleitgeschwindigkeit. Das Verhalten dieser Verbundwerkstoffe in LHe profitiert aufgrund dessen geringer Verdampfungswärme nicht von den Tieftemperatur-Eigenschaften der Polymere. Der Einfluss des Wasserstoffs wurde besonders bei den Oberflächenanalysen der Scheibe nach den tribologischen Experimenten in LH2 beobachtet. Die reduzierende Eigenschaft des Wasserstoffs könnte einen Einfluss auf die tribochemischen Reaktionen und darüber hinaus eine fördernde Wirkung auf die Bildung der Metallfluoride haben. Ein Einfluss dieser Metallfluoride auf das tribologische Verhalten konnte in dieser Arbeit nicht beobachtet werden. T3 - BAM Dissertationsreihe - 14 KW - Oberflächenanalyse KW - Tiefe Temperaturen KW - Tribologie PY - 2005 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-1444 SN - 978-3-86509-378-7 SN - 1613-4249 VL - 14 SP - 1 EP - 132 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gradt, Thomas A1 - Theiler, Géraldine T1 - Polymerwerkstoffe für Tribosysteme in tiefkalt verflüssigtem Erdgas N2 - Der Beitrag handelt von der Eignung von Polymeren für Anwendungen in LNG. Um dies zu testen, wurde das tribologische Verhalten von PEEK-, PTFE-, PI-, und UHMW-PE-basierten Werkstoffen im Gleitkontakt gegen CrNi-Stahl untersucht. T2 - 59. Tribologie-Fachtagung CY - Göttingen, Germany DA - 24.09.2018 KW - Alternative Kraftstoffe KW - CNG KW - LNG KW - Trockenreibung KW - Polymerkomposite PY - 2018 SN - 978-3-9817451-3-9 SP - 59/1 EP - 59/4 AN - OPUS4-46177 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Gradt, Thomas T1 - Polymer composites for tribological applications in hydrogen environment T2 - International Conference of Hydrogen Safety CY - San Sebastián, Spain DA - 2007-09-11 PY - 2007 AN - OPUS4-17477 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Gradt, Thomas ED - Inaki Azkarate, ED - Estibaliz Ezponda, ED - Marco Nicola Carcassi, ED - Marangon, Alessia ED - Elena Rossi, T1 - Polymer composites for tribological applications in hydrogen environment N2 - In the development of hydrogen technology, special attention is paid to the technical problems of hydrogen storage. One possible way is cryogenic storage in liquid form. Generally cryotechnical machines need components with interacting surfaces in relative motion such as bearings, seals or valves, which are subjected to extreme conditions. Materials of such systems have to be resistant to friction-caused mechanical deformation at the surface, low temperatures and hydrogen environment. Since materials failure can cause uncontrolled escape of hydrogen, new material requirements are involved for these tribo-systems, in particular regarding operability and reliability. In the past few years several projects dealing with the influence of hydrogen on the tribological properties of friction couples were conducted at the Federal Institute for Materials Research and Testing, (BAM), Berlin. This paper reports some investigations carried out with polymer composites. Friction and wear were measured for continuous sliding and analyses of the worn surfaces were performed after the experiments. Tests were performed at room temperature in hydrogen as well as in liquid hydrogen. T2 - 2nd International Conference on Hydrogen Safety CY - San Sebastián, Spain DA - 2007-09-11 KW - Hydrogen KW - Polymer composite KW - Tribology PY - 2007 SN - 978-84-95520-15-9 SP - 1 EP - 9 CY - San Sebastián, Spain AN - OPUS4-18429 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Friedrich, K. A1 - Theiler, Geraldine A1 - Klein, P. ED - Sujeet K. Sinha, ED - Brian J. Briscoe, T1 - Polymer composites for tribological applications in a range between liquid Helium and room temperature KW - Polymer composites KW - Tribology PY - 2009 SN - 978-1-84816-202-0 IS - Chapter 11 SP - 375 EP - 415 PB - Imperial College Press AN - OPUS4-19517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Gradt, Thomas A1 - Banova, Z. A1 - Schlarb, A.K. T1 - PEEK-Komposite für Reibsysteme in der Vakuumtechnik T2 - Fachtagung der Gesellschaft für Tribologie 2007 CY - Göttingen, Germany DA - 2007-09-24 PY - 2007 AN - OPUS4-17482 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Theiler, Geraldine A1 - Gradt, Thomas A1 - Banova, Z. A1 - Schlarb, A.K. T1 - PEEK-Komposite für Reibsysteme in der Vakuumtechnik N2 - Aim of the investigation is to characterize selected PEEK-composites in vacuum environment. Oscillating sliding friction was investigated with a pin-on-disc configuration in high vacuum (10-5 mbar) at room temperature, -40 °C, +100 °C and +160 °C. The contact pressure was 1 MPa and 7 MPa respectively , the maximum sliding velocity 0.1 m/s. Furthermore, tests in ultra high vacuum (10-9 mbar) were carried out with flat and spherical pins at 1 MPa and 60 MPa respectively. Among the tested materials MoS2 filled PEEK shows the best tribological performance in vacuum. Particularly, in the lower temperature range and at higher loads the friction behaviour is improved by MoS2 content. KW - Vakuum KW - Polymer composite KW - Tribology KW - PEEK Komposite KW - Hochvakuum KW - Temperatureinfluss KW - MoS2 KW - Grafit KW - PEEK composites KW - High vacuum KW - Influence of the temperature KW - Graphite PY - 2008 SN - 0724-3472 VL - 55 IS - 5 SP - 25 EP - 30 PB - Expert Verlag CY - Renningen AN - OPUS4-18306 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Gradt, Thomas A1 - Banova, Z. A1 - Schlarb, A.K. T1 - PEEK-Komposite für Reibsysteme in der Vakuumtechnik KW - Vakuum KW - Polymer composite KW - Tribology PY - 2007 SN - 978-3-00-022603-8 VL - I SP - 19/1 EP - 19/12 CY - Aachen AN - OPUS4-17364 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, K. A1 - Klein, P. A1 - Theiler, Geraldine A1 - Ye, L. A1 - Mai, Y.W. T1 - PEEK- and PTFE- Based Composites for Tribology Applications in a Range between Liquid Helium and Room Temperature N2 - This study deals with the development of PEEK (polyehteretherketone) and PTFE (polytetrafluoroethylene) based composites, optimized for low friction and low wear performance under extreme environments. It is demonstrated that the incorporation of a harder polymer component into PTFE (such as PEEK particles), a short fiber reinforcement (e.g. carbon fibers CF), and internal lubricants (e.g. PTFE particles), helps to reduce the friction and to improve the wear resistance over a very wide temperature range. KW - Composites KW - Tribology KW - PEEK KW - PTFE KW - Temperature KW - Friction KW - Wear PY - 2007 SN - 1013-9826 VL - 334-335 SP - 597 EP - 600 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-15045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Géraldine T1 - On the tribological behaviour of polymer composites in vacuum N2 - This lecture deals with the sliding behaviour of polymer composites in vacuum environment. At first, the effect of the polymer matrix and solid lubricants such as graphite and MoS2 are presented. The second part focusses on the influence of the residual pressure with experimental results obtained in high and ultrahigh vacuum. T2 - Invited lecture, TRIBOS+ program at Lulea University of Technology CY - Lulea, Sweden DA - 29.06.2021 KW - Polymers KW - Vacuum KW - Friction KW - Wear PY - 2021 AN - OPUS4-53710 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Theiler, Géraldine A1 - Harsha, A. P. A1 - Gradt, Thomas T1 - On the sliding wear behavior of PEAK composites in vacuum environment N2 - The tribological behavior of neat and filled PEEK and PEKK composites were compared in air and vacuum conditions. Very low friction and wear coefficient were obtained at low sliding speed while severe wear occurred at high speed. Experimental results are discussed by analysing the transfer film and wear debris. KW - PEAK KW - Composites KW - Wear KW - Friction KW - Vacuum PY - 2019 DO - https://doi.org/10.1115/1.4042271 SN - 0022-2305 SN - 0742-4787 VL - 141 IS - 4 SP - 044502-1 EP - 044502-7 PB - ASME AN - OPUS4-47298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Géraldine A1 - Harsha, A. P. A1 - Gradt, Thomas T1 - On the sliding behavior of PAEK composites in vacuum environment N2 - The tribological behavior of PAEK composites were investigated in air and vacuum environment. Results indicate that the tribological performance of these compounds depends on material compositions, fiber orientation as well as test conditions. In vacuum, very low friction and wear coefficient were obtained at low sliding speed while severe wear occurred at high speed. T2 - The 6th World Tribology Congress - WTC 2017 CY - Beijing, China DA - 17.09.2017 KW - PAEK KW - Sliding performances KW - Vacuum PY - 2017 AN - OPUS4-42447 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -