TY - JOUR A1 - Österle, Werner A1 - Dörfel, Ilona A1 - Prietzel, Claudia A1 - Rooch, Heidemarie A1 - Cristol-Bulthé, A.-L. A1 - Defallaix, G. A1 - Desplanques, Y. T1 - A comprehensive microscopic study of third body formation at the interface between a brake pad and brake disc during the final stage of a pin-on-disc test KW - Brake KW - Third body KW - Wear KW - Friction KW - Nano-scale KW - TEM PY - 2009 U6 - https://doi.org/10.1016/j.wear.2008.11.023 SN - 0043-1648 VL - 267 IS - 5-8 SP - 781 EP - 788 PB - Elsevier CY - Amsterdam AN - OPUS4-19450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tasdemir, Z. A1 - Wollschläger, Nicole A1 - Österle, Werner A1 - Leblebici, Y. A1 - Alaca, B. E. T1 - A deep etching mechanism for trench-bridging silicon nanowires N2 - Introducing a single silicon nanowire with a known orientation and dimensions to a specific layout location constitutes a major challenge. The challenge becomes even more formidable, if one chooses to realize the task in a monolithic fashion with an extreme topography, a characteristic of microsystems. The need for such a monolithic integration is fueled by the recent surge in the use of silicon nanowires as functional building blocks in various electromechanical and optoelectronic applications. This challenge is addressed in this work by introducing a top-down, silicon-on-insulator technology. The technology provides a pathway for obtaining well-controlled silicon nanowires along with microstructures up to a three-order-of-magnitude scale difference. A two-step etching process is developed, where the first shallow etch defines a nanoscale protrusion on the wafer surface. After applying a conformal protection on the protrusion, a deep etch step is carried out forming the surrounding microscale features. A minimum nanowire cross-section of 35 nm by 168 nm is demonstrated in the presence of an etch depth of 10 m. All cross-sectional features are characterized via transmission electron microscopy and linked to specific process steps. The technology allows control on all dimensional aspects along with the exact location and orientation of the silicon nanowire. KW - Silicon nanowire KW - Deep reactive ion etching KW - Transmission electron microscopy PY - 2016 U6 - https://doi.org/10.1088/0957-4484/27/9/095303 SN - 0957-4484 SN - 1361-6528 VL - 27 IS - 9 SP - 095303-1 EP - 095303-8 PB - IOP Publishing AN - OPUS4-35789 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hinrichs, R. A1 - Vasconcellos, M.A.Z. A1 - Österle, Werner A1 - Prietzel, Claudia T1 - A TEM snapshot of magnetite formation in brakes: the role of the disc's cast iron graphite lamellae in third body formation N2 - A cross-section sample of the friction film formed on top of a disc during a brake testing procedure against Polymer Matrix Composite pads was made using a Focused Ion Beam (FIB). The FIB-cut sampled the "third body" magnetite layer and the upper part of the cast iron disc containing a graphite flake. Images of the sample examined in a Energy Filtered Transmission Electron Microscope captured an instant view of the important role of the graphite flakes in magnetite formation, where few layer graphene batches interacted with the iron border promoting cracking and oxidation along the graphite–iron interface. The resulting nano-scale interlayer of magnetite and strongly disordered graphite formed a third body which yielded adequate brake performance. KW - Cast iron KW - Carbon KW - Graphite KW - Tribochemistry KW - Electron microscopy PY - 2011 U6 - https://doi.org/10.1016/j.wear.2010.11.008 SN - 0043-1648 VL - 270 IS - 5-6 SP - 365 EP - 370 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-23189 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hinrichs, R. A1 - Zen Vasconcellos, M.A. A1 - Österle, Werner A1 - Prietzel, C. T1 - Amorphization of graphite flakes in gray cast iron under tribological load N2 - A gray cast iron disc, which had been submitted to a heavy duty automotive brake test, was examined with energy filtered transmission electron microscopy. A graphite flake in a convenient angular position showed the shear interaction of graphite layers with the iron matrix in nano-scale resolution. Atomic layers of graphite were wedged into the ferritic bulk, allowing the entrance of oxygen and the subsequent formation of magnetite. The exfoliated few-layer graphene batches deformed heavily when forced into the matrix. When Raman spectra from the disc surface, which show distinctive carbonaceous bands, were compared with Raman spectra from graphite subjected to deformation in a shaker mill with different milling times, it could be seen that the shear stress on the brake surface was much more effective to induce disorder than the milling, where compressive and impact forces had been additionally exerted on the sample. During shear load the high anisotropy of elastic modulus in the graphite crystalline structure and the low adhesion between graphite basal planes allowed the exfoliation of wrinkled few-layer grapheme batches, causing the formation of more defect related Raman bands than the mechanical stress during high-energy milling. KW - Graphite KW - Shear load KW - Amorphization KW - EFTEM KW - Raman spectroscopy PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-469227 SN - 1516-1439 SN - 1980-5373 VL - 21 IS - 4 SP - e20171000, 1 EP - 6 PB - Universidade Federal de São Carlos CY - São Carlos AN - OPUS4-46922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Dmitriev, Andrey A1 - Kloß, Heinz T1 - Assessment of sliding friction of a nanostructured solid lubricant film by numerical simulation with the method of movable cellular automata (MCA) N2 - Tribofilms formed during dry sliding usually exhibit a nanocrystalline structure and complicated composition. In the present study, tribofilms consisting mainly of a solid lubricant, namely graphite nanoparticles, are considered. Systems providing such tribofilms are candidates for anti-friction applications. Since sliding action always leads to mixing of the materials at both sides of the tribological interface, it was of major interest to study the impact of different amounts of a hard constituent, SiC in the considered case, within the soft matrix systematically. Furthermore, the impact of normal pressure was considered. A mechanically mixed layer was observed for the whole range of normal pressures and SiC volume fractions. The calculated coefficient of friction decreased significantly with increasing thickness of this layer but was only marginally affected by SiC volume fraction, which is good news for anti-friction applications. T2 - WTC 2013 - 5th World tribology congress CY - Torino, Italy DA - 08.09.2013 KW - Friction KW - Third body film KW - Numerical simulation KW - Nanostructure PY - 2013 SP - 1 EP - 4 AN - OPUS4-29659 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nebauer, E. A1 - Mai, M. A1 - Würfl, J. A1 - Österle, Werner T1 - Au/Pt/Ti/Pt base contacts to n-InGaP/p+-GaAs for self-passivating HBT ledge structures N2 - Multi-layer ohmic contact systems such as Au/Pt/Ti/Pt on III-V double layers such as n-InGaP/p+-GaAs are of considerable technological relevance, e.g. for heterojunction bipolar transistors. The paper shows that such contacts can be effectively reacted through the InGaP layer and exhibit very good contact resistances (0.1 O mm) to the base layer if the thickness of the first Pt layer is properly matched to the thickness of the contacted InGaP layer. Interdiffusion and phase formation associated with the annealing processes are studied by cross-sectional analytical transmission electron microscopy, thin-film x-ray diffraction and Auger electron spectroscopy depth profiling. Thermal ageing experiments up to 400 °C show good electrical stability. Device related reliability tests do not show any degradation effect related to this novel base contact. PY - 2000 U6 - https://doi.org/10.1088/0268-1242/15/8/306 SN - 0268-1242 SN - 1361-6641 VL - 15 IS - 8 SP - 818 EP - 822 PB - IOP Publ. CY - Bristol AN - OPUS4-2368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senoner, Mathias A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Österle, Werner A1 - Kaiander, I. A1 - Sellin, R.L. A1 - Bimberg, D. T1 - BAM-L002 - A new type of certified reference material for length calibration and testing of lateral resolution in the nanometre range N2 - A new type of test sample for the determination of lateral resolution in surface analysis is presented. The certified reference material BAM-L002 Nanoscale strip pattern for length calibration and testing of lateral resolution is an embedded cross-section of epitaxially grown layers of AlxGa1-xAs and InxGa1-xAs on GaAs substrate. The surface of the sample provides a flat pattern with strip widths of 0.4-500 nm. The combination of gratings, isolated narrow strips and sharp edges of wide strips offers improved possibilities for the calibration of a length scale, the determination of lateral resolution and the optimization of instrument settings. The feasibility of the reference material for an analysis of lateral resolution is demonstrated for SIMS. PY - 2004 U6 - https://doi.org/10.1002/sia.1936 SN - 0142-2421 SN - 1096-9918 VL - 36 SP - 1423 EP - 1426 PB - Wiley CY - Chichester AN - OPUS4-4696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner T1 - Berechnung des Streckgrenzenbeitrags plättchenförmiger Teilchen auf der Grundlage einer quantitativen Gefügeanalyse mit dem TEM PY - 1984 SN - 0032-678X VL - 21 SP - 377 EP - 389 PB - Hanser CY - München AN - OPUS4-2395 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jiao, Feng A1 - Österle, Werner A1 - Portella, Pedro Dolabella A1 - Ziebs, Josef T1 - Biaxial path-dependence of low-cycle fatigue behaviour and microstructure of alloy 800 H at room temperature N2 - Low-cycle fatigue experiments under combined axial-torsional loading have been carried out on alloy 800 H tubular specimens at room temperature. In comparison with proportional loading, an extra cyclic hardening effect produced by nonproportional loading was observed. The microstructure study highlights the fact that the dislocation arrangement under proportional loading is significantly different from that under nonproportional loading. Mechanical twinning was found in specimens cycled under axial loading and nonproportional loading. It is suggested that mechanical twinning depends not only on shear stress but also on normal stress on the plane of maximum shearing. The extra hardening can be interpreted in terms of the deformation microstructure. Fatigue cracking was initiated generally at the specimen surfaces along the plane of maximum shearing, but under nonproportional loading cracks were found also in the bulk of the specimens. Transcrystalline crack propagation was observed in the specimens after proportional and nonproportional LCF tests. PY - 1995 U6 - https://doi.org/10.1016/0921-5093(94)09690-2 SN - 0921-5093 SN - 1873-4936 VL - 196 IS - 1 SP - 19 EP - 24 PB - Elsevier CY - Amsterdam AN - OPUS4-2503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gemeinert, Marion A1 - Dörfel, Ilona A1 - Griepentrog, Michael A1 - Gross, U. A1 - Klaffke, Dieter A1 - Knabe, C. A1 - Kranz, I. A1 - Österle, Werner T1 - Biological response to micron- and nanometer-sized particles known as potential wear products from artificial hip joints: Part I: Selection and characterization of model particles KW - Hip joint endoprostheses KW - Wear products KW - Particle size distribution KW - Model particles KW - Dispersing behavior of particles PY - 2009 U6 - https://doi.org/10.1002/jbm.a.31952 SN - 1549-3296 SN - 1552-4965 VL - 89A IS - 2 SP - 379 EP - 389 PB - Wiley CY - Hoboken, NJ AN - OPUS4-19345 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -