TY - CONF A1 - Wäsche, Rolf T1 - Tribological behaviour of polyurethane under oscillating sliding conditions against cast iron T2 - 18. Int. Colloq. Tribology - Industrial and Automotive Lubrication CY - Ostfildern, Germany DA - 2012-01-10 PY - 2012 AN - OPUS4-25343 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kovalev, Alexander A1 - Hartelt, Manfred A1 - Spaltmann, Dirk A1 - Wäsche, Rolf A1 - Woydt, Mathias T1 - Zero wear (Null Verschleiß) N2 - Während des Gleitreibens auftretende, plastische Deformationen im oberen Bereich der Kontaktspitzen werden als „Null-Verschleiß“ bezeichnet. Um diesen zu quantifizieren, werden in dieser Arbeit statt der üblichen, statistischen Rauheitsparameter die Flächen solcher Kontaktspitzenbefrachtet. Dabei liegen diesen Befrachtungen AFM-Bilder von realen Oberflächentopografien auf der Mikro-/Nanoskala als Ausgangspunkt für die Simulationen zugrunde. In den Simulationen wird berücksichtigt, dass die Flächen während der Gleitreibung in den Kontaktspitzen elastisch und plastisch verformt werden können. Ebenso wird der Effekt des Einsatzhärtens in die Befrachtungen eingeschlossen. Die Ergebnisse der Computersimulation stellen einen Weg zur Untersuchung der Reibkräfte zu Beginn des EinlaufVorgangs dar, insbesondere dann, wenn sich dabei die wahre Kontaktfläche verändert hat. Die Ergebnisse der Simulation belegen klar, dass das Vorliegen von „Null-Verschleiß“ stark von der Veränderung der Oberfläche abhängt und nicht von der Erzeugung von Verschleißpartikel begleitet wird. N2 - Recent developments in contact mechanics and microfribology have shown that it is very important to study surface modification effects for quantification of „Zero wear“ (plastic deformation of upper parts of asperities) during sliding friction. The present work considers experimental and Simulation data on the Formation of elastic and plastic contact areas during sliding friction on rough surfaces. The Simulation of discrete contact was carried out using as a source the AFMimages of real surface topography at micro/nanoscale. The approach for quantification of „zero wear“, proposed here, is not using common Statistical Parameters of roughness, but it considers contact areas on asperities. In these areas some regions are undergoing plastic deformation which influences surface Transformation during sliding friction. Also, the workhardening effect was taken into account in the Simulation of sliding friction. This enabled a rnore successful fit of experimental data. The results obtained of the Computer simulations will provide a way of studying friction force at the initial stage of the running-in process. T2 - 53. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß CY - Göttingen, Germany DA - 24.09.2012 PY - 2012 SN - 978-3-00-039201-6 VL - II SP - 43/1 EP - 43/13 CY - Aachen AN - OPUS4-26640 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scholz, Christian A1 - Wäsche, Rolf T1 - Stick-slip and wear behavior of ceramic and polymer materials under reciprocating sliding conditions N2 - In many technical applications not only the actual friction coefficient is of importance, but rather the constancy relevant for the functionality. Due to inconstant ffiction values, positioning processes can be substantially influenced as well as vibrations can be induced. The appearance of this tribological effect, named stick-slip, depends on different factors such as sliding speed, relative humidity and ambient temperature occurring primarily after long operating periods. Beside ambient conditions the choice of materials in contact is the main influencing factor of an inconstant coefficient of friction during operating. Certain polymers are well known for their stick-slip tendencies in technical applications. These are on the one hand different modifications of PTFE (polytetrafluoroethylene) reinforced with glass fibers, bronze or graphite and on the other hand thermoplastics such as PE (polyester) or Pf (polyimide). The difference between static and dynamic values of the ffiction force is decisive for stick-slip phenomena. Furthermore, the stick-slip tendency of polymers strongly depends on the elastic material properties. Main softening material areas, which can be found in the contact, represent particularly vulnerable areas. The high friction value in the contact area decreases in most cases by increasing sliding speeds. However, beside polymers ceramic materials can also offer tendencies to stick-slip motion. Klaffke et al. already investigated the influence of ceramic materials on the stick-slip behavior in. T2 - WTC 2013 - 5th World tribology congress CY - Torino, Italy DA - 08.09.2013 KW - Stick-slip KW - Sliding speed KW - Polymers KW - Ceramics KW - Humidity PY - 2013 SP - 1 EP - 4 AN - OPUS4-29091 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kovalev, Alexander A1 - Hartelt, Manfred A1 - Spaltmann, Dirk A1 - Wäsche, Rolf A1 - Woydt, Mathias T1 - Zero wear (Null Verschleiß) KW - Reibung KW - Null-Verschleiß KW - Rauhigkeit KW - Kontaktmechanik KW - Modellierung KW - DLC KW - Friction KW - Zero-wear KW - Roughness KW - Contact mechanics KW - Simulation PY - 2013 SN - 0724-3472 VL - 60 IS - 2 SP - 5 EP - 12 PB - Expert Verlag CY - Renningen AN - OPUS4-28979 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wäsche, Rolf T1 - Aiming at zero wear - Where are we right now? T2 - International Conference on Industrial Tribology (ICIT 2012) CY - Pune, India DA - 2012-12-07 PY - 2012 AN - OPUS4-27364 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hartelt, Manfred A1 - Cappella, Brunero A1 - Wäsche, Rolf T1 - Verschleißbestimmung im nm-Bereich N2 - Die Verschleißbeträge können im nm-Bereich quantifiziert werden durch die Berechnung eines Mittelwert-Profils. Grundlage dieser Berechnung ist die hochauflösende Erfassung der 3D-Topographiedaten, die tribologisch beanspruchte und nichtbeanspruchte Oberflächenbereiche gleichermaßen beinhalten. Ein bestimmtes Messverfahren (taktil oder optisch) wird nicht favorisiert. Die vertikale Auflösung des Messverfahrens sollte im nm-Bereich liegen. N2 - The wear rates can be quantified in the nm range by calculating a mean profile. Based on this calculation is the high-resolution recording of the 3D topography data containing tribologically worn and unworn surface areas alike. A specific measurement method (tactile or visual) is not favored. The vertical resolution of the measurement process should be in the nm range. T2 - 54. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß - Forschung und praktische Anwendungen CY - Göttingen, Germany DA - 30.09.2013 PY - 2013 SN - 978-3-00-022603-8 VL - I SP - 31/1 EP - 31/10 AN - OPUS4-29640 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Klaffke, Dieter A1 - Wäsche, Rolf ED - Franek, F. T1 - Friction and wear behaviour of ceramic SiC-TiC-TiB2 composites under unlubricated oscillating sliding conditions T2 - 2nd World Tribology Congress ; 2nd WTC 2001 CY - Vienna, Austria DA - 2001-09-03 KW - Silicon carbide KW - Titanium carbide KW - Titanium diboride KW - Alumina KW - Oscillating sliding KW - Humidity PY - 2001 SN - 3-901657-07-X SP - 140 PB - ÖTG CY - Wien AN - OPUS4-1172 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Klaffke, Dieter A1 - Wäsche, Rolf T1 - Friction and wear testing can steer the development of ceramic tribo materials T2 - 2nd World Tribology Congress ; 2nd WTC 2001 CY - Vienna, Austria DA - 2001-09-03 KW - Friction KW - Wear quantities KW - Humidity KW - Ball-on-disk KW - Wear particles PY - 2001 SN - 3-901657-09-6 SP - 141 PB - ÖTG CY - Vienna AN - OPUS4-1152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klaffke, Dieter A1 - Wäsche, Rolf T1 - Tribological Performance of SiC and TiB2 sliding against SiC and Al2O3 T2 - 10th Nordic Symposium on Tribology ; 10th Nordtrib 2002 CY - Stockholm, Sweden DA - 2002-06-09 PY - 2002 SP - 1(?) EP - 10(?) PB - Royal Institute of Technology CY - Stockholm AN - OPUS4-1386 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klaffke, Dieter A1 - Yarim, Rasim A1 - Wäsche, Rolf T1 - Effect of pre-oxidation on friction and wear behaviour of a SiC-TiC-TiB2 composite T2 - 10th Nordic Symposium on Tribology ; 10th Nordtrib 2002 CY - Stockholm, Sweden DA - 2002-06-09 PY - 2002 SP - 1 EP - 10(?) PB - Royal Institute of Technology CY - Stockholm AN - OPUS4-1387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wäsche, Rolf A1 - Steinborn, Gabriele A1 - Klaffke, Dieter ED - Somiya, S. T1 - Gas pressure sintering of SiCp-alumina composites made by gelcasting and their tribological properties N2 - COMPOSITE MATERIALS OF A 99.7 % ALPHA-ALUMINA MATRIX WITH PLATELETS OF SILICON CARBIDE (SICP) HAVE BEEN PREPARED BY GELCASTING. DENSIFICATION WAS CARRIED OUT BY GAS-PRESSURE SINTERING WITHOUT FURTHER SINTERING AIDS. FIVE DIFFERENT COMPOSITIONS WITH 0, 5, 10, 15, AND 20 VOL.% SICP RESP. HAVE BEEN INVESTIGATED AND TRIBOLOGICAL PROPERTIES WERE CHARACTERIZED. INCREASING AMOUNT OF SICP AS RIGID PARTICLES IN THE FINE GRAINED MATRIX COMPLICATE THE DENSIFICATION PROCESS. WITH THE APPLICATION OF 50 BAR AR PRESSURE DURING THE FINAL SINTERING STEP AT A TEMPERATURE OF 1700 DEGREE C THE DENSITY OF THE SAMPLES COULD BE INCREASED BY 3-5%. INVESTIGATION OF THE TRIBOLOGICAL PROPERTIES AGAINST STEEL AS A COUNTERBODY UNDER UNLUBRICATED OSCILLATING SLIDING CONDITIONS SHOWED A HIGH COEFFICIENT OF FRICTION AND AN INCREASING WEAR RATE UP TO A SICP CONTENT OF 10 VOL. % . AT 15 AND 20 VOL. % SICP RESP. BOTH THE COEFFICIENT OF FRICTION AND THE COEFFICIENT OF WEAR DROP DOWN. T2 - 3rd IUMRS International Conference on Advanced Materials (ICAM) CY - Tokyo, Japan DA - 1993-08-31 PY - 1994 SN - 0-444-81993-2 N1 - Serientitel: Transactions of the Materials Research Society of Japan – Series title: Transactions of the Materials Research Society of Japan IS - 16B SP - 791 EP - 794 PB - Elsevier CY - Amsterdam AN - OPUS4-1433 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Steinborn, Gabriele T1 - Characterisation of the secondary properties of alumina - measuring the isoelectric point by a streaming potential method PY - 1997 SN - 0173-9913 SN - 0196-6219 VL - 74 IS - 5 SP - 235 EP - 239 PB - Göller CY - Baden-Baden AN - OPUS4-1434 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Steinborn, Gabriele T1 - Influence of Slip Viscosity on the Mechanical Properties of High Purity Alumina made by Gelcasting KW - High purity alumina KW - Gelcasting KW - Solid content KW - Viscosity KW - Deairing KW - Bending strenght KW - Microstructure KW - Computertomography KW - Defect type PY - 1997 SN - 1013-9826 VL - 132 SP - 374 EP - 377 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-1435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Abe, H. A1 - Naito, M. A1 - Hackley, V. A1 - Hotta, Y. T1 - Influence of particle size and solid loading on the determination of the isoelectric point (IEP) of ceramics powders by different methods N2 - The isoelectric point is a material property for the characterization of acid-base behavior of the powder surface. The IEP of two alumina powders (AKP-30, Grade A) with different particle size characteristics in aqueous suspension has been determined by colloid vibration current (CVI) and particle charge detection (PCD) methods in moderately concentrated suspensions in order to qualify these methods for a future standardization. The solid loading of the suspensions were 1 and 5 vol%. The comparison of the IEP determined by PCD and CVI was in good agreement. However, the solid loading dependence of IEP and a large IEP hysteresis (at 1 vol%) were observed, which do not allow a proper determination of the IEP. The recording of the potential curve and therfore the determination of the IEP with CVI was difficult for the suspension of Grade A powder due to formation of agglomerates at pH values near the pHIEP. T2 - 7th Euro Ceramics - Conference and Exhibition of the European Ceramic Society (ECerS) CY - Brugge, Belgium DA - 2001-09-09 KW - Isoelectric point (IEP) KW - Alumina powder KW - Particle charge detection (PCD) KW - Colloid vibration current (CVI) PY - 2002 UR - http://ois.nist.gov/nistpubs/technipubs/recent/search.cfm?dbibid=9289 DO - https://doi.org/10.4028/www.scientific.net/KEM.206-213.3 SN - 1013-9826 VL - 206-213 SP - 3 EP - 6 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-1437 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -