TY - CONF A1 - Pfeffer, D. A1 - Scholz, Christian A1 - Belly, C. A1 - Wäsche, Rolf A1 - Schlaak, H.F. A1 - Pott, P.P. T1 - Influence of the actuation waveform on the performance of piezoelectric stick-slip actuators N2 - Performance and efficiency of piezo-electric stick-slip actuators are dependent on the waveform of the electrical actuation of the piezo-stack. This paper compares between a conventional saw-tooth actuation with two waveforms that feature softer acceleration in order to minimize the duration of the slip-phase. It is shown that the proposed waveforms increase both maximum mechanical output power (by 43%) and overall efficiency (by 25%) of the examined actuator. T2 - IKMT 2015 - Innovative Klein- und Mikroantriebstechnik CY - Köln, Germany DA - 14.09.2015 PY - 2015 SN - 978-3-8007-4072-7 N1 - Serientitel: ETG-Fachbericht – Series title: ETG-Fachbericht VL - 146 SP - 100 EP - 104 AN - OPUS4-34883 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scholz, Christian A1 - Wäsche, Rolf ED - Bartz, Wilfried J. T1 - Effect of sliding speed and relative humidity on the tribological behaviour of ceramic and polymer materials N2 - In many technical applications not only the actual friction coefficient is of importance, but rather the constancy is relevant for the functionality. Due to inconstant friction values, positioning processes can be substantially influenced. Aim of the present work is to characterize the effect of sliding speed and relative humidity on the tribological behavior of selected combinations. The tribological tests were carried out at room temperature in a ball-on-disk configuration at a normal load of 1 N and respectively 10 N under dry sliding conditions. The friction and wear behavior is significantly depending on the sliding speed and humidity conditions. Using a chamber enclosing the tribometer the relative humidity inside could be adjusted to dry (< 5% rH), normal (50% rH) and moist (100% rH) conditions during the testing time. Three different frequencies, 0.2 Hz, 2 Hz and 5 Hz, were used for tribological evaluations. Measuring the friction force hysteresis loop distinct differences in the frictional behavior of different material combinations could be observed. Materials selected were ceramics sliding against PP-based polymer and various polymers sliding against Ti6AlV4. T2 - 19th International colloquium Tribology - Industrial and automotive lubrication CY - Stuttgart/Ostfildern, Germany DA - 21.01.2014 KW - Stick slip KW - Polymer KW - Ceramic KW - Sliding speed KW - Relative humidity PY - 2014 SN - 978-3-943563-10-8 SP - Paper 8.11, 1 EP - 6 CY - Stuttgart/Ostfildern AN - OPUS4-30176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfeffer, D. A1 - Scholz, Christian A1 - Belly, C. A1 - Wäsche, Rolf A1 - Schlaak, H.F. A1 - Pott, P.P. T1 - Modular test bed for performance assessment of piezoelectric stick-slip actuators N2 - Stepping piezoelectric actuators based on the stick-slip effect inherently make use of a friction contact between strator and rotor. This contact defines not only the actuator's performance but also is prone to wear and tear. For broad use, the actuator has to be able to perform around 1 million strokes. To assess the actuator's performance in terms of force, speed, mechanical output, electrical input, and long-term stability under different load- and environmental conditions, as well as different friction partners, a dedicated test-bed for a LSPA30µXS motor by Cedrat Technologies has been set up. T2 - Actuator 2014 - 14th International conference on new actuators & 8th International exhibition on smart actuators and drive systems CY - Bremen, Germany DA - 23.06.2014 KW - Piezoelectric actuator KW - Test bed KW - Stick-slip KW - Performance test KW - Micro positioning PY - 2014 SN - 978-3-933339-22-5 SN - 978-3-933339-23-2 SP - P 50, 617 EP - 620 AN - OPUS4-33498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bui, M. A1 - Hoffmann, K. F. A1 - Braun, T. A1 - Riedel, S. A1 - Heinekamp, Christian A1 - Scheurell, K. A1 - Scholz, G. A1 - Stawski, Tomasz A1 - Emmerling, Franziska T1 - An Amorphous Teflate Doped Aluminium Chlorofluoride: A Solid Lewis-Superacid for the Dehydrofluorination of Fluoroalkanes N2 - Ananion-dopedaluminiumchlorofluoride AlCl0.1F2.8(OTeF5)0.1(ACF-teflate) was synthesized.The material contains pentafluor-oorthotellurate(teflate)groups, which mimic fluoride ions electronically, but are sterically more demanding. They are embedded into the amorphous structure. The latter was studied by PDF analysis, EXAFS data and MAS NMR spectroscopy. The mesoporous powder is a Lewis superacid, and ATR-IR spectra of adsorbed CD3CN reveal a blue-shift of the adsorption band by73 cm-1, which is larger than the shift for SbF5. Remarkably,ACF-teflate catalyzes dehydrofluorination reactions of mono-fluoroalkanes to yield olefins in C6D6. In these cases,no Friedel-Crafts products were formed. KW - Aluminium fluorides KW - Aluminium teflates KW - C-F bond activation KW - Lewis superacids KW - Silanes PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572290 DO - https://doi.org/10.1002/cctc.202300350 SN - 1867-3880 SP - 1 EP - 7 PB - Wiley VHC-Verlag AN - OPUS4-57229 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scholz, Philipp A1 - Vogel, Christian A1 - Schuck, G. A1 - Simon, Franz-Georg T1 - Speciation of copper and zinc compounds relevant for the hazard property (HP) 14 classification of municipal solid waste incineration bottom and fly ashes N2 - The analysis of the presence and content of substances that are toxic to aquatic life in waste is essential for classification of waste with regard to hazard property (HP) 14 ‘ecotoxic’. For the determination of HP14 classified copper (Cu) and zinc (Zn) compounds in various municipal solid waste incineration bottom ashes (IBA) and one fly ash (FA) from Germany we applied X-ray absorption near-edge structure (XANES) spectroscopy in combination with linear combination fitting. The analysis showed that approx. 50–70% of Cu in the IBA are Cu(I) compounds and elemental Cu(0), but these compounds were not equally distributed in the different IBA. In contrast, the majority (approx. 50–70%) of Zn in all IBA is elemental zinc, which originates from brass or other alloys and galvanized metals with a large content of zinc in the waste. The FA contain higher mass fraction on Zn and other toxic elements, but similar Cu and Zn species. Additional performed selective extraction at a pH of 4 with an organic acid of some IBA showed that the ecotoxic Zn fraction is mainly elemental zinc and zinc oxide. In contrast, for the ecotoxic Cu fraction within the IBA no specific compound could be identified. Furthermore, the XANES analysis showed that the HP14 properties of especially Cu in IBA is overestimated with current best-practice guidelines for sample processing for the current substance-related approach with the 0.1% cut-off rule for each substance. However, it should be considered whether it would not be better from an environmental point of view to take the ecotoxicologically leachable copper and zinc as a reference value. KW - Thermal waste treatment KW - XANES spectroscopy KW - Ecotoxicity KW - Incineration bottom ash PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-609584 DO - https://doi.org/10.1016/j.wasman.2024.09.001 VL - 189 SP - 421 EP - 426 PB - Elsevier Ltd. AN - OPUS4-60958 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Vogel, Christian A1 - Simon, Franz-Georg A1 - Scholz, Philipp T1 - The chemical state of antimony and vanadium species in municipal solid waste incineration bottom ash N2 - Due to the large quantity as residual mineral waste, municipal solid waste incineration - bottom ash (MSWI-BA) is an interesting secondary raw material that can be utilized for road construction. However, leaching of chloride, sulfate and potentially hazardous heavy metals from MSWSI-BA into the environment may cause problems in utilization of it in civil engineering. In a previous study, we performed a long-term leaching test of MSWI-BA in a lysimeter for almost six years to investigate the efficiency of the treatment process on the release of hazardous substances. While concentrations of chloride, sulfate and the majority of the heavy metals started to decrease rapidly with progressive liquid-to-solid ratio (L/S), the ecotoxic hazardous elements antimony (Sb) and vanadium (V) behaved differently. To unravel these unusual release behaviors and the oxyanion-formation of Sb and V we will apply HERFD-XANES spectroscopy to analyze their chemical state. KW - Bottom ash KW - Antimony KW - Vanadium KW - XANES PY - 2023 DO - https://doi.org/10.15151/ESRF-ES-1020936484 PB - European synchroton Radiation Facility ESRF CY - Grenoble AN - OPUS4-56875 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Woydt, Mathias A1 - Scholz, Christian A1 - Manier, Charles-Alix A1 - Brückner, A. A1 - Weihnacht, V. T1 - Slip-rolling resistance of ta-C and a-C coatings up to 3,000 MPa of maximum Hertzian contact pressure N2 - The slip-rolling resistances of hard and stiff thin films under high Hertzian contact pressures can be improved by optimizing the 'coating/substrate systems'. It is known from former investigations that the so-called 'egg-shell' effect is no general hindrance for high slip-rolling resistance of thin hard coatings. The coating stability depends more on specific deposition process and coating/substrate interface design. In this article it is experimentally shown, that pure amorphous carbon thin films with hardness between 15 and 63 GPa can be slip-rolling resistant several million load cycles under a maximum Hertzian contact pressures of up to 3.0 GPa. Whereas all coatings were stable up to 10 million load cycles in paraffin oil at room temperature, reduced coating lifetime was found in SAE 0W-30 engine oil at 120°C. It was shown how the coating hardness and the initial coating surface roughness influence the running-in process and coating lifetime. No clear correlation between coating hardness and coating lifetime could be observed, but friction coefficients seem to be reduced with higher coating hardness. Very low friction down to ~0.03 in unmodified engine oils was found for the hardest ta-C film.------------------------------------------------------------------------------------------------------------------------------------------------ Die Wälzbeständigkeit von harten und steifen Dünnschichten unter hohen Hertzschen Kontaktpressungen kann durch die Optimierung des 'Beschichtung/Substrat Systems' deutlich verbessert werden. Aus vorangegangenen Untersuchungen ist bekannt, dass der so genannte 'Eierschaleneffekt' kein generelles Hindernis für eine hohe Wälzbeständigkeit für harte Dünnschichten darstellen muss. Die Stabilität der Beschichtungen hängt vielmehr von dem spezifischen Prozessparametern und dem Schicht/Substrat Grenzflächendesign ab. In diesem Artikel wird experimentell nachgewiesen, dass reine amorphe Kohlenstoffdünnschichten mit Härtewerten zwischen 15 und 63 GPa für mehrere Millionen Lastzyklen unter maximalen Hertzschen Kontaktpressungen bis 3.0 GPa überrollbeständig sein können. Während alle Beschichtungen bis 10 Millionen Lastzyklen in Paraffinöl bei Raumtemperatur keine Defekte aufweisen wurde unter Verwendung eines SAE 0W-30 Motorenöls bei 120°C eine Verringerung der Überrollbeständigkeit nachgewiesen. Es wurde nachgewiesen, wie die Schichthärte und ursprüngliche Oberflächenrauheit der Beschichtung den Einlaufprozess und die Lebensdauer beeinflussen. Es konnte keine offensichtliche Korrelation zwischen Schichthärte und Lebensdauer festgestellt werden, allerdings wurde eine scheinbare Reduktion des Reibwertes mit steigender Schichthärte beobachtet werden. Dabei zeigte die härteste ta-C Schicht unter Verwendung des Motorenöls sehr geringe Reibwerte mit ~0.03. KW - ta-C KW - a-C KW - Friction KW - Wear KW - Slip-rolling KW - Rolling contact fatigue KW - Reibung KW - Verschleiß KW - Wälzen KW - Rollkontaktermüdung PY - 2012 DO - https://doi.org/10.1002/mawe.201200956 SN - 0933-5137 SN - 1521-4052 VL - 43 IS - 12 SP - 1019 EP - 1028 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-27602 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Woydt, Mathias A1 - Scholz, Christian ED - Beswick, J.M. T1 - Slip-rolling resistance of alternative steels under high contact pressures in engine oils N2 - The inevitable increase of torque or load, because of lightweight approaches, pushes the oil-film temperatures on the teeth flanks of gears above 200°C, and requires alloys with higher strength and toughness properties. Furthermore, the real temperature on surfaces during the physical vapor deposition (PVD) or chemical vapor deposition (CVD) of thin films can exceed the annealing temperature of the state-of-the-art bearing and gear materials, such as AISI 52100 (1.3505), 16MnCr5 (1.7131), 21NiCrMo (1.6523), and 30CrMoV9 (1.7707). Such trends call for slip-rolling-resistant, alternative alloys suited for contact stresses above P0max of >2.2 GPa. The tribological profile under slip-rolling conditions at 120°C in a factory engine oil (SAE 0W-30, ACEA A3/B4, ν120°C = 5.33 mPa, HTHS150°C = 3.0 mPa) until 10 × 106 load cycles between P0max of 2.25 GPa to 3.92 GPa of uncoated 100Cr6 (1.3505, “PBQ”), 102Cr6 (1.2067), Cronidur 30 (1.4108, DESU), 45SiCrMo6 (1.8062, CVEM), 40SiNiCrMo1 [vacuum arc remelting (VAR)], CSS-42L (AMS 5932, vacuum induction melting (VIM)-VAR, and carburized), 36NiCrMoV1-5-7 (CAB), ASP2012 (ASP), and 20MnCr5 (1.7131, carburized) was established in twin disk machines (Amsler-type and 2Disk). The present benchmark illuminates the tribological impact of uncoated bearing steels in comparison to uncoated alternative steel alloys on friction, wear and slip-rolling resistance, as well as load carrying capacity. Iron-based steel alloyed with silicon or molybdenum reduces alloying costs and avoids thermo-chemical treatments. This benchmark suggests considering an extension to fracture toughness from hardness and strength as a relevant property for slip-rolling alloys. If slip-rolling resistant, the wear rates of the metallurgical different steels were more or less within one order of magnitude, but the influence of increasing contact stresses on the tribological profile differed significantly. KW - Slip rolling KW - Bearing steel KW - High toughness steel KW - Silicon KW - Molybdenum KW - Rolling KW - contact fatigue KW - High contact pressure KW - Low friction PY - 2015 SN - 978-0-8031-7605-8 DO - https://doi.org/10.1520/STP158020140018 SN - 2160-2050 N1 - Serientitel: ASTM International - Selected Technical Papers (STP) – Series title: ASTM International - Selected Technical Papers (STP) VL - 1580 SP - 210 EP - 238 AN - OPUS4-33121 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scholz, Christian A1 - Woydt, Mathias A1 - Mohrbacher, H. ED - Mohrbacher, H. T1 - Slip-rolling resistance and load carrying capacity of 36NiCrMoV1-5-7 steel N2 - The approaching CO2 targets have now enforced automotive OEMs to engage R&D efforts also in powertrain to reduce friction, increase lifetime properties, and load carrying capacities of running systems. Martensitic steels such as 36NiCrMoV1-5-7 have a great potential to be used in automotive powertrain applications due to its favorable mechanical properties. In order to realize lightweight strategies, it is essential that steels with improved fracture toughness values and higher annealing temperatures with regard to higher contact pressures and possible thin film coating application be considered. State-of-the-art steels, like 16MnCr5, 21NiCrMo, 30CrMoV9, and 100Cr6 are not able to sustain a further increase in torque or load during operating time as well as annealing effects under higher oil or deposition temperatures. Therefore, the recent research on the slip-rolling resistance, frictional, and wear behavior of steels such as 36NiCrMoV1-5-7, Cronidur 30 (AMS 5898), 20MnCr5 (SAE 4820 or 5120), and 100Cr6H (SAE E52100) showed that possible lean alloying concept alternatives with promising performance characteristics are already available. T2 - 2nd International symposium on fundamentals and applications of Mo and Nb alloying in high performance steels CY - Jeju Island, South Korea DA - 24.04.2013 KW - Molybdenum KW - Steel KW - Slip-rolling resistance KW - High contact pressure KW - Oil PY - 2015 SN - 978-0-692-34620-4 DO - https://doi.org/10.1520/MPC20130022 SN - 2165-3992 VL - 2 SP - 191 EP - 203 AN - OPUS4-32668 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scholz, Christian A1 - Wäsche, Rolf ED - Bartz, Wilfried J. T1 - Effect of sliding speed and relative humidity on the tribological behavior of ceramic and polymer materials T2 - 19th International colloquium Tribology - Industrial and automotive lubrication CY - Stuttgart/Ostfildern, Germany DA - 2014-01-21 PY - 2014 SN - 978-3-943563-10-8 SP - Paper 08_11_Scholz_Man, 1 EP - 6 CY - Stuttgart/Ostfildern AN - OPUS4-31743 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -