TY - JOUR A1 - Meine, Kerstin A1 - Kloß, K. A1 - Schneider, Thomas A1 - Spaltmann, Dirk T1 - The influence of surface roughness on the adhesion force N2 - Adhesion measurements are presented which were carried out with an atomic force microscope between polymer balls attached to a cantilever and a silicon wafer under ultra high vacuum conditions. In using a silicon surface with a defined structure a correlation between adhesion force and contact area was found. This correlation could partly be explained by the Johnson-Kendall-Roberts model, if a change of the surface energy is assumed as a result of the structuring. For a constant geometric contact area an additional structuring leads to a decrease of the adhesion force. T2 - 10th European Conference on Applications of Surface and Interface Analysis (ECASIA '03) CY - Berlin DA - 2003-10-05 KW - Roughness KW - Adhesion KW - AFM KW - UHV KW - JKR model KW - Surface energy PY - 2004 DO - https://doi.org/10.1002/sia.1738 SN - 0142-2421 SN - 1096-9918 VL - 36 IS - 8 SP - 694 EP - 697 PB - Wiley CY - Chichester AN - OPUS4-4708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Spaltmann, Dirk A1 - Schneider, Thomas A1 - Witke, Klaus A1 - Brzezinka, Klaus-Werner A1 - Löhr, Manuel A1 - Binkowski, Sigrid A1 - Woydt, Mathias T1 - Raman-Untersuchungen an tribologisch belasteten diamantartigen Kohlenstoffschichten T2 - Dünnschichtseminar der Universität Duisburg-Essen CY - Essen, Germany DA - 2005-07-07 PY - 2005 AN - OPUS4-10964 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spaltmann, Dirk A1 - Hartelt, Manfred A1 - Woydt, Mathias T1 - Ultra-high frequency tribometer for reciprocating sliding motion N2 - A novel tribometer has been designed using commercially available components for sliding motion at 40kHz with amplitude between 2.5 and 5µm. The tribometer is equipped with means to measure amplitude, frequency, power required to keep the sample in motion and load applied. The effective motion between the two contacting bodies is monitored. These data are used to evaluate the coefficient of friction. The wear rate was determined after the tests. The set-up was tested using novel, non-commercial substrates such as AlFeCrTi-alloys and tungsten carbide-based coatings as well as Magnéli-type coatings (Tin-2Cr2O2n-1 and TinO2n-1). This paper presents the principle of the ultra-high frequency tribometer and first tribological quantities of materials and coatings tested. KW - Frequency KW - Tribometer KW - Sliding KW - Friction KW - Wear KW - Aluminium alloy KW - Oscillation KW - Magnéli-type phases PY - 2007 DO - https://doi.org/10.1002/tt.41 SN - 1354-4063 SN - 1557-685X VL - 13 IS - 4 SP - 153 EP - 164 PB - Coppin CY - Deal AN - OPUS4-16047 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Manier, Charles-Alix A1 - Spaltmann, Dirk A1 - Woydt, Mathias ED - Christophe Donnet, ED - Erdemir, Ali T1 - Tribology of DLC Films Under Slip-Rolling Conditions KW - DLC coating KW - Diamond KW - Steel KW - Wear KW - Friction KW - Slip rolling KW - Lubrication PY - 2008 SN - 978-0-387-49891-1 SP - 383 EP - 409 PB - Springer Science + Business Media CY - New York AN - OPUS4-16495 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Manier, Charles-Alix A1 - Spaltmann, Dirk A1 - Woydt, Mathias A1 - Lippitz, Andreas A1 - Unger, Wolfgang T1 - NEXAFS study of carbon hard coatings tribo-tested under slip-rolling conditions KW - Synchrotron KW - NEXAFS KW - Carbon hard coating KW - Tribology PY - 2007 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annual_report_2006.pdf#page=159 SN - 0179-4159 SP - 159 EP - 161 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-17452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klaffke, Dieter A1 - Santner, Erich A1 - Spaltmann, Dirk A1 - Woydt, Mathias T1 - Influences on the tribological behaviour of slip-rolling DLC-coatings N2 - Diamond like carbon (DLC)-coatings are applied very successfully on computer discs. Sliding friction tests confirm their high performance as dry lubricants with friction coefficients (COFs) below 0.1. In contrast to sliding tests, until very recently most of the DLC-coatings failed in slip-rolling test after fewer cycles than uncoated samples. However, present tests with DLC-coatings of seven different suppliers show a more promising tribological behaviour under slip-rolling conditions. The DLC-coatings were deposited onto steel 100Cr6, HRC 60, with a thickness of 2–3 ?m. The counter bodies were uncoated, grinded or polished 100Cr6 discs with 30 mm radius of curvature. The tests were performed on a twin disc testing rig (Amsler type) with paraffin oil under boundary/mixed lubrication and rolling with 10% slip. The initial, average Hertzian contact pressure was adjusted to Pm = 1.0, 1.25, and 1.5 GPa. The failure criterion was defined as the occurrence of a single damaged area larger than 1 mm2, which was controlled by optical microscopy (OM). An acoustic emission (AE) measurement system was installed as an additional online control for coating failure. The stressed coatings and the chipping areas were analyzed by OM, SEM, EDX, AFM and Raman spectroscopy. Until now, the results reveal that a large scatter in lifetime of coatings occurs not only between samples of different coaters but also between the samples of one single batch. The highest lifetime reached by a DLC-coating under these testing conditions is 10 × 106 cycles. That is the highest life time for a coating tested under the testing conditions above in our laboratory so far. The following factors were identified to influence the life time of the coatings: coating thickness, interlayer type, topography of the coatings, counter body roughness and mechanical properties. But the most important factor determining the life time of the coatings is that the coating process does produce homogenous layers free of faults. KW - DLC-coatings KW - Slip-rolling KW - Life time KW - Acoustic emission PY - 2005 DO - https://doi.org/10.1016/j.wear.2005.01.008 SN - 0043-1648 VL - 259 SP - 752 EP - 758 PB - Elsevier CY - Amsterdam AN - OPUS4-7557 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - Woydt, Mathias A1 - von Gablenz, A. T1 - JATROPHA - The seed of energy CO2-neutral fuels and lubricants based on sustainable non-food oils T2 - TAE Esslingen: 7th International Colloquium Fuels CY - Ostfildern, Germany DA - 2009-01-14 PY - 2009 AN - OPUS4-18470 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manier, Charles-Alix A1 - Spaltmann, Dirk A1 - Theiler, Geraldine A1 - Woydt, Mathias T1 - Carboneous coatings by rolling with 10% slip under mixed/boundary lubrication and high initial Hertzian contact pressures N2 - Costs reduction is one of the major objectives in mechanical applications with a parallel increase of the power output. Another driver represents new environmental standards and their increasing restrictions in the automotive industry leading to the question, if materials based concepts may substitute harmful EP/AW additives in lubricants. This paper presents the slip-rolling resistance of different DLC/THC coatings on steel substrates with a definite slip rate of 10%. Industrial DLC coatings of ta-C and a-C:H types from various manufacturers were deposited on steels SAE 52100 and AMS 5898 to compile the slip-rolling resistance under initial average Hertzian contact pressures between 1.5 GPa and 2 GPa. The tests were carried out on Amsler-type twin disc tribometer under the regime of mixed/boundary lubrication in unadditivated paraffinic oil (ISO VG 46) and a factory fill engine oil. The spherical steel sample was uncoated and the cylindrical coated with DLC. Some coatings achieved 10 million cycles without any damage under a maximal Hertzian contact pressure Pmax well over 2.25 GPa, thus exceeding FZG 12. KW - DLC KW - Rolling KW - Mixed/boundary lubrication KW - Hertzian pressure PY - 2008 DO - https://doi.org/10.1016/j.diamond.2008.01.066 SN - 0925-9635 VL - 17 IS - 7-10 SP - 1751 EP - 1754 PB - Elsevier CY - New York, NY AN - OPUS4-17816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spaltmann, Dirk A1 - Hartelt, Manfred A1 - Woydt, Mathias T1 - Triboactive materials for dry reciprocating sliding motion at ultra-high frequency N2 - High-power piezo-electric motors with power densities of 1.4 kW/kg display a potential for substituting hydraulic actuators. For this application, two novel tribometers of the same type have been designed using commercially available components for sliding motion at 40 kHz with amplitudes between 2.5 µm and 5 µm. The tribometers are equipped with means to measure amplitude, frequency, power required to keep the samples in motion and load applied. The effective motion between the two contacting bodies is monitored in each of the tribometers. These data are used to evaluate the coefficient of friction. The wear rate was determined after the tests. The set-ups were tested using well-known 100Cr6H (AISI 52100) samples before investigating novel, non-commercial substrates such as AlFeCrTi-alloys and tungsten carbide-based coatings as well as Magnéli-type coatings (Tin-2Cr2O2n-1 and TinO2n-1). This paper presents the principle of the ultra-high frequency tribometers and first tribological quantities of materials and coatings tested up to and above 1011 cycles. Very low wear rates in the range 10-8 mm³/Nm down to 10-10 mm³/Nm were determined under dry oscillation in air. KW - Frequency KW - Tribometer KW - Sliding friction KW - Wear KW - Triboactive materials KW - Magnéli-type phases KW - Aluminium alloy KW - Oscillation PY - 2009 DO - https://doi.org/10.1016/j.wear.2008.06.004 SN - 0043-1648 VL - 266 IS - 1-2 SP - 167 EP - 174 PB - Elsevier CY - Amsterdam AN - OPUS4-18243 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -