TY - JOUR A1 - Dmitriev, A. I. A1 - Nikonov, A. Y. A1 - Österle, Werner T1 - Molecular dynamics modeling of the sliding performance of an amorphous silica nano-layer - The impact of chosen interatomic potentials N2 - The sliding behavior of an amorphous silica sample between two rigid surfaces is in the focus of the present paper. Molecular Dynamics using a classical Tersoff’s potential and a recently developed ReaxFF potential was applied for simulating sliding within a thin film corresponding to a tribofilm formed from silica nanoparticles. The simulations were performed at different temperatures corresponding to moderate and severe tribological stressing conditions. Simulations with both potentials revealed the need of considering different temperatures in order to obtain a sound interpretation of experimental findings. The results show the striking differences between the two potentials not only in terms of magnitude of the resistance stress (about one order of magnitude) but also in terms of friction mechanisms. The expected smooth sliding regime under high temperature conditions was predicted by both simulations, although with Tersoff’s potential smooth sliding was obtained only at the highest temperature. On the other hand, at room temperature Tersoff-style calculations demonstrate stick-slip behavior, which corresponds qualitatively with our experimental findings. Nevertheless, comparison with a macroscopic coefficient of friction is not possible because simulated resistance stresses do not depend on the applied normal pressure. KW - Molecular dynamics KW - Thin tribofilm KW - Resistance stress KW - Sliding simulation KW - Amorphous silica PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-449366 DO - https://doi.org/10.3390/lubricants6020043 SN - 2075-4442 VL - 6 IS - 2 SP - 43, 1 EP - 11 PB - MDPI CY - Basel AN - OPUS4-44936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Nikonov, A. Y. A1 - Dmitriev, A. I. ED - Krzanowski, J. T1 - MD sliding simulations of amorphous tribofilms consisting of either SiO2 or carbon N2 - The sliding behaviors of two simplified tribofilms with amorphous structure consisting either of SiO₂ molecules or C atoms were simulated by molecular dynamics modeling. The objective was to identify mechanisms explaining the experimentally observed lubricating properties of the two amorphous films. The impacts of layer thickness, normal pressure, temperature and different substrate materials were studied systematically, while the sliding velocity was kept constant at 30 m/s. While the layer thickness was not critical, all the other parameters showed special effects under certain conditions. Normal pressure impeded void formation and could even eliminate voids if applied at high temperature. Stick-slip sliding was changed to smooth sliding at high temperature due to void healing. Considering the carbon film, high friction forces and shearing of the entire film was observed with diamond substrates, whereas interface sliding at low friction forces and an amorphous layer of iron mixed with carbon was observed if the supporting substrates consisted of α-Fe. Both films show a decrease of friction forces and smooth sliding behavior at elevated temperature, corresponding well to the tribological behavior of and advanced nanocomposite sliding against a steel disc under severe stressing conditions when high flash temperatures can be expected. KW - dry friction KW - amorphous silica film KW - amorphous carbon film KW - sliding simulation KW - molecular dynamics PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-379367 DO - https://doi.org/10.3390/lubricants4030024 VL - 4 IS - 24 PB - MDPI CY - Basel, Switzerland AN - OPUS4-37936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dmitriev, A.I. A1 - Österle, Werner T1 - Sliding simulations with variable amounts of copper and graphite mixed with magnetite N2 - Copper is one of the most important components in brake pads and its amount can reach up to 14%. In spite of a number of positive features copper usage in brake pad formulations has recently become the subject of considerable discussions, primarily due to concerns about potential risks related to environmental impacts of copper particles. So, for developing new pad formulations with possible replacements of copper content, it is very important to understand the functionality of copper additions to brake friction materials. In the paper theoretical investigation of the role of copper as a pad ingredient was carried out on the basis of modelling by the method of movable cellular automata (MCA). Our previous studies show that copper as a constituent of the tribofilm formed during braking provides smooth sliding by forming a granular layer of mechanically mixed materials from the friction layers. In the present study the concentration of copper particles in a Fe3O4-matrix was varied systematically in the range 5.5-28 vol. % and compared to mixtures with the same amount of graphite nanoparticles. The sliding simulations were performed while assuming material properties at 500°C in order to assess the beneficial role of copper during severe braking conditions corresponding to fading cycles during dynamometer testing. T2 - EuroBrake 2016 CY - Milano, Italy DA - 13.06.2016 KW - Movable cellular automata KW - Copper KW - Sliding simulation KW - Third body KW - Tribofilm PY - 2016 UR - www.eurobrake.net VL - EB2016-SVM-054 SP - 1 EP - 7 PB - FISITA AN - OPUS4-37938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Orts-Gil, G. A1 - Österle, Werner ED - Tantra, R. T1 - Reference nanomaterials N2 - This chapter reviews relevant aspects of the still less explored field of RNMs. In the first part, definition of RMs according to different metrological levels was presented as well as the general strategy on their development. In the second part, the importance of RNMs in material science and nanotoxicology is explained and considerations on the use of silica nano-objects as potential future reference material was discussed. Overall, several points should be highlighted from this chapter: Definition of a reference material depends on the level of standardization. Certified reference material represents the highest level of traceability. Different types of reference materials, standard materials and certified reference materials are available, as shown in Table 3.1. The preparation of nano-objects with well-defined mechanical properties is still an unsolved issue and thus needs further R&D activities. Nevertheless, amorphous silica seems to be a promising candidate for reaching this objective. Traceable properties of nanomaterials are still limited to few cases such as primary particle size and thickness measurements of very thin films. In general, developed RMs are monoparametric thus, only one characteristic of the nano-objects is reported. In nanotoxicology, the challenge is in the development of suitable RNM that bears similarities to the measurements made on the sample analysed. KW - Reference material KW - Certified reference material KW - Nanostructure PY - 2016 SN - 9781118753590 SP - 49 EP - 61 PB - Wiley & Sons, Ltd. ET - 1 AN - OPUS4-37943 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolter, Christian A1 - Österle, Werner A1 - Gradt, Thomas T1 - Metal sulphides as friction stabilisers under variable humidity N2 - Neben Kohlenstoff werden Metallsulfide in jeder Standardrezeptur für Bremsbeläge als Reibungsstabilisatoren verwendet. Um deren Wirkung zu untersuchen, wurden verschiedene Pulvermischungen in einer Stift-Scheibe-Anordnung tribologisch beansprucht, um künstliche dritte Körper zu erzeugen und zu testen, deren definierte Zusammensetzungen aus drei wichtigen Bestandteilen einer realen Reibschicht bestehen: Magnetit, Graphit und div. Metallsulfide. N2 - Besides carbon, metal sulphides are used in every standard brake pad formulation as friction stabilisers. In order to investigate their impact, various powder mixtures were tribologically stressed in a pin-on-disc device in order to produce and test artificial third bodies. containing the three main components of a real friction film, namely magnetite, graphite and a metal sulphide of interest. Since the sliding behaviour is influenced by the relative humidity the powder mixtures are tested at low, medium and high moisture levels. The tests revealed that the presence of graphite dominates the friction behaviour as well as the humidity sensitivity. The powders were prepared by either manual mixing or high energy ball-milling. Interestingly, all ball-milled blends provided coefficients of friction within the desired range for braking, which was attributed to the effect of zirconia particles from wear debris of the milling balls. The zirconia particles prevent the formation of solid lubricant films on the surfaces and support a homogeneous mixture of all constituents of the powder. Optimum brake performance is gained by an optimum combination of solid lubricants and abrasives. T2 - 57. Tribologie-Fachtagung CY - Göttingen, Germany DA - 26.09.2016 KW - Friction KW - Metal sulphides KW - Brake pad formulation PY - 2016 SN - 978-3-9817451-1-5 SP - 1.5/1 EP - 1.5/6 AN - OPUS4-37838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dmitriev, A. I. A1 - Österle, Werner ED - Österle, Werner ED - Zhang, G. T1 - The role of solid lubricants for brake friction materials N2 - This review article comprises of three parts. Firstly, reports of brake manufacturers on the beneficial impact of solid lubricants for pad formulations are surveyed. Secondly, since tribofilms were identified to play a crucial role in friction stabilization and wear reduction, the knowledge about tribofilm structures formed during automotive braking was reviewed comprehensively. Finally, a model for simulating the sliding behavior of tribofilms is suggested and a review on modelling efforts with different model structures related to real tribofilms will be presented. Although the variety of friction composites involved in commercial brake systems is very broad, striking similarities were observed in respect to tribofilm nanostructures. Thus a generalization of the tribofilm nanostructure is suggested and prerequisites for smooth sliding performance and minimal wear rates have been identified. A minimum of 13 vol.% of soft inclusions embedded in an iron oxide based tribofilm is crucial for obtaining the desired properties. As long as the solid lubricants or their reaction products are softer than magnetite, the main constituent of the tribofilm, the model predicts smooth sliding and a minimum of wear. KW - Solid lubricant KW - Friction KW - Automotive braking KW - Tribofilm KW - Sliding simulation KW - MCA-modeling PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-355973 UR - www.mdpi.com/journal/lubricants DO - https://doi.org/10.3390/lubricants4010005 SN - 2075-4442 VL - 4 IS - 1 SP - 5 EP - 26 PB - MDPI CY - Basel, Switzerland AN - OPUS4-35597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Dmitriev, Andrey T1 - Some considerations on the role of third bodies during automotive braking N2 - Third bodies, also termed friction layers, tribofilms or secondary contact patches, are layers of more or less compacted wear debris between pads and rotor of a disc brake. Our approach of assessing the sliding behavior and friction properties induced by third bodies has been: i) structural characterization after AK-master test procedure, ii) sliding simulation of model structures similar to the observed ones but with simpler and well defined compositions, and iii) verification of simulation results by pin-on-disc tests with artificial third bodies showing the same microstructures and compositions as the model structures. The idea was to simulate structure formation during real braking conditions by high energy ball milling of appropriate powder blends. The final outcome of numerous parameter studies was that a third body containing 15 vol% soft ingredients and 0-20 vol % hard ingredients, both distributed homogeneously in a nanocrystalline iron oxide matrix, should be most desirable for braking. This general description of the optimum third body structure and several parameter studies performed by modelling enabled us to interpret a number of features of the AK-master test procedure, such as i) friction evolution during bedding, ii) the role of solid lubricants in respect to the initiation of smooth sliding behavior, and iii) friction evolution during a single braking event (in-stop behavior). KW - Tribofilm KW - Thrid body KW - Friction material KW - MCA-modelling KW - Automotive braking PY - 2014 DO - https://doi.org/10.4271/2014-01-2490 SN - 1946-3995 SN - 1946-4002 VL - 7 IS - 4 SP - 1287 EP - 1294 PB - SAE International CY - Warrendale, Pa. AN - OPUS4-31930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Deutsch, Cornelius A1 - Dörfel, Ilona A1 - Gradt, Thomas A1 - Häusler, Ines A1 - Orts-Gil, G. A1 - Prietzel, C. A1 - Schneider, Thomas T1 - Final outcome of a fundamental research project on tribofilms formed during automotive braking, Part 1: Experimental studies N2 - In order to obtain a better understanding of the role of tribofilms during automotive braking, their structures were investigated and the essential features identified. Next, different ingredient combinations were studied by preparing some model materials with simpler compositions than real tribofilms. A test method was developed for verifying the tribological properties of the model materials and for comparison with results obtained with numerical sliding simulations of such structures. Prerequisites of good brake Performance properties were identified. Although the coefficient of friction could be varied in a wide ränge, smooth sliding conditions could only be achieved with values smaller than 0.4. Tests with artificial third body powders turned out to be useful as screening method for the selection of raw materials for brake pad formulations. T2 - EuroBrake 2014 CY - Lille, France DA - 13.05.2014 KW - Tribofilm KW - Third body KW - Pad ingredients KW - Ball milling KW - Pin-on-disc test PY - 2014 SN - 978-0-9572076-4-6 SP - 1 EP - 8 PB - FISITA CY - London AN - OPUS4-35039 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dmitriev, A.I. A1 - Kloß, Heinz A1 - Österle, Werner T1 - Final outcome of a fundamental research project on tribofilms formed during automotive braking, Part 2: Numerical simulation N2 - In part 1 it was shown that tribofilms usually are 100 nm thick and exhibit a multiphase nanocrystalline structure. The objective of our modelling efforts was to obtain a better understanding of the sliding behaviour and associated friction properties and to study the impact of internal and external parameters on these properties. The method of movable cellular automata (MCA) was used. The third bodies were considered as aggregates of linked nanoparticles which may decompose and form a layer of granulär material, the so-called mechanically mixed layer (MML), if certain fracture criteria are fulfilled. The basic model structure which consists of Fe3Ü4 nanoparticles with 13 % graphite inclusions was used. In order to assess the robustness of the model the following parameter studies were performed. The pressure ränge at an asperity contact was varied between 15 and 50 MPa. The mechanical properties of the oxide were varied between brittle and ductile behaviour corresponding to room temperature and high temperature behaviour. The mechanical properties of the soft ingredient were varied + 50 % of the properties of graphite. The influence T2 - EuroBrake 2014 CY - Lille, France DA - 13.05.2014 KW - Tribofilm KW - Third body KW - Dry friction KW - Modelling KW - Movable cellular automata PY - 2014 SN - 978-0-9572076-4-6 SP - 1 EP - 9 PB - FISITA CY - London AN - OPUS4-35040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dmitriev, A. I. A1 - Österle, Werner T1 - Modelling the sliding behaviour of tribofilms forming during automotive braking: impact of loading parameters and property range of constituents N2 - The impact of pressure, sliding velocity and property variation of constituents on the sliding behaviour of a model tribofilm was studied with the method of movable cellular automata (MCA). Whereas a clear pressure dependency of the coefficient of friction (COF) was always observed and could be correlated with the structure formation in terms of varying thickness of a mechanically mixed layer, the impact of the other parameters was either negligible or rather weak. Only if a brittle-to-ductile Transition of the oxide-based tribofilm was assumed, a significant decrease in the COF level was predicted. Temperature-dependent property changes can be neglected during MCA modelling, unless this transition takes place. For magnetite-based tribofilms, the transition temperature is beyond 800 °C, i.e. a temperature leading to fading effects during braking anyway. Thus, it could be concluded that, except for very severe braking conditions, sliding simulations with the MCA method yield meaningful results without considering temperature-dependent mechanical properties. KW - Tribofilm KW - Sliding behaviour KW - Friction KW - Movable cellular automata KW - Mechanically mixed layer PY - 2014 DO - https://doi.org/10.1007/s11249-013-0274-z SN - 1023-8883 SN - 1573-2711 VL - 53 IS - 1 SP - 337 EP - 351 PB - Springer AN - OPUS4-38548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kloß, Heinz A1 - Österle, Werner A1 - Dmitriev, A.I. ED - Bartz, Wilfried J. T1 - Modelling mechanical friction and wear behaviour using numerical results of the movable cellular automata (MCA) method N2 - In the mechanical friction and wear process, normal and tangential (shear) forces cause elastic and plastic deformations, generate cracks and form loose wear particles through fracture processes. Depending on the working conditions, the material properties and the real contact Situation (topography), a third body is formed as a mechanical ly mixed layer, which determines different running-in and steady-state behaviours. Two dimensional (2D) MCA Simulation results will be described via empirical equations, which are related to the incubation time (period without wear) and the following running-in wear rate (kinetic concept of strength, fatigue wear model). In order to understand the running-in and steady-state wear, kinetic model equations for mass balance of the third body are useful and are therefore to be included in the investigation. For a more complex material behaviour, numerical Simulation results are also presented for friction at the pad-disk interface of automotive brakes. T2 - 19th International colloquium Tribology - Industrial and automotive lubrication CY - Stuttgart/Ostfildern, Germany DA - 21.01.2014 PY - 2014 SN - 978-3-943563-10-8 SP - Paper 8.10, 1 EP - 7 CY - Stuttgart/Ostfildern AN - OPUS4-30437 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Österle, Werner ED - Czichos, Horst T1 - Sub-surface microstructural analysis N2 - Many performance properties of devices or interacting machine parts are related to superficial layers which often show completely different or at least modified microstructures compared to the bulk materials. A quasi non-destructive technique will be described which enables us to obtain detailed information of a material's state at a certain site of interest down to a depth of 10 µm from the surface with nanometre or even atomistic resolution. KW - FIB-Technik KW - Zielpräparation KW - Randschichtanalyse KW - Nanocharakterisierung PY - 2013 SN - 978-3-642-25849-7 SN - 978-3-642-25850-3 DO - https://doi.org/10.1007/978-3-642-25850-3_16 IS - Chapter 16 SP - 323 EP - 337 PB - Springer CY - Berlin Heidelberg AN - OPUS4-27644 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Natte, Kishore A1 - Friedrich, Jörg Florian A1 - Wohlrab, Sebastian A1 - Lutzki, J. A1 - von Klitzing, R. A1 - Österle, Werner A1 - Orts-Gil, Guillermo T1 - Impact of polymer shell on the formation and time evolution of nanoparticle-protein corona N2 - The study of protein corona formation on nanoparticles (NPs) represents an actual main issue in colloidal, biomedical and toxicological sciences. However, little is known about the influence of polymer shells on the formation and time evolution of protein corona onto functionalized NPs. Therefore, silicapoly(ethylene glycol) core–shell nanohybrids (SNPs@PEG) with different polymer molecular weights (MW) were synthesized and exhaustively characterized. Bovine serum albumin (BSA) at different concentrations (0.1–6 wt%) was used as model protein to study protein corona formation and time evolution. For pristine SNPs and SNPs@PEG (MW = 350 g/mol), zeta potential at different incubation times show a dynamical evolution of the nanoparticle–protein corona. Oppositely, for SNPs@PEG with MW ≥2000 g/mol a significant suppression of corona formation and time evolution was observed. Furthermore, AFM investigations suggest a different orientation (side-chain or perpendicular) and Penetration depth of BSA toward PEGylated surfaces depending on the polymer length which may explain differences in protein corona evolution. KW - Nanoparticles KW - Silica KW - PEGylation KW - Protein corona KW - BSA KW - Biointerface PY - 2013 DO - https://doi.org/10.1016/j.colsurfb.2012.11.019 SN - 0927-7765 VL - 104 SP - 213 EP - 220 PB - Elsevier AN - OPUS4-38547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Deutsch, Cornelius A1 - Rooch, Heidemarie A1 - Dörfel, Ilona T1 - Friction films on C-SiC discs after dynamometer tests with different commercial brake pads T2 - EuroBrake 2012 CY - Dresden, Germany DA - 2012-04-16 KW - Ceramic disc KW - Friction film KW - PMC-pad KW - SM-pad KW - Third body PY - 2012 IS - EB2012-FM-01 SP - 1 EP - 9 AN - OPUS4-26823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dmitriev, A. I. A1 - Österle, Werner A1 - Kloß, Heinz A1 - Orts-Gil, Guillermo T1 - A study of third body behaviour under dry sliding conditions. Comparison of nanoscale modelling with experiment N2 - Automotive brake pads consist of many components but it is still not entirely clear which role each of the elements of this complex composition plays to provide the specified regimes of sliding. This is due to the mutual interaction of multiscale mechanisms, realized during the friction. In this work we have attempted to partly answer this question using computer simulations. Since the simulation allows us to consider various combinations of the structure of the system being simulated ceteris paribus, it becomes possible to understand the role of each constituent sequentially. The main attention is paid to the structure and composition of the thin film that forms on the surface of both bodies as a result of compaction of the wear product, its chemical composition and oxidation. This layer, also named a third body or friction film, differs in composition and microstructure from the two first bodies. We considered a single contact for the steady state sliding when the structure and composition of friction films already are formed. As a modelling tool we used the method of movable cellular automata, which has well proven itself in solving of such tasks. We investigated the influence of modification of the structure and composition of the third body on the features of system behaviour at friction. To assess the adequacy of the numerical model, experimental studies with an artificial third body were also carried out. The Simulation results are in good agreement with experimental data. KW - Third body KW - Dry sliding KW - Mechanically mixed layer KW - Computer simulation PY - 2012 DO - https://doi.org/10.3176/eng.2012.3.12 SN - 1736-6038 SN - 1736-7522 VL - 18 IS - 3 SP - 270 EP - 278 AN - OPUS4-38545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Natte, Kishore A1 - Österle, Werner A1 - Friedrich, Jörg Florian A1 - von Klitzing, R. A1 - Orts-Gil, Guillermo T1 - Tuning interfacial properties and colloidal behavior of hybrid nanoparticles by controlling the polymer precursor N2 - A facile and versatile synthetic route for controlling the size and surface potential of organic–inorganic hybrid silica nanoparticles (NPs) is introduced in this paper. For polymer-grafted NPs, the density of polymer chains on the surface is strongly affected by the concentration of precursor. Nevertheless, for condensed NPs, the precursor concentration determines the particle size but not the density of polymer chains on the surface or the adsorption of bovine serum albumin (BSA). Results presented here may have Major implications in biomedical and colloidal chemistry since interfacial and colloidal properties are known to drive several processes associated with nanoparticles in biological media. KW - BSA KW - Bio-interface KW - Nanosilica hybrids KW - PEG KW - Protein corona PY - 2012 DO - https://doi.org/10.1002/macp.201200148 SN - 0025-116X SN - 1022-1352 SN - 1521-3935 VL - 213 IS - 22 SP - 2412 EP - 2419 PB - Whiley-VCH CY - Weinheim AN - OPUS4-38549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Bresch, Harald A1 - Dörfel, Ilona A1 - Steinborn, Gabriele A1 - Krietsch, Arne A1 - Langner, Jeanette A1 - Schmidt, Martin A1 - Österle, Werner A1 - Seeger, Stefan T1 - Physical-chemical characterization of NM105(P25) N2 - NM 105, Ti02 (P25) could not be ignited as dust layer and dispersed in air as dust/air-mixture as well. This dust is not dust explosible and the burning behaviour corresponds to Burning Class 1 (no Ignition). The results have shown that the tested sample is thus not combustible at all, because it is already oxidized completely. KW - OECD KW - WPMN KW - TiO2 KW - NM105 KW - P25 KW - Sponsorship programme PY - 2012 SP - 1 EP - 18 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-27322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cristol, A.L. A1 - Desplanques, Y. A1 - Österle, Werner A1 - Degallaix, G. T1 - Coupling between thermal localisation and friction mechanisms: heat accumulation effect N2 - Heat accumulation induced by a succession of railway brakings leads to changes of the friction conditions occurring in pad-disc contact. Infrared thermography observations show a progressive increase of surface temperature over the succession, as well as a modification of the hot band migration phenomenon. From a tribological point of view, the heat accumulation, accompanied by a wear increase, progressively modifies the friction behaviour from one braking to the next. Post-mortem observations of pads are performed on surface by scanning electron microscopy and in depth after Focus Ion Beam cut by scanning ion microscopy. Observations show that, with heat accumulation, the third body quantity rises inside the contact, in accordance with wear increase. It is concluded that source flows of third body, which increase with temperature, feed aplenty the contact and modify its load-bearing capacity. T2 - JEF 2010 - 6th European conference on braking CY - Lille, France DA - 2010-11-24 KW - Successive braking KW - Heat accumulation KW - Thermal localisation KW - Wear KW - SEM KW - FIB PY - 2010 SP - 61 EP - 69 AN - OPUS4-22729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Bresch, Harald A1 - Dörfel, Ilona A1 - Fink, C. A1 - Giese, A. A1 - Prietzel, Claudia A1 - Seeger, Stefan A1 - Walter, J. T1 - Examination of airborne brake dust T2 - JEF 2010 - 6th European conference on braking CY - Lille, France DA - 2010-11-24 KW - Brake dust KW - Nanoparticles KW - Size-distribution PY - 2010 SP - 1 EP - 6(?) AN - OPUS4-22655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dmitriev, A.I. A1 - Österle, Werner A1 - Kloß, Heinz T1 - Nano-scale modeling of pad-disc interface. The influence of copper as a pad ingredient. T2 - JEF 2010 - 6th European conference on braking CY - Lille, France DA - 2010-11-24 KW - Friction layer KW - Copper particles KW - MCA-modelling PY - 2010 SP - 1 EP - 6(?) AN - OPUS4-22656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Österle, Werner A1 - Kloß, Heinz A1 - Dmitriev, A.I. ED - Bartz, Wilfried J. ED - Friedrich Franek, T1 - Friction control during automotive braking - experimental observations and simulation at the nanometer scale T2 - 3rd Vienna International Conference - Nano-Technology CY - Vienna, Austria DA - 2009-03-18 KW - Bremse KW - Dritter Körper KW - Verschleiß KW - Reibung KW - Nanocharakterisierung KW - Modellierung PY - 2009 SN - 978-3-901657-32-0 SP - 335 EP - 341 AN - OPUS4-19222 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Dmitriev, A.I. A1 - Österle, Werner T1 - Numerical modeling of dry friction sliding in pad-disc interface at the nanoscale T2 - 37th Summer school-conference - Advanced problems in mechanics (APM 2009) CY - St. Petersburg, Russia DA - 2009-06-30 PY - 2009 SN - 978-5-91339-029-5 SP - 174 EP - 182 AN - OPUS4-19750 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kranzmann, Axel A1 - Hünert, Daniela A1 - Rooch, Heidemarie A1 - Urban, Ingrid A1 - Schulz, Wencke A1 - Österle, Werner T1 - Reactions at the interface between steel and oxide scale in wet CO2 containing atmospheres N2 - The resistance of structural steels against corrosion in CO2-H2O and CO2-H2O-O2 atmospheres at temperatures above 550°C was observed with high magnification methods. The test atmosphere is the basic composition of an oxyfuel coal combustion atmosphere. The analytical information base was applied to develop reaction schemes for the oxidation of steels. It was demonstrated that the formation of phases and the kinetics of oxidation reactions in this atmospheres is affected by the formation of intermediate iron hydroxide and a high carbon activity. In the temperature regime above 550°C the thermal equilibrium between H2O, CO2 and Fe reacted and formed CO. CO triggers the formation of FeO and carbides and increases the reaction kinetics. Porosity at the interface is established by gaseous phases such as Fe(OH)2 or H2O. H2 formation is not limited to the steel - oxide interface but can occur in the whole oxide scale. Examples of the experimental results were compared with a thermodynamic approach. The objective of the work was to derive qualitative rules of the basic corrosion reactions. T2 - NACE International corrosion conference 2009 CY - Atlanta, Georgia, USA DA - 2009-03-22 KW - High temperature corrosion KW - Corrosion gases KW - Mild steels KW - 9-12% Cr-steels KW - Hydrogen transport KW - Oxyfuel combustion PY - 2009 SP - 1 EP - 10 (Paper 09265) AN - OPUS4-22334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Kloß, Heinz A1 - Dmitriev, A.I. T1 - Friction control during automotive braking: experimental observations and simulation at nanometer scale KW - Friction control KW - Friction film KW - Automotive braking KW - MCA model KW - Nanostructure PY - 2009 DO - https://doi.org/10.1179/175158309X12586382418454 SN - 1751-5831 VL - 3 IS - 4 SP - 196 EP - 202 PB - Maney CY - London AN - OPUS4-20829 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Österle, Werner A1 - Bresch, Harald A1 - Dörfel, Ilona A1 - Prietzel, Claudia A1 - Seeger, Stefan A1 - Fink, C. A1 - Giese, A. A1 - Walter, J. T1 - Surface film formation and dust generation during brake performance tests T2 - Braking 2009 CY - York, UK DA - 2009-06-09 KW - Bremse KW - Dritter Körper KW - Verschleiß KW - Reibung KW - Nanocharakterisierung KW - Aerosol PY - 2009 SN - 978-1-84334-559-6 IS - C672/028/09 SP - 29 EP - 38 PB - Woodhead Publishing Ltd AN - OPUS4-19574 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Österle, Werner A1 - Kloß, Heinz A1 - Dmitriev, A.I. T1 - Modeling of Friction Evolution and Assessment of Impacts on Vibration Excitation at the Pad-Disc Interface T2 - 26th Annual Brake Colloquium & Exhibition CY - San Antonio, Texas, USA DA - 2008-10-12 KW - Friction materials KW - MCA-modeling KW - Friction films KW - Noise propensity KW - Friction-induced vibrations PY - 2008 SN - 978-0-7680-2097-7 IS - 2008-01-2582 SP - 303 EP - 311 AN - OPUS4-18695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dmitriev, A.I. A1 - Smolin, A.Y. A1 - Psakhie, S.G. A1 - Österle, Werner A1 - Kloß, Heinz A1 - Popov, V.L. T1 - Computer modeling of local tribological contacts by the example of the automotive brake friction pair N2 - In the paper the method of discrete modeling (movable cellular automata method) and combined discrete-continuous description of the simulated medium are used to analyze processes occurring in the local contact of the automotive brake system. The characteristic size of the considered region is 1.5 ?m. The following contact situation is simulated: steel fiber coated by an iron oxide film as the brake pad and pearlitic steel also coated by an iron oxide layer as the disc. On the assumption of oxide layer wearing we simulate the iron oxide - iron oxide, iron oxide - metal and metal - metal contacts. The calculation results for the friction coefficient for various contact situations give quite adequate values. For example, for the oxide - oxide system the calculated coefficient is approximately equal to 0.4, while for the metal - metal contact the obtained value varies from 0.7 to 0.9. Analysis of a set of the obtained results allows concluding that oxide is formed more rapidly than the sliding layer, which in turn makes the friction coefficient value stabilized. PY - 2008 DO - https://doi.org/10.1016/j.physme.2008.03.008 SN - 1029-9599 VL - 11 IS - 1-2 SP - 73 EP - 84 PB - Inst. of Strength Physics and Materials Science SB RAS CY - Tomsk AN - OPUS4-18698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Dmitriev, A.I. A1 - Kloß, Heinz ED - Jayashree Bijwe, T1 - Basic considerations for the development of friction materials T2 - IWAAFC-2, International Workshop on Advances in Asbestos-free Friction Composites CY - Delhi, India DA - 2008-02-07 PY - 2008 SP - 24 EP - 51 PB - Indian Academy of Sciences CY - Delhi, India AN - OPUS4-18701 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Müller, Urs A1 - Meng, Birgit A1 - Österle, Werner A1 - Gardei, André ED - Stark, J. T1 - Characterization of granulated blast furnace slag by means of the combined application of the FIB/TEM technique T2 - 16. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 2006-09-20 PY - 2006 SN - 3-00-018263-2 VL - 1 SP - 1-0189 - 1-0195 PB - Bauhaus-Univ. CY - Weimar AN - OPUS4-13717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Müller, Urs A1 - Desplanques, Y. A1 - Bulthé, A.-L. A1 - Degallaix, G. A1 - Dmitriev, A.I. T1 - 3rd Body formation of two different brake pad materials designed for railway application T2 - 5th European Conference on Braking (JEF 2006) CY - Lille, France DA - 2006-11-08 PY - 2006 SP - 107 EP - 115 AN - OPUS4-18699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Dmitriev, A.I. A1 - Urban, Ingrid ED - Jayashree Bijwe, T1 - Characterization of up to date brake friction materials T2 - IWAAFC-1, International Workshop on Advances in Asbestos free Friction Composites CY - Delhi, India DA - 2006-01-05 PY - 2006 SP - 21 EP - 35 CY - Delhi, India AN - OPUS4-18700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Österle, Werner A1 - Urban, Ingrid A1 - Gesatzke, Wolfgang A1 - Rooch, Heidemarie ED - Bartz, Wilfried J. T1 - Characterization and evaluation of the formation of friction layers during braking with conventional PMC friction material against a cast iron rotor T2 - 14th International Colloquium Tribology, "Tribology and Lubrication Engineering" CY - Stuttgart, Germany DA - 2004-01-13 PY - 2004 SN - 3-924813-54-X VL - 1 SP - 483 EP - 489 PB - Techn. Akad. Esslingen CY - Ostfildern AN - OPUS4-3494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Senoner, Mathias A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Österle, Werner A1 - Kaiander, I. A1 - Sellin, R. L. A1 - Bimberg, D. ED - Wilkening, G. ED - Koenders, L. T1 - Testing the Lateral Resolution in the Nanometre Range with a New Type of Certified Reference Material T2 - NanoScale 2004 Seminar ; 6th Seminar on Quantitative Microscopy ; 2nd Seminar on Nanoscale Calibration Standards and Methods CY - Braunschweig, Germany DA - 2004-03-25 KW - Laterale Auflösung KW - Nanometrologie KW - Nanotechnologie KW - Oberflächenanalytik KW - Zertifiziertes Referenzmaterial PY - 2004 SN - 3-527-40502-X DO - https://doi.org/10.1002/3527606661.ch21 SP - 282 EP - 294 PB - Wiley-VCH CY - Weinheim AN - OPUS4-7541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Seah, M.P. A1 - Spencer, S.J. A1 - Bensebaa, F. A1 - Vickridge, I. A1 - Danzebrink, H. A1 - Krumrey, M. A1 - Gross, Thomas A1 - Österle, Werner A1 - Wendler, E. A1 - Rheinländer, B. A1 - Azuma, Y. A1 - Kojima, I. A1 - Suzuki, N. A1 - Suzuki, M. A1 - Tanuma, S. A1 - Moon, D.W. A1 - Lee, H.J. A1 - Cho, H.M. A1 - Chen, H.Y. A1 - Wee, A. T. S. A1 - Osipowicz, T. A1 - Pan, J.S. A1 - Jordaan, W.A. A1 - Hauert, R. A1 - Klotz, U. A1 - van der Marel, C. A1 - Verheijen, M. A1 - Tamminga, Y. A1 - Jeynes, C. A1 - Bailey, P. A1 - Biswas, S. A1 - Falke, U. A1 - Nguyen, N.V. A1 - Chandler-Horowitz, D. A1 - Ehrstein, J.R. A1 - Muller, D. A1 - Dura, J.A. T1 - Ultra-thin SiO2 on Si, Part V: Results of a CCQM Pilot Study of Thickness Measurements KW - SiO2 KW - Thin films KW - Thickness KW - XPS KW - Ellipsometry KW - TEM PY - 2003 SN - 1473-2734 SP - 57 pages AN - OPUS4-4118 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner T1 - Controlling the microstructure of engineering materials - a measure for obtaining taylored properties T2 - Iren University of Science and Technology CY - Tehran, Iran DA - 2002-05-21 PY - 2002 AN - OPUS4-6106 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner T1 - The focused ion beam technique - eine interessante Alternative, auch für konventionelle Werkstoffe T2 - VDEh-Arbeitskreis, Elektronenmicroskopie CY - Duisburg, Germany DA - 2002-11-07 PY - 2002 AN - OPUS4-6108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nebauer, E. A1 - Österle, Werner A1 - Hilsenbeck, J. A1 - Würfl, J. A1 - Klein, A. T1 - XTEM and TFXRD investigations of ohmic Ti/Al/Ti/Au/WSiN contacts on AlGaN/GaN HFET layer systems N2 - The microstructural features of the high-temperature-stable ohmic contact system Ti/Al/Ti/Au/WSiN on AlGaN/GaN were investigated using analytical transmission electron microscopy and thin film x-ray diffraction. For two typical rapid thermal annealing steps at 750 ◦C (non-ohmic behaviour) and 850 ◦C (ohmic behaviour) the intermetallic phases at the metal–semiconductor interface are presented. Increased annealing leads to the transformation of an Al2Au-AlAuTi phase mixture to a mixture of Al2Au-Al3Au8 phases and the formation of Ti-Al-nitride layers at the interfaces. In light of these results the electrical contact properties are discussed. KW - Ohmic contact KW - WSiN diffusion barrier KW - Rapid thermal annealing KW - Intermetallic phases KW - AlGaN/GaN heterostructure PY - 2002 SN - 0268-1242 VL - 17 SP - 249 EP - 254 PB - IOP Publishing Ltd AN - OPUS4-38543 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Würfl, J. A1 - Hilsenbeck, J. A1 - Nebauer, E. A1 - Tränkle, G. A1 - Obloh, H. A1 - Österle, Werner T1 - Reliability of AIGaN/GaN HFETs comprising refractory ohmic and Schottky contacts N2 - Recent progress in the development of A1GaN/GaN heterostructure field effect transistors (HFETs) Shows the great potential towards high temperature / high power electronics. Nevertheless investigations on reliability properties of GaN-based devices are still at the beginning. The frequently used Ti/A1 based ohmic and Pt based Schottky contacts suffer from strong Degradation after aging at elevated temperatures. Therefore new contact systems have to be employed. Concerning the source and drain metallization we used an amorphous WSiN barrier layer as applied for GaAs on top of the Ti/Al-based ohmic contact. This technique significantly reduces the in-diffusion of the Au-containing overlayer, furthermore the barrier layer guaranties smooth contact morphology after RTA and aging, respectively. For the Schottky metallization the Ir/Au system was used. Reliability studies performed on HFET devices containing refractory Ti/A1/Ti/Au/WSiN ohmic and Ir/Au Schottky contacts demonstrate stable conditions during 120h aging at 500°C. KW - Semiconductor KW - Reliability KW - Contact resistance KW - Heterostructure field effect transistor PY - 2000 SN - 0026-2714 VL - 40 SP - 1689 EP - 1693 PB - Elsevier AN - OPUS4-38541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bettge, Dirk A1 - Österle, Werner T1 - “Cube slip” in near-[111] oriented specimens of a single-crystal nickel-base superalloy N2 - In the past few years, it has been discussed with increasing frequency, whether cube slip does occur in gamma' hardened nickel-base superalloys. Occurrence of cube slip has consequences for the modeling of orientation dependence of the CRSS. Until now, there are only few experimental investigations. In principle, cube slip should be possible in primitive cubic lattices (e.g. L12 ordered gamma' phase) but not in face centered cubic ones (e.g. Ni solid solution). The most favourable specimen orientations are near [111], where the Schmid factors for this type of glide exceed those for octahedral systems. There are two basic methods to detect cube slip: macroscopic slip trace analysis and Transmission electron microscopy (TEM) investigation of the dislocation structure. Few observations of cube slip by macroscopic slip traces are reported in the literature. But it is still uncertain under which test conditions cube slip occurs and what the dislocation mechanisms are. Cube slip was observed during tensile or compression tests of several first generation superalloys, but it seems not to occur during shear creep deformation (e.g. CMSX-4 at 980°C), and it is also lacking under conventional tensile or compression loading, if the gmma' particles are small. No observations were ever reported of dislocations gliding on {001} planes in matrix channels. KW - Cube slip KW - Nickel-base superalloy KW - Dislocations KW - TEM PY - 1999 DO - https://doi.org/10.1016/S1359-6462(98)00446-1 SN - 1359-6462 VL - 40 IS - 4 SP - 389 EP - 395 PB - Elsevier AN - OPUS4-38220 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reier, T. A1 - Schultze, J. W. A1 - Österle, Werner A1 - Buchal, C. T1 - Nucleation and growth of AlN nanocrystallites prepared by N+2 implantation N2 - The formation of AlN films prepared by N+2 ion implantation into aluminium was investigated using X-ray and Auger photoelectron spectroscopy ( XPS, AES) as well as cross-sectional transmission electron microscopy (XTEM). After 100-keV N+2 implantation of low doses (1×1017 cm−2), the formation of hexagonal AlN nanocrystals (crystal size <5 nm, Ncrystal=1017 cm−3) was observed. Their orientation is strongly correlated with the aluminium matrix. With the dose increasing to 3×1017 cm−2, crystal growth follows, finally forming a homogeneous AlN-layer. Furthermore, the diffraction patterns show an increasing amount of misorientation with increasing dose. From the crystal size distribution, we conclude that continuous nucleation takes place. Samples implanted with an energy of 3 keV exhibit analogous behaviour. Nitride growth was further investigated using microstructured AlN formed by 3-keV implantation through movable TEM-masks (structure size: 15–150 mm). In the case of high N+2 doses (D&5×1017 cm−2), AlN is detected by AES in the shielded area at a distance of up to 10 mm from the exposed region. The Diffusion coefficient was calculated to be 10−10 cm2 s−1. The formation of AlN proceeds in two steps. After a continuous nucleation, diffusion-assisted Crystal growth takes place until a homogeneous AlN layer results. KW - Aluminium nitride KW - Ion implantation KW - Nanocrystallites KW - Surface analysis KW - XTEM PY - 1998 SN - 0257-8972 VL - 103-104 SP - 415 EP - 420 PB - Elsevier AN - OPUS4-38539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuhmann, J. F. A1 - Chiang, C. H. A1 - Harde, P. A1 - Reier, F. A1 - Österle, Werner A1 - Urban, Ingrid A1 - Klein, A. T1 - Pt thin-film metallization for FC-bonding using SnPb60/40 solder bump metallurgy N2 - Platinum does not form any adherent oxides and can be easily wetted by tin-based solders. Platinum is also an available metallization in semiconductor laboratories. Therefore we investigated the diffusion of platinum thin-film metallizations into eutectic tin–lead solder by using a high-resolution secondary ion mass spectroscopy (SIMS) profiling from the back side. It is shown that an intermetallic phase (PtSn4) is formed during soldering, which controls the consumption of platinum during soldering and in operation. The consumption of platinum follows the well-known parabolic diffusion law. The activation energy of this process is 0.63 eV. Even at extended heating cycles of 2 min at 250°C, 190 nm from the original 300 nm of the platinum film remain undissolved. This high stability makes platinum a very attractive thin-film metallization for flip-chip (FC) bonding of new microsystems. KW - Pt thin film metallization KW - FC solder bonding KW - Diffusion KW - SIMS PY - 1998 SN - 0921-5093 VL - A242 SP - 22 EP - 25 PB - Elsevier AN - OPUS4-38540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sievert, Rainer A1 - Österle, Werner A1 - Olschewski, Jürgen A1 - Ziebs, Josef T1 - Physical interpretation of a viscoplastic model applied to high temperature performance of a nickel-base superalloy PY - 1997 SN - 0179-4841 SN - 0044-3093 VL - 88 SP - 416 EP - 424 PB - Hanser CY - München AN - OPUS4-2547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bettge, Dirk A1 - Jiao, F. A1 - Österle, Werner A1 - Ziebs, Josef ED - Lütjering, G. T1 - An extended model of the tension-compression asymmetry of single crystal nickel-base superalloys T2 - 6th International Fatigue Congress CY - Berlin, Germany DA - 1996-05-06 PY - 1996 SN - 0-08-042268-3 VL - 2 IS - 2 SP - 885 EP - 889 PB - Pergamon CY - Oxford AN - OPUS4-2508 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Fedelich, Bernard A1 - Frenz, Holger A1 - Österle, Werner A1 - Ohm, Katrin ED - Petit, J. T1 - Experimental and numerical evaluation of fatigue crack initiation and propagation for IN738LC at 850°C N2 - Interrupted LCF-tests at 850 deg C for Inconel 738LC have been carried out and the specimens have been intensively examined by REM to quantify the evolution of fatigue damage. Surface crack nucleation at oxidatized grain boundaries and coalescence of neighboring flaws occurred during the whole experiment. An anomalous fast single crack growth is observed just after nucleation, followed by a relative stagnation of the propagation in absence of coalescence. A statistical model is proposed that describes these pheonmena. It leads to an integro-differential equation for the crack density f(c,n) after n cycles, similar to the Bolzmann equation which describes the collision of molecules in a dilute gas. T2 - 11th Biennial European Conference on Fracture (ECF) CY - Poitiers-Futuroscope, France DA - 1996-09-03 PY - 1996 SN - 0-947817-92-1 VL - 2 SP - 1237 EP - 1242 PB - EMAS CY - Warley, West Midlands AN - OPUS4-2512 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kuhmann, J. A1 - Harde, P. A1 - Pech, O. A1 - Pittroff, W. A1 - Preuß, A. A1 - Adolphi, B. A1 - Wirth, Thomas A1 - Österle, Werner ED - Reichl, H. T1 - Fluxless flip-chip bonding for the photonic assembly - comparison between evaporated SnPb (60/40) and AuSn (80/20) solder T2 - 5th International Conference on Micro-Electro-, -Opto-, -Mechanical Systems and Components CY - Potsdam, Germany DA - 1996-09-17 PY - 1996 SN - 3-8007-2200-3 VL - 5 SP - 91 EP - 97 PB - VDE-Verl. CY - Berlin AN - OPUS4-2544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Urban, Ingrid A1 - Dörfel, Ilona A1 - Österle, Werner A1 - Schierhorn, Eike T1 - Interfaces between hard coating systems and substrates T2 - 11th European Conference on Electron Microscopy (EUREM-11) CY - Dublin, Ireland DA - 1996-08-26 PY - 1996 SN - 2-9600163-0-0 PB - CESM, Committee of European Societies of Microscopy CY - Brussels AN - OPUS4-2545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ressel, P. A1 - Österle, Werner A1 - Urban, Ingrid A1 - Klein, A. A1 - Vogel, K. A1 - Kräutle, H. T1 - Transmission electron microscopy study of rapid thermally annealed Pd/Ge contacts on In0.53Ga0.47As N2 - Phase formation in rapid thermally annealed Pd/Ge contacts on In0.53Ga0.47As has been investigated by means of cross-sectional transmission electron microscopy, convergent-beam electron diffraction, and energy-dispersive x-ray analysis. Solid-phase regrowth is observed to occur similarly as in Pd/Ge contacts on GaAs or InP. The reaction starts at low temperatures with the formation of an amorphous Pd–In–Ga–As layer, which crystallizes at elevated temperatures yielding hexagonal Pd4In0.53Ga0.47As being first described in this work. At temperatures .250 °C, this phase decomposes due to epitaxial solid-phase regrowth of In0.53Ga0.47As and formation of Pd–Ge phases. The stable composition is reached at temperatures .350 °C with excess Ge diffused through top Pd–Ge to the contact interface and growing epitaxially on the semiconductor. KW - Semiconductor KW - Thin film contact layer KW - Electron microscopy KW - Intermetallic phases PY - 1996 DO - https://doi.org/10.1063/1.363348 SN - 0021-8979 VL - 80 IS - 7 SP - 3910 EP - 3914 AN - OPUS4-38537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Jiao, Feng A1 - Österle, Werner A1 - Portella, Pedro Dolabella A1 - Ziebs, Josef T1 - Cyclic hardening of alloy 800h under biaxial loading T2 - International Congress Stainless Steels '96 ; 2nd European congress CY - Düsseldorf and Neuss, Germany DA - 1996-06-03 KW - Hochtemperaturtechnik KW - Beanspruchung, zyklisch KW - Stahl, austenitisch KW - Legierung 800 H PY - 1996 SN - 3-514-00601-6 SP - 292 EP - 293 PB - Verl. Stahleisen CY - Düsseldorf AN - OPUS4-695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Fedelich, Bernard A1 - Frenz, Holger A1 - Österle, Werner A1 - Ohm, Katrin ED - Lütjering, G. T1 - A stochastic model for LCF small crack growth in a nickel-base superalloy T2 - 6th International Fatigue Congress CY - Berlin, Germany DA - 1996-05-06 PY - 1996 SN - 0-08-042268-3 VL - 96 IS - 2 SP - 1263 EP - 1268 PB - Pergamon CY - Oxford AN - OPUS4-2511 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Österle, Werner A1 - Portella, Pedro Dolabella A1 - Ziebs, Josef A1 - Jiao, Feng ED - Lütjering, G. T1 - Mechanical behaviour of alloy 800h under cyclic biaxial loading T2 - 6th International Fatigue Congress CY - Berlin, Germany DA - 1996-05-06 KW - Legierung KW - Belastung, zyklisch KW - Beanspruchung, mechanisch PY - 1996 SN - 0-08-042268-3 VL - 2 IS - 2 SP - 989 EP - 994 PB - Pergamon CY - Oxford AN - OPUS4-669 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner T1 - Alternative approaches to the microstructure-strength-relationship of LC and HSLA steels T2 - International Conference on HSLA Steels'95 CY - Beijing, China DA - 1995-10-25 PY - 1995 AN - OPUS4-3342 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Merkel, U. A1 - Nebauer, E. A1 - Österle, Werner A1 - Würfl, J. ED - Brueck, S. R. J. T1 - RTA-treated ohmic contacts to GaAs containing WSiN barriers T2 - MRS Spring Meeting on Rapid Thermal and Integrated Processing CY - San Francisco, CA, USA DA - 1995-04-17 PY - 1995 SN - 1-558-99290-1 SN - 0272-9172 N1 - Serientitel: Materials Research Society symposium proceedings – Series title: Materials Research Society symposium proceedings IS - 387 SP - 431 EP - 436 PB - Materials Research Soc. CY - Pittsburgh, Pa. AN - OPUS4-2504 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Österle, Werner ED - Liu, G. T1 - Alternative approaches to the microstructure-strength-relationship of LC and HSLA steels T2 - Third International Conference on HSLA Steels CY - Beijing, PR China DA - 1995-10-25 PY - 1995 SN - 7-504-62091-2 SP - 243 EP - 246 PB - China Science and Technology Press CY - Beijing AN - OPUS4-2506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bettge, Dirk A1 - Österle, Werner A1 - Ziebs, Josef T1 - Temperature dependence of yield strength and elongation of the nickel-base superalloy IN 738 LC and the corresponding microstructural evolution PY - 1995 SN - 0179-4841 SN - 0044-3093 VL - 86 SP - 190 EP - 197 PB - Hanser CY - München AN - OPUS4-2481 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sievert, Rainer A1 - Österle, Werner A1 - Olschewski, Jürgen A1 - Ziebs, Josef T1 - Physical interpretation of a viscoplastic model applied to high temperature performance of a nickel-base superalloy T2 - 7th International Conference on Mechanical Behaviour of Materials CY - The Hague, Netherlands DA - 1995-01-01 PY - 1995 SP - 557 EP - 558 CY - Den Haag AN - OPUS4-2507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Li, Pengxi T1 - Microstructural changes induced by grinding of nickel-base superalloy IN 738 LC and their relationship to machining parameters PY - 1994 SN - 0179-4841 SN - 0044-3093 VL - 85 SP - 20 EP - 27 PB - Hanser CY - München AN - OPUS4-2477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner T1 - Microstructure strength relationships for LC and HSLA steels PY - 1994 SN - 0177-4832 VL - 65 SP - 338 EP - 344 PB - Verl. Stahleisen CY - Düsseldorf AN - OPUS4-2478 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Urban, Ingrid A1 - Nebauer, E. T1 - Alloying reactions of Au-Ni-Ge ohmic contacts to n-GaAs PY - 1994 SP - 781 EP - 782 CY - Les Ulis AN - OPUS4-2479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Li, Pengxi T1 - Development of nanocrystalline microstructures in nickel-base superalloys by grinding and mechanical alloying T2 - 10th European Congress on Electron Microscopy (EUREM) CY - Granada, Spain DA - 1992-09-07 PY - 1992 SP - 313 EP - 314 CY - Stockholm AN - OPUS4-2472 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Gesatzke, Wolfgang A1 - Byrne, G. T1 - TEM study on the effect of machining on the microstructure of a soft magnetic Ni76Fe17Cu5CrMo2 alloy PY - 1991 SN - 0179-4841 SN - 0044-3093 VL - 82 SP - 902 EP - 906 PB - Hanser CY - München AN - OPUS4-2470 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aurich, Dietmar A1 - Österle, Werner T1 - On the combination of elementary strengthening mechanisms in a microalloyed steel PY - 1990 SN - 0863-4947 VL - 14 SP - 109 EP - 115 PB - Akad.-Verl. CY - Berlin AN - OPUS4-2458 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Österle, Werner ED - Hornbogen, E. ED - Jost, N. T1 - Microstructure strength relationship of low carbon martensite T2 - 1st European Conference on Martensitic Transformation in Science and Technology CY - Bochum, Germany DA - 1989-01-01 PY - 1989 SN - 3-88355-153-8 SP - 465 EP - 472 PB - DGM Informationsges. CY - Oberursel AN - OPUS4-2457 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Cho, C.-C. T1 - The role of grain size and ferrite substructure in respect to mechanical properties of an HSLA steel N2 - Several heat treatments were applied to an HSLA steel on type StE460 (German standard) to produce four ferrite substructures of different strength and at least two different grain sizes respectively. Whereas the ferrite substructure has a strong influence on yield strength the effect of grain size was negligible though probably to some extent masked by different pearlite volume fractions. The different strength levels could be explained by regarding the arrangement of dislocations and vanadium carbonitride particles and their mutual interaction. Increasing both grain size and pearlite volume fraction leads to a remarkable shift of transition temperature T sub 27J which was further enhanced by increasing ferrite strength. 16 ref.--AA PY - 1986 SN - 0177-4832 VL - 57 IS - 7 SP - 340 EP - 343 PB - Verl. Stahleisen CY - Düsseldorf AN - OPUS4-2452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Österle, Werner A1 - Gesatzke, Wolfgang ED - Hansen, N. T1 - Investigation of the recovery process during long-term annealing of a 2.25Cr-1Mo steel T2 - 7th Risø International Symposium on Metallurgy and Materials Science ; 7th Risø International Symposium on Annealing Processes - Recovery, Recrystallization and Grain Growth CY - Roskilde, Denmark DA - 1986-09-08 PY - 1986 SN - 87-550-1250-7 VL - 7 SP - 481 EP - 485 PB - Risø National Laboratory CY - Roskilde, Denmark AN - OPUS4-2453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner ED - Brakman, C. T1 - Influence of temperature and impurity content on the development of texture and microstructure of cold-rolled iron T2 - 7th International Conference on Textures of Materials (ICOTOM) CY - Noordwijkerhout, Netherlands DA - 1984-09-17 PY - 1984 VL - 7 SP - 123 EP - 128 PB - Netherlands Society for Materials CY - Zwijndrecht AN - OPUS4-2393 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Wever, H. A1 - Bunge, H. T1 - Development of microstructure and texture of cold-rolled a iron N2 - Optical and electron metallography have been used to investigate the development of different microstructures in Armco Fe after rolling reductions between 0 and 90%. Simultaneously, the orientation distribution functions have been calculated from pole figures obtained by X-ray diffraction. Different stages of texture development could be assigned to typical microstructures. Strain inhomogeneities, such as microbands and shear bands, caused some broadening of the texture and a slight deviation of one skeleton line from the predicted fibre texture component. The decomposition of orientations near {111} < 121 > , and the strengthening of {211} < 011 > after high rolling reductions, was not due to mechanical twinning but could rather be explained by assuming {211} < 111 > slip. 30 ref.--AA PY - 1983 DO - https://doi.org/10.1179/030634583790420772 SN - 0306-3453 SN - 0026-0673 VL - 17 SP - 333 EP - 340 PB - Metals Society CY - London AN - OPUS4-2389 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Österle, Werner A1 - Gesatzke, Wolfgang ED - Bilde-Sørensen, J. T1 - Dislocation-particle interaction during secondary hardening and yielding of HSLA steel T2 - 4th International Symposium on Metallurgy and Materials Science ; 4th International Symposium on Deformation of Multi-phase and Particle Containing Materials CY - Risø, Denmark DA - 1983-09-05 PY - 1983 SN - 87-550-0946-8 VL - 4 SP - 473 EP - 478 PB - Risø National Laboratory CY - Roskilde AN - OPUS4-2391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Gesatzke, W. T1 - Dislocation particle interaction during secondary hardening and yielding of HSLA steel T2 - Riso International Symposium on Metallurgy and Material Science CY - Roskilde, Denmark DA - 05.09.1983 PY - 1983 SP - 473 EP - 478 AN - OPUS4-36051 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Wever, H. A1 - Bunge, H. T1 - Development of microstructure and texture of cold rolling α iron PY - 1983 SN - 0026-0681 IS - 17 SP - 333 EP - 340 PB - Maney Publ. CY - London, UK AN - OPUS4-36056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -