Ingenieurwissenschaften und zugeordnete Tätigkeiten
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- Corrosion (7)
- Steel (5)
- CO2 (4)
- Additive Manufacturing (3)
- Carbon steel (3)
- Laser Metal Deposition (3)
- Laser implantation (3)
- Surface texturing (3)
- TiB2 (3)
- AISI D2 (2)
Organisationseinheit der BAM
- 9 Komponentensicherheit (27)
- 9.3 Schweißtechnische Fertigungsverfahren (20)
- 7 Bauwerkssicherheit (16)
- 5 Werkstofftechnik (9)
- 6 Materialchemie (8)
- 7.6 Korrosion und Korrosionsschutz (8)
- 5.1 Mikrostruktur Design und Degradation (7)
- 4 Material und Umwelt (6)
- 8 Zerstörungsfreie Prüfung (6)
- 7.1 Baustoffe (4)
- 9.4 Integrität von Schweißverbindungen (4)
- 4.2 Material-Mikrobiom Wechselwirkungen (3)
- 6.1 Oberflächen- und Dünnschichtanalyse (3)
- 6.2 Material- und Oberflächentechnologien (3)
- 9.5 Tribologie und Verschleißschutz (3)
- 3 Gefahrgutumschließungen; Energiespeicher (2)
- 4.5 Kunst- und Kulturgutanalyse (2)
- 6.6 Physik und chemische Analytik der Polymere (2)
- 7.4 Baustofftechnologie (2)
- 7.5 Technische Eigenschaften von Polymerwerkstoffen (2)
- 8.0 Abteilungsleitung und andere (2)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (2)
- 8.4 Akustische und elektromagnetische Verfahren (2)
- 2 Prozess- und Anlagensicherheit (1)
- 2.4 Prüfung und Bewertung von Explosivstoffen/Pyrotechnik (1)
- 3.1 Sicherheit von Gefahrgutverpackungen und Batterien (1)
- 3.4 Sicherheit von Lagerbehältern (1)
- 4.1 Biologische Materialschädigung und Referenzorganismen (1)
- 5.2 Metallische Hochtemperaturwerkstoffe (1)
- 5.3 Polymere Verbundwerkstoffe (1)
- 6.5 Synthese und Streuverfahren nanostrukturierter Materialien (1)
- 7.0 Abteilungsleitung und andere (1)
- 7.2 Ingenieurbau (1)
- 9.0 Abteilungsleitung und andere (1)
The determination of mechanical properties of welded Steel structures such as strength or ductility is a subject of high interest for the majority of Companies in the area of metal Processing. The material Parameters can be obtained by performing the tensile test on the samples made from a part of a component. In some cases, it is highly expensive to produce the tensile specimens especially from the weld metal, which contains different type of microstructure such as weld seam or heat affected zone in an extremely small area. Therefore, a method is described in this paper to determine the material Parameters of high strength Steel structures and welded joints locally and without any additional effort to perform the tensile test. In this method, instrumented indentation technique (IIT), an indenter is pushed on the flat surface of a specimen in a certain period of time and simultaneously the applied force and the corresponding indentation path are measured. The data related to the force-indentation diagram is given as input to an artificial neural network (ANN) to obtain the material Parameters. The ANN can be trained by generating the large qualitative data sets with numerical Simulation of the IIT procedure. The Simulation must be run several times with the different material model parameter sets to generate the numerous
force-indentation diagrams as the inputs of ANN. Then, the trained ANN is validated by performing the IIT on the welded joints and comparing the obtained material Parameters from ANN with the tensile test.
Consequently, the mechanical properties of welded joints can be determined by performing the IIT and evaluating the resulting data by the ANN.
Over the last years, the weight of modern car bodies has risen significantly due to the increasing customers’ demand for comfort and safety equipment. However, this ongoing trend leads to an increasing fuel consumption and thus to higher carbon dioxide emissions. In order to counteract these problems, hot stamping has been established in the automotive industry as a key technolo-gy for lightweight construction, regarding the manufacturing of safety-relevant car body compo-nents. Hot stamped parts are commonly made out of boron-manganese steel 22MnB5, which is initially austenized and subsequently formed and quenched in one process step. As a result, geo-metrical complex structures with an ultimate tensile strength of 1500 MPa are generated. The surfaces of the workpieces are coated with an Al-Si layer to avoid oxide scale formation and to ensure corrosion protection. However, the coating system leads to an increased adhesive wear on the tool surface due to the high thermo-mechanical tool stresses. Therefore, a time and cost con-suming rework of the hot stamping tools is required. The aim of this study is to increase the tribological performance of hot stamping tools by using a laser implantation process. This tech-nique allows the ma-nufacturing of separated, elevated and dome-shaped microstructures on the tool surface in consequence of a localized dispersing of hard ceramic particles by pulsed laser radiation. The generated surface features offer great potential for reducing the tribological load, due to their high hardness and wear resistance. For this purpose, the friction coefficient of un-modified and laser implanted tool surfaces were examined and compared by using a modified pin-on-disk test. In addition, the surfaces were analyzed by optical measurements in order to quantify the amount of wear.
The development of hydrogen technologies is a key strategy to reduce greenhouse gas emission worldwide. Power-to-Gas is a challenging solution, in which hydrogen and methane can be used in mobility, industry, heat supply and electricity generation applications. This presentation deals with the tribological behaviour of polymer materials in hydrogen and methane, both in gas and in liquefied form.
Since the early drafting of the European standards for civil explosives, harmonised under directive 93/15/EEC and 2014/28/EU, blasting technology has developed notably. This is particularly evident for electronic detonators and electronic firing systems, and the EU commission agreed to initiate a standardisation initiative, also noting that the currently existing document on electronic detonators is “only” a Technical Specification (CEN/TS). This paper addresses the current activities in the area of standardisation. The EU is about to launch a formal standardisation request to cover the most recent technological developments not addressed by the current standards. The request would also include various adjustments of references to the new Directive for civil explosives, and in addition the task of developing a Technical Specification for on-site mixed explosives and corresponding manufacturing units. The latter has been included to address the nowadays frequently found mobile production on the basis of ammonium nitrate prills or emulsions.
3D microstructures with sub-micron resolution can be manufactured in additive manner applying multi-photon laser structuring technique. This paper is focused on the incorporation of superparamagnetic iron oxide nanoparticles into the photoresist in order to manufacture micrometer-sized devices featuring a magnetic moment. The aim of the project is to achieve untethered actuation of the presented objects through externally applied magnetic fields. Future medical application scenarios such as drug delivery and tissue engineering are targeted by this research.
The presence of polycarboxylate ether (PCE) based superplasticizers (SPs) has enormous influence on the early hydration of cement. C3A as the most reactive phase of Portland cement plays a significant role in early hydration reactions and affects the rheological performance. Therefore, this paper presents experimental results about the influence of delayed addition of PCEs on the Hydration of cement and C3A-gypsum pastes investigated by isothermal heat flow calorimetry. Complementary in-situ XRD was carried out on C3A pastes to analyze hydration and phase changes related to the addition of PCE.
Cement pastes with a delayed addition of PCE showed less Retardation compared to simultaneous addition. The alteration caused by PCE is much more pronounced for C3A-gypsum mixes. With a delayed addition of SP, the hydration of C3A is less retarded or even accelerated. It is obvious that there is less retardation the later the addition of SP. Furthermore, the PCE alter the hydration of C3A when added delayed and exhibit changes in kinetics and hydration rates. XRD results showed that more C3A is dissolved in the presence of PCE. Also, the gypsum depletion occurs earlier in the presence of PCE and even faster with delayed addition. Without PCE AFm starts to form just after the gypsum depletion. However, in the presence of PCE AFm already starts to form at the beginning of the hydration. Due to the faster gypsum depletion in the presence of PCE, also the transformation from ettringite into AFm begins earlier, but takes longer as without SP.
In this poster we will present some results of a research projects dealing with Arabic recipes of black inks. To improve conservation practices of Arabic manuscripts we have assessed the feasibility of the recipes collected from many Arabic sources on bookmaking and reproduced the most common inks. Ink samples were then artificially aged and analysed using an array of analytical techniques, mostly non-invasive, in order to build a database of Arabic inks and their ingredients and also to verify the detection limits of the portable equipment employed.
We will show procedures and problems concerning the identification of ink types and ingredients using reflectography (in Vis, IR and UV), X-Ray Fluorescence, Infrared and Raman spectroscopy. The focus will be in particular on squid ink and mixed inks – both in the form of carbon inks with the addition of tannins and of a mixture of carbon and iron gall inks – which are particularly difficult to detect. We will also examine the results of iron gall inks made with iron filings or nails instead of vitriol, the various precursor used to extract gallic acid that are mentioned in the sources as surrogates of gall nuts.
Renowned institutions in the field of tribology combine their testing and analytical capabilities with experts in materials/process information management technology to provide the respective Services in Europe (i-TRIBOMAT). This requires a centralized materials information management system or the standardised capture, consolidation and harmonization of tribological information.
Weathering reference materials (WRMs) are used to characterize the harshness of an exposure, aiming on either reproducibility of a specific exposure or on the comparability between various kinds of natural or artificial weathering exposure.
The materials that are used as weathering reference materials differ in their sensitivities (as well as in interactions and interferences of the latter), conditioned by the different processes which lead to the respective property change. It is also essential to take into account the necessary measurement equipment for the respective property change, in order to allow timely intervention.
What are the key issues on choosing a weathering reference material?
What can be learned from the weathering reference materials, investigated so far?
Possibilities and limitations are discussed on the basis of existing weathering reference materials. Conclusions are drawn, for establishing new weathering reference materials.
By means of a small-scale truss bridge, the ability of the Measurement- and Model-based Structural Analysis to detect and localize damage was examined. Although there was no noteworthy difficulty in detecting damage, it turned out that damage localization responds sensitively to systematic influences, i.e. non-modelled properties of the mechanical model. Therefore, another experiment is being conducted to re-examine the Measurement- and Model-based Structural Analysis. For this purpose, the bending test is carried out as it has been already theoretically respectively numerically discussed. In this attempt, the systematic influences such as residual stress are kept as low as possible.