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 - TY - GEN A1 - Yarim, Rasim A1 - Wäsche, Rolf A1 - Woydt, Mathias ED - Franek, F. T1 - Wear Behaviour of SiC-TiC-TiB2 Ceramic Composites Sliding against SiC up to 800°C and 2m/s T2 - 2nd World Tribology Congress ; 2nd WTC 2001 CY - Vienna, Austria DA - 2001-09-03 KW - Dry sliding KW - Tribochemistry KW - Silicon carbide KW - Titanium carbide KW - Titanium boride KW - High temperature KW - Ceramic composites PY - 2001 SN - 3-901657-07-X SP - 1(?) EP - 4(?) PB - ÖTG CY - Wien AN - OPUS4-1438 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wäsche, Rolf A1 - Klaffke, Dieter ED - Andersson, P. T1 - Tribological Behaviour of Multiphase Ceramic Composites in the System Si-Ti-B-C Containing Free Carbon T2 - 9th Nordic Symposium on Tribology ; 9th NORDTRIB 2000 CY - Porvoo, Finland DA - 2000-06-11 PY - 2000 SN - 951-38-5276-8 SN - 0357-9387 N1 - Serientitel: VTT Symposium – Series title: VTT Symposium VL - 1 IS - 200 SP - 186 EP - 195 PB - VTT, Technical Research Centre of Finland CY - Espoo AN - OPUS4-1439 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Klaffke, Dieter T1 - Ceramic particulate composites in the system SiC-TiC-TiB2 sliding against SiC and Al2O3 under water N2 - The tribological behaviour of SiC, SiC-TiC and SiC-TiC-TiB2 was determined in oscillating sliding against SiC and -Al2O3 in water at room temperature. The tribo-systems with the composite materials containing TiC and TiB2 differ significantly from the systems with the single phase SiC: The wear is reduced and the friction is increased. The wear reduction up to a factor of 10 is mainly due to the formation of an oxide film containing titanium oxides which is soft, stable in water and well adhering to the bulk material. This oxide film is transferred to the alumina ball but not to the silicon carbide ball. KW - Silicon carbide KW - Titanium carbide KW - Titanium boride KW - Ceramic KW - Particulate composites KW - Oscillating sliding KW - Water lubrication KW - Friction KW - Wear PY - 1999 DO - https://doi.org/10.1016/S0301-679X(99)00033-X SN - 0301-679X VL - 32 IS - 4 SP - 197 EP - 206 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-1440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wäsche, Rolf A1 - Naito, M. ED - Puri, V. ED - Adair, J. ED - Knobloch, C. ED - Huang, C. T1 - Electrokinetic Characterization of Aqueous Ceramic Suspensions T2 - Fine Powder Processing Conference '99 CY - State University, PA, USA DA - 1999-09-20 KW - Meßverfahren KW - Zeta Potenzial KW - Hochleistungskeramik PY - 1999 SP - 177 EP - 183 AN - OPUS4-1441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Klaffke, Dieter A1 - Czichos, Horst T1 - Wear behaviour of i-carbon coatings PY - 1992 SN - 0043-1648 VL - 153 SP - 149 EP - 162 PB - Elsevier CY - Amsterdam AN - OPUS4-1428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Steinborn, Gabriele T1 - Influence of the Dispersants in Gelcasting of Nanosized TiN PY - 1997 SN - 0955-2219 SN - 1873-619X IS - 17 SP - 421 EP - 426 PB - Elsevier CY - Oxford AN - OPUS4-1429 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Naito, M. A1 - Hackley, V.A. T1 - Experimental study on zeta potential and streaming potential of advanced ceramic powders N2 - Zeta potential as measured with the electrokinetic sonic amplitude (ESA) method has been compared to streaming potential as measured with the particle charge detection (PCD) method. The measurements have been carried out on identical suspensions of a-Al2O3, SiC and Si3N4 with a solids volume fraction of 1% and 10%. Zeta potential and streaming potential are related by a linear function. The correlation coefficients for this relationship are better than 0.99 for the suspensions with 1% solids loading. For the suspensions with 10% solids loading, correlation coefficients are slightly lower due to the influence of increasing viscosity. Regardless of lower correlation at the higher solids loading, the isoelectric pH is constant within the limits of accuracy of the pH measurements. KW - Zeta potential KW - Streaming potential KW - Ceramic powders KW - Correlation of measurement PY - 2002 DO - https://doi.org/10.1016/S0032-5910(01)00462-4 SN - 0032-5910 SN - 1873-328X VL - 123 SP - 275 EP - 281 PB - Elsevier CY - Amsterdam AN - OPUS4-1430 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf T1 - Keramische Supraleiter - Kristallstruktur, Gefüge und Eigenschaften PY - 1988 SN - 0340-7551 VL - 18 IS - 2 SP - 128 EP - 133 PB - Bundesanstalt für Materialprüfung CY - Berlin AN - OPUS4-1431 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf T1 - Feste Schmierstoffe für hohe Temperaturen - Eine Literaturübersicht PY - 1989 SN - 0724-3472 VL - 36 IS - 3 SP - 145 EP - 151 PB - Expert Verlag CY - Renningen AN - OPUS4-1432 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kautek, Wolfgang A1 - Rudolph, Pascale A1 - Brzezinka, Klaus-Werner A1 - Wäsche, Rolf ED - Meunier, M. T1 - Physical chemistry of the femtosecond and nanosecond laser-material-interaction with SiC and a SiC-TiC-TiB2 composite ceramic compound N2 - The interaction of nanosecond laser pulses in the ultraviolet wavelength range and femtosecond laser pulses in the near-infrared region with the direct semiconductor SiC and the composite compound SiC-TiC-TiB2 was investigated in respect to resulting physicochemical processes. Surface analytical techniques, such as XPS, µ-Raman, and EDX were used to identify the chemical changes between untreated and laser-treated areas. Single-pulse irradiation led to material modifications in the condensed state in most instances. Multi-pulse results differed depending on the pulse duration. In the nanosecond case, melting of the surface and redeposited material (debris) were observed. With femtosecond pulses instead, only negligible melting and few debris could be detected. Additionally, periodic structures (ripples) appeared, with parallel orientation and in most cases two different periodicities for a particular material. Laser ablation of all the studied compound materials exhibited preferential ablation of the lighter component elements. Crystal structure changes of the irradiated surface were observed as a consequence of laser-induced melting and resolidification. An oxidation process interfered with all this processes so that unstoichiometric oxides were formed. T2 - Symposium D - European Materials Research Society CY - Strasbourg, France DA - 2002-06-18 PY - 2002 UR - http://www.emrs-strasbourg.com/files/pdf/2002_SPRING/02_Prog_Dv2.pdf N1 - Serientitel: Applied surface science – Series title: Applied surface science VL - 208/209.2003,1 IS - 1 SP - 1 PB - Elsevier CY - Amsterdam AN - OPUS4-1732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steinborn, Gabriele A1 - Wäsche, Rolf A1 - Reichel, U. T1 - Fabrication of porous ceramics made from nano sized alumina powder by gelcasting N2 - The gelcasting process was used for manufacturing porous ceramic bodies from nano sized powders. 3 different powders with specific surface areas between 12 and 30 m²/g were used. Solid content of the corresponding slurries was dependent on the milling procedure and the use of a suitable dispersant. For bimodal GradeA powder solid content was as high as 58 vol%. For sintering temperatures between 1250 and 1600°C the porosity varied between 45 and 20%, whereas the pore radii varied between 50 and 91nm. The grain size of crystallites in the sintered microstructures was about 1um. The reflection ratio for visible light increased in comparison to a reference sample made from conventional powder from 0.8 to 0.95 in the wavelenght range around 400nm. T2 - 2nd International Conference on Shaping of Advanced Ceramics CY - Gent, Belgium DA - 2002-10-24 PY - 2002 SP - 103 EP - 108 AN - OPUS4-1813 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wäsche, Rolf A1 - Suchantke, Christian A1 - Yarim, Rasim ED - Schulte, K. ED - Kainer, K. T1 - Sintern von Verbundwerkstoffen im System SiC-TiC-TiB2 T2 - 12. Tagung "Verbundwerkstoffe und Werkstoffverbunde" CY - Hamburg, Deutschland DA - 1999-10-05 KW - Sintern KW - Verbundwerkstoffe KW - Thermochemische Analyse PY - 1999 SN - 3-527-29967-X SP - 189 EP - 194 PB - Wiley-VCH CY - Weinheim AN - OPUS4-720 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Klaffke, Dieter T1 - High temperature tribological behaviour of particulate composites in the system SiC-TiC-TiB2 during dry oscillating sliding KW - Ceramic Composites KW - High temperatures KW - Tribo-oxidation KW - Dry-slidins KW - Friction KW - Wear PY - 1999 SN - 1225-9381 VL - 5 IS - 2 SP - 155 EP - 161 PB - Han'guk-Seramik-Hakhoe CY - Seoul AN - OPUS4-761 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Klaffke, Dieter A1 - Wäsche, Rolf ED - Schulte, K. ED - Kainer, K. T1 - Tribologische Prüfungen als begleitende Maßnahme zur Entwicklung von keramischen Tribowerkstoffen T2 - 12. Tagung "Verbundwerkstoffe und Werkstoffverbunde" CY - Hamburg, Deutschland DA - 1999-10-05 KW - Tribologie KW - Reibung KW - Verschleiß PY - 1999 SN - 3-527-29967-X SP - 423 EP - 428 PB - Wiley-VCH CY - Weinheim AN - OPUS4-723 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Naito, M. A1 - Jahanmir, S. T1 - TWA 27 Characterization Methods for Ceramic Powders and Green Bodies KW - Standardisierung KW - Keramische Pulver KW - Grünkörper PY - 2000 SN - 1016-2178 IS - 23 SP - 21 EP - 27 PB - National Institute of Standards and Technology AN - OPUS4-979 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Klaffke, Dieter T1 - Wear of multiphase SiC based ceramic composites containing free carbon N2 - Ceramics are of increasing interest for application in many branches of technique. In order to improve the tribological performance of ceramic materials, composites on the basis of silicon carbide with different amounts of titanium carbide, boron carbide, titanium diboride and free carbon in the form of graphite were manufactured by a reaction sintering process. The friction and wear behaviour of these composites was investigated with oscillating sliding motion in unlubricated tests at room temperature on different levels of relative humidity. Additional tests were performed under water lubrication, revealing the superior behaviour of composites for special test conditions. A major influence of the free carbon on friction or wear behaviour was not observed. The tribological behaviour in air as well as under water is mainly dependant on the amount of titanium phases. KW - Siliziumkarbid KW - Verbundwerkstoffe KW - Tribooxidation KW - Silicon carbide KW - Ceramic composites KW - Humidity water KW - Lubrication PY - 2001 DO - https://doi.org/10.1016/S0043-1648(01)00566-X SN - 0043-1648 VL - 249 SP - 220 EP - 228 PB - Elsevier CY - Amsterdam AN - OPUS4-900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Wäsche, Rolf A1 - Habig, Karl-Heinz T1 - Physikalisch-chemische Grundlagen der Feststoffschmierung - Literaturübersicht - N2 - Die für einen erfolgreichen Einsatz von Festschmierstoffen zur Minderung von Reibung und Verschleiß systembestimmender Parameter wie Last, Geschwindigkeit, Temperatur, umgebende Atmosphäre, Filmbildung und -haltung sowie die Anwendungstechnologien werden dargestellt, ferner Modellvorstellungen zum Verschleißverhalten von Festschmierstoffen im Hinblick auf konkrete Anwendungsfälle diskutiert. T3 - BAM Forschungsberichtreihe - 158 KW - Festschmierstoff KW - Transferschmierung KW - Hohe Temperaturen KW - Graphit KW - Reibung KW - Verschleißmodelle KW - gebundene Filme KW - Synergieeffekte PY - 1989 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-2921 SN - 978-3-88314-889-X SN - 0938-5533 VL - 158 SP - 1 EP - 112 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-292 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Wäsche, Rolf A1 - Köse, Fatma T1 - Einfluß der Verfahrensparameter beim Gelcasting auf die Entstehung bruchauslösender Gefügefehler in hochreinen Aluminiumoxidkeramiken N2 - Es wird die Untersuchung des Entlüftungsvorgangs in Keramikschlickern beschrieben, die Teil des Gelcastingprozesses zur Herstellung hochfester Aluminiumoxidkeramiken sind. Ziel der Untersuchung war es, den Einfluss von Viskosität und Entlüftungszeit als prozessvariablen auf die Entstehung von bruchauslösenden Fehlern im Gefüge zu verdeutlichen. T3 - BAM Forschungsberichtreihe - 221 PY - 1997 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-2294 SN - 978-3-89429-036-4 SN - 0938-5533 VL - 221 SP - 1 EP - 54 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-229 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dörfel, Ilona A1 - Wäsche, Rolf A1 - Rabe, Torsten A1 - Steinborn, Gabriele T1 - Tribological Induced Microstructural Changes in Subsurface Layers of Si3N4-Based Materials KW - Tribologie PY - 1994 SN - 1013-9826 VL - 89-91 SP - 763 EP - 767 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klaffke, Dieter A1 - Hartelt, Manfred A1 - Wäsche, Rolf ED - Bartz, Wilfried J. T1 - Non-Oxide Ceramics as Tribo Materials - Analysis of Wear Mechanisms under Oscillating Sliding Conditions in Various Atmospheres T2 - 12th International Colloquium Tribology CY - Esslingen, Germany DA - 2000-01-11 KW - Tribologie PY - 2000 SN - 3-924813-44-2 VL - 3 SP - 1755 EP - 1763 PB - Techn. Akad. Esslingen CY - Ostfildern AN - OPUS4-848 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wäsche, Rolf T1 - Characterisation of tribological interface in low wear magneli type ceramics T2 - International Conference on Characterisation and Control of Interfaces (ICCC 2009) CY - Kurashiki, Japan DA - 2009-09-06 PY - 2009 AN - OPUS4-22871 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wäsche, Rolf A1 - Woydt, Mathias A1 - Rehmer, Birgit ED - Ewsuk, K. ED - Naito, M. ED - Kakeshita, T. ED - Kirihara, S. ED - Uematsu, K. ED - Abe, H. T1 - Characterization of the tribological interface in low wear Magneli type ceramics N2 - The tribological behaviour under dry sliding conditions of Magneli phase Ti4O7 and e-phase Ti2Cr2O7 with α-alumina as a sliding partner has been characterised at room temperature by oscillating sliding. The mechanical properties as well as Vickers hardness measurements do not reveal big differences between the materials, and 4-point bending strengths are around 200 MPa for both materials. Although the friction coefficients are in the medium range of 0.6 and do not differ much between the materials, the wear behaviour is very different. At room temperature, the wear coefficient of Ti2O7 is strongly dependent on relative humidity, and wear is highest under dry conditions when relative humidity is low as it is typically found for many ceramic materials. Ti2Cr2O7 shows remarkably different wear behaviour with the lowest wear in dry conditions. The measured coefficients of wear at low relative humidity of 4% are more than 2 orders of magnitude lower than those for Ti2O7. T2 - 3rd International conference on characterization and control of interfaces for high quality advanced materials CY - Kurashiki, Japan DA - 2009-09-06 PY - 2009 SN - 978-0-470-90917-1 VL - 219 SP - 111 EP - 116 PB - John Wiley & Sons CY - Hoboken, New Jersey, USA AN - OPUS4-21842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Salge, T. A1 - Wäsche, Rolf A1 - Hodoroaba, Vasile-Dan T1 - Advanced light element and low energy X-ray analysis of a TiB2 – TiC – SiC ceramic material using EDS spectrum imaging N2 - The accurate EDS microanalysis of light elements such as boron and carbon by spectrum imaging will be demonstrated using a sintered hard ceramic material composed of the three major phases titanium boride (TiB2), titanium carbide (TiC), silicon carbide (SiC) and minor phases, sub-μm in size. The combination of these three materials leads to improved mechanical and tribological properties. Silicon carbide is a material used for mechanical seals. It has the disadvantage of reduced failsafe running functions, causing increased wear when running dry. The added titanium components (TiC and TiB2) improve the failsafe running functions. This technology has already been transferred to industrial applications. KW - EDS KW - Spectrum imaging KW - Ceramic KW - Phase analysis KW - Light elements PY - 2018 UR - https://www.bruker.com/fileadmin/user_upload/8-PDF-Docs/X-rayDiffraction_ElementalAnalysis/Microanalysis_EBSD/LabReports/App_eds_10_LE_keramik_Rev1_1_lores.pdf SP - 1 EP - 5 CY - Berlin AN - OPUS4-44622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wäsche, Rolf T1 - A study on wear particle analysis in lubricated steel-steel contacts T2 - International Tribology Congress/ITC 2015 CY - Tokyo, Japan DA - 2015-09-15 PY - 2015 AN - OPUS4-34324 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hartelt, Manfred A1 - Wäsche, Rolf A1 - Hodoroaba, Vasile-Dan T1 - Verschleißpartikel-Analyse mit Rasterelektronenmikroskopie und energiedispersiver Röntgenspektrometrie im Transmissionsmodus (TSEM/EDX) N2 - Untersucht wurden Verschleißpartikel als elektronen-transparente Proben auf dünnen Trägerfolien mit einem hochauflösendem Rasterelektronenmikroskop und energiedispersiver Röntgenspektrometrie im Transmissionsmodus. Die hohe laterale Auflösung dieser modernen Methoden ermöglicht eine morphologische Charakterisierung der Verschleißpartikel bis in den nm-Bereich. Die hochauflösende Elementanalyse erlaubt eine Interpretation der Zusammensetzung und damit Rückschlüsse auf die Verschleißpartikelbildung. Die tribologischen Untersuchungen sind an einem Modell-Verschleißtribometer nach DIN 51834-2 geschmiert, aber ohne Ölkreislauf, durchgeführt worden. Die Präparation der Verschleißpartikel über eine Entnahme und Übertragung einer geringen Schmierstoffmenge mit einer Mikropipette auf eine TEM-Trägerfolie ist mit einem geringen Aufwand möglich. Der präparative Aufwand ist relativ gering. Das benötigte Schmierstoffvolumen beträgt wenige Mikroliter (0,001ml). Die Untersuchung zeigt die geringe geometrische Größe der Verschleißpartikel und bestätigt indirekt die These der Reaktionsschichtbildung mit einer geringen Schichtdicke, die ständig verschleißt und sich stetig neu bildet. Die beschriebenen Verschleißprozesse sind in der Modell-Verschleiß-Prüfung mit sehr hohen Pressungen am Versuchsbeginn nachweisbar. 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 - I SP - 05/1 EP - 05/10 AN - OPUS4-31528 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Sato, K. A1 - Brandt, Guido A1 - Schmid, Thomas A1 - Sasaki, S. A1 - Woydt, Mathias T1 - Wear behaviour of MgO stabilized zirconia in hot steam environment up to 400°C N2 - Self-mated magnesia stabilized zirconia (Mg-PSZ) ceramic sliding couples have been investigated at 100 N load (P0max= 1324 MPa) in oscillating sliding conditions in different humidity conditions in air and in hot steam. Temperatures have been varied up to 400 °C and pressures up to 6 bars. The results show that the wear behavior of MgO-ZrO2 under high Hertzian contact pressures is strongly dependent on temperature and is similar for both dry oscillating and oscillating in hot steam. However, although the evolution in wear rates on temperature is similar and the wear rates of MgO-ZrO2 plunged above 300 °C in hot steam and air by nearly three orders of magnitude, SEM micrographs revealed in hot steam at 400 °C smooth wear tracks. In contrast, hot steam enhanced the tribochemistry of self-mated alumina couples and reduced wear rates. Hot steam decreased the coefficients of friction of MgO-ZrO2 with increasing temperature, but not the wear rates. KW - Hot steam KW - Zirconia KW - Friction KW - Wear KW - Tribofilm KW - Raman spectroscopy PY - 2019 DO - https://doi.org/10.1016/j.wear.2019.01.047 VL - 426-427 SP - 428 EP - 432 PB - Elsevier B.V. AN - OPUS4-47873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Harsha, A. P. A1 - Wäsche, Rolf A1 - Joyce, T. J. T1 - Wear of biopolymers under reciprocating sliding conditions against different counterfaces N2 - In the present work it was shown the investigation of wear resistance of ultrahigh-molecular weight polyethylene (UHMWPE) and crosslinked polyethylene (XLPE) against different counterfaces. Friction and wear studies were evaluated under dry reciprocating sliding conditions at room temperature. KW - Biopolymers KW - Wear KW - Friction KW - UHMWPE PY - 2019 DO - https://doi.org/10.1002/pen.25239 VL - 59 IS - 11 SP - 2356 EP - 2366 PB - Society of Plastics Engineers AN - OPUS4-49779 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wäsche, Rolf T1 - Analysing wear particles on the nano scale N2 - A novel method for preparation and chracterisation of nano scale wear particles by means of TSEM was presented. The tribological tests were carried out in a lubricated system at a temperature of 80°C. T2 - The 17th Nordic Symposium on Tribology - NORDTRIB 2016 CY - Hämeenlinna, Finland DA - 14.06.2016 KW - Nano scale KW - Wear particles KW - Tribology KW - Steel KW - SEM PY - 2016 AN - OPUS4-38209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Hartelt, Manfred A1 - Hodoroaba, Vasile-Dan T1 - Analysis of nanoscale wear particles from lubricated steel-steel contacts N2 - A new method for sampling wear particles directly from the lubricant reservoir has been developed and applied successfully for analyzing wear particles by high-resolution scanning electron microscopy in transmission mode having coupled energy-dispersive X-ray spectroscopy. The lubricated tribological testing was carried out with fully formulated as well as with non-formulated synthetic base oil. It was possible to analyze individual particles with dimensions as small as about 5–30 nm which are likely the 'primary' wear particles. A majority of the particles, however, are agglomerated and, thus, lead to the formation of larger agglomerates of up to a few micrometers. Chemical analysis led to the conclusion that most of the observed particles generated in formulated oil, especially the larger ones, are composed of the additives of the lubricant oil. In non-formulated base oil, the primary particles are of similar dimensions but contain only iron, chromium and oxygen, but most likely stem from the mating materials. This finding points to the fact that the main wear mechanism under lubricated conditions with fully formulated oil is more like a continuous shearing process rather than a catastrophic failure with the generation of larger primary particles. When the oil is non-formulated, however, several wear mechanisms act simultaneously and the wear rate is increased significantly. Generated larger primary particles are milled down to the nanoscale. When the oil is fully formulated, wear mainly takes places at the additive layer or tribofilm; thus, the steel surface is protected. KW - Particle KW - Wear particle analysis KW - Lubricated contact KW - Bearing steel KW - Nanoscale T-SEM KW - Nanoscale EDX analysis PY - 2015 DO - https://doi.org/10.1007/s11249-015-0534-1 SN - 1023-8883 SN - 1573-2711 VL - 58 IS - 3 SP - 49-1 - 49-10 PB - Springer Science Business Media B.V. CY - Dordrecht AN - OPUS4-33525 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hartelt, Manfred A1 - Wäsche, Rolf A1 - Hodoroaba, Vasile-Dan T1 - Verschleißpartikel-Analyse mit Rasterelektronenmikroskopie und energiedispersiver Röntgenspektrometrie im Transmissionsmodus (TSEM/EDX) N2 - Untersucht wurden Verschleißpartikel als elektronentransparente Proben auf dünnen Trägerfolien mit einem hochauflösendem Rasterelektronenmikroskop und energiedispersiver Röntgenspektrometrie im Transmissionsmodus. Die hohe laterale Auflösung dieser modernen Methoden ermöglicht eine morphologische Charakterisierung der Verschleißpartikel bis in den nm-Bereich. Die hochauflösende Elementanalyse erlaubt eine Interpretation der Zusammensetzung und damit Rückschlüsse auf die Verschleißpartikelbildung. Die tribologischen Untersuchungen sind an einem Modell-Verschleißtribometer nach DIN 51834-2 geschmiert, aber ohne Ölkreislauf, durchgeführt worden. Die Präparation der Verschleißpartikel über eine Entnahme und Übertragung einer geringen Schmierstoffmenge mit einer Mikropipette auf eine TEM-Trägerfolie ist mit einem geringen Aufwand möglich. Der präparative Aufwand ist relativ gering. Das benötigte Schmierstoffvolumen beträgt wenige Mikroliter (0,001 ml). Die Untersuchung zeigt die geringe geometrische Größe der Verschleißpartikel und bestätigt indirekt die These der Reaktionsschichtbildung mit einer geringen Schichtdicke, die ständig verschleißt und sich stetig neu bildet. Die beschriebenen Verschleißprozesse sind in der Modell-Verschleiß-Prüfung mit sehr hohen Pressungen am Versuchsbeginn nachweisbar. KW - Modellverschleißprüfung KW - Verschleißpartikel-Analyse KW - TSEM PY - 2015 SN - 0724-3472 VL - 62 IS - 6 SP - 5 EP - 11 PB - Expert Verlag CY - Renningen AN - OPUS4-35043 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kaltzakorta, O. A1 - Wäsche, Rolf A1 - Hartelt, Manfred A1 - Aginagalde, A. A1 - Tato, W. T1 - Influence of polymer filler on tribological properties of thermoplastic polyurethane under oscillating sliding conditions against cast iron N2 - The tribological behaviour of unfilled thermoplastic polyurethane (TPU) and a polymer sphere filled (TPUG) thermoplastic polyurethane have been studied under oscillating sliding condition against cast iron as a counterpart. In the case of unfilled TPU, the wear mechanisms are dominated by particle detachment and roll formation. In principle, TPUG also showed a similar wear mechanism as that of unfilled TPU; in addition, particle pull-out and delamination are also observed. Wear volume of TPUG was significantly higher than that for the unfilled TPU and this is attributed to the different material removal processes taking place in the material during sliding. The polymer spheres as a filler material deteriorated the wear resistance of TPU because of improper adhesion and bonding of filler in the TPU matrix and therefore it contributed to more wear. In case of TPU the friction behaviour was strongly dependant on the temperature and surface roughness of the counter body. The results showed that below the glass transition temperature higher friction values are observed with higher counter body surface roughness. However, above the glass transition temperature, higher friction values are observed with a smoother surface roughness of the counter body. In case of TPUG, the friction behaviour was not significantly dependent on surface roughness of the counter body. KW - Dry sliding KW - Polymers KW - Cast iron KW - Temperature PY - 2012 DO - https://doi.org/10.1007/s11249-012-0017-6 SN - 1023-8883 SN - 1573-2711 VL - 48 IS - 2 SP - 209 EP - 216 PB - Springer Science Business Media B.V. CY - Dordrecht AN - OPUS4-27272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -