TY - CONF A1 - Falkenberg, Rainer A1 - Charmi, Amir T1 - Virtual-lab-based determination of a macroscopic yield function for additively manufactured parts N2 - This work presents a method for the yield function determination of additively manufactured parts of S316L steel. A crystal plasticity model is calibrated with test results and used afterwards to perform so-called virtual experiments, that account for the specific process-related microstructure including crystallographic and morphological textures. These simulations are undertaken on a representative volume element (RVE), that is generated from EBSD/CT-Scans on in-house additively manufactured specimen, considering grain structure and crystal orientations. The results of the virtual experiments are used to determine an anisotropic Barlat yield function, that can be used in a macroscopical continuum-sense afterwards. This scale-bridging approach enables the calculation of large-scale parts, that would be numerically too expensive to be simulated by a crystal plasticity model. T2 - 3. Tagung des DVM-Arbeitskreises Additiv gefertigte Bauteile und Strukturen CY - Berlin, Germany DA - 07.11.2018 KW - Virtual experiments KW - Additive manufacturing KW - Anisotropy KW - Crystal plasticity KW - Scale-bridging PY - 2018 AN - OPUS4-46895 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lüchtenborg, Jörg A1 - Mühler, T. A1 - Zocca, Andrea A1 - Günster, Jens T1 - Additive Manufacturing of Dense Ceramics with Laser Induced Slip Casting (LIS) N2 - Most additive manufacturing processes which produce dense ceramics are nowadays limited in size because of inevitable post-processing steps like for example binder removal in stereolithography. The additive manufacturing of voluminous ceramic parts is realized by powder bed based processes which, however, generate parts with residual porosity. Via infiltration these parts can be processed to dense parts like for example SiC but this is not possible for all ceramics like for example Si3N4. There is a lack of methods for the additive manufacturing of dense voluminous parts for most ceramics. We have developed a new additive manufacturing technology, the Laser Induced Slip casting (LIS), based on the layerwise deposition of slurries and their local drying by laser radiation. Laser Induced Slip casting generates ceramic green bodies which can be sintered to dense ceramic components like traditional formed ceramic powder compacts. We will introduce the LIS technology, green bodies and sintered parts will be shown and their microstructure and mechanical properties will be discussed. T2 - CIMTEC 2018 14th Ceramics Congress CY - Perugia, Italy DA - 04.06.2018 KW - Additive Manufacturing PY - 2018 AN - OPUS4-45781 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lüchtenborg, Jörg A1 - Mühler, T. A1 - Zocca, Andrea A1 - Günster, Jens T1 - Additive manufacturing of dense ceramics with laser induced slip casting (LIS) N2 - Most additive manufacturing processes which produce dense ceramics are nowadays limited in size because of inevitable post-processing steps like for example binder removal in stereolithography. The additive manufacturing of voluminous ceramic parts is realized by powder bed based processes which, however, generate parts with residual porosity. Via infiltration these parts can be processed to dense parts like for example SiC but this is not possible for all ceramics like for example Si3N4. There is a lack of methods for the additive manufacturing of dense voluminous parts for most ceramics. We have developed a new additive manufacturing technology, the Laser Induced Slip casting (LIS), based on the layerwise deposition of slurries and their local drying by laser radiation. Laser Induced Slip casting generates ceramic green bodies which can be sintered to dense ceramic components like traditional formed ceramic powder compacts. We will introduce the LIS technology, green bodies and sintered parts will be shown and their microstructure and mechanical properties will be discussed. T2 - yCAM (Young Ceramists Additive Manufacturing Forum) CY - Padua, Italy DA - 03.05.2018 KW - Additive manufacturing PY - 2018 AN - OPUS4-45782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rockenhäuser, Christian A1 - Skrotzki, Birgit T1 - The long-term ageing process of alloy 2618A N2 - The long-term ageing process of alloy 2618A was introduced and discussed The dark-field transmission electronmicroscopical resilts werde shown and evaluated regarding the precipitate radii. The influence of the precipitate radii regarding ageing was used for a preliminary ageing assessment. T2 - 19th International Microscopy Congress (IMC19) CY - Sydney, Australia DA - 09.09.2018 KW - Alloy 2618A KW - Degradation KW - Coarsening KW - S-phase KW - Dark-field transmission electron microscopy (DFTEM) PY - 2018 AN - OPUS4-46120 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabe, Torsten A1 - Schulz, Bärbel A1 - Hollesch, Martin A1 - Börner, Andreas T1 - Keramikfedern – Herstellung, Eigenschaften und Applikation N2 - Entwickelt wurde eine mehrstufige Fertigungstechnologie (Schruppen, Schlichten, Trennschnitt) zur Herstellung keramischer Federn aus gesinterten Hohlzylindern. Durch Optimierung von Maschinenparametern, Schleifscheiben sowie Werkstück- und Werkzeugaufnahmen ist es gelungen, Federn aus Hochleistungskeramik (Aluminiumoxid und Zirkonoxid) mit hoher Kanten- und Oberflächenqualität reproduzierbar herzustellen. Eine hohe Variabilität bezüglich Außen- und Innendurchmesser, Steigung, Windungsquerschnitt und Abstand zwischen den Windungen ermöglicht es, die Federkonstante über drei Größenordnungen zu variieren. Untersucht wurden Federstabilität und Spannungs-Dehnungs-Verhalten unter konstanter und zyklischer Druckbelastung sowie die thermomechanische Stabilität der Keramikfedern. Aluminiumoxid-Federn können bis etwa 800°C, Zirkonoxid-Federn bis etwa 600°C ohne bleibende geometrische Verformung eingesetzt werden. Unter konstanter Spannung zeigen Federn aus Y-stabilisiertem TZP (Zirkonoxid)-Werkstoffen, von anderen Keramikwerkstoffen abweichend, bei Raumtemperatur eine zeitabhängige, elastische, Verformung (Superelastizität), die nach Entlastung über einen Zeitraum von mehreren Stunden reversibel verläuft. Als Ursache wird eine spannungsinduzierte reversible Phasenumwandlung zwischen austenitischer (tetragonales ZrO2) und martensitischer (monoklines ZrO2) Phase postuliert. Diskutiert wird das Anwendungspotenzial der entwickelten Federn für kapazitive keramische Federsensoren für Gravimeter und Wägetechnik. T2 - AK-Sitzung "Keramikbearbeitung" des Fraunhofer IPK CY - Berlin, Germany DA - 27.09.2018 KW - Keramikfeder KW - Spannungs-Dehnungs-Verhalten KW - Zyklische Belastung KW - Thermomechanische Eigenschaften KW - Fertigungstechnologie PY - 2018 AN - OPUS4-46231 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina A1 - Balzer, R. A1 - Kiefer, P. A1 - Müller, Ralf A1 - Reinsch, Stefan A1 - Behrens, H. A1 - Deubener, J. T1 - The influence of volatile constituents on mechanical properties of glasses N2 - Im Rahmen des Young Researcher Day des SPP1594 wurden die bisherigen Inhalte der Projekte zusammengefasst und vorgetragen. T2 - Annual Meeting and Young Researcher Day CY - Jena, Germany DA - 11.09.2018 KW - Glass KW - Crack growth KW - Vickers KW - DCB KW - Water speciation PY - 2018 AN - OPUS4-46728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tielemann, Christopher A1 - Reinsch, Stefan A1 - Patzig, C. A1 - Höche, T. A1 - Busch, R. T1 - Surface Initiated Microstructure Formation in Glass -Ceramics N2 - Übersicht zur Oberflächeninitiierten Mikrostrukturbildung in Glasoberflächen. Dabei wird auf die Kristallvorzugsorientierung senkrecht zur Oberfläche der sich unter Temperatureinfluss behandelten Glasproben eingegangen. Zudem werden die ersten Experimente zur Eingrenzung des Ursprungs dieser Orientierung vorgestellt. N2 - Overview about the surface initiated microstructure formation in glass surfaces. Samples which are exposed to a temperature treatment, can develop a crystalline microstructure above Tg at the surface. These separated crystals can be preferably oriented towards the surface of the sample. First experiments about the origin of these orientation phenomenon as well as the potentially causing mechanisms are presented and discussed within the presentation. T2 - AK Glasig-kristalline Multifunktionswerkstoffe 2019 CY - TU Clausthal, Germany DA - 21.02.2019 KW - Orientation KW - Glass KW - Crystallization KW - Diopside PY - 2019 AN - OPUS4-47537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hlavacek, Petr A1 - Mühler, T. A1 - Lüchtenborg, Jörg A1 - Sturm, Patrick A1 - Gluth, Gregor A1 - Kühne, Hans-Carsten A1 - Günster, Jens T1 - Additive manufacturing of geopolymers by local laser curing N2 - For the additive manufacturing of large components typically powder-based methods are used. A powder is deposited layer by layer by means of a recoater, then, the component structure is printed into each individual layer. We introduce here the new method of local laser drying, which is a suspension-based method specially developed for the manufacturing of large voluminous ceramic parts. The structure information is directly written into the freshly deposited layer of suspension by laser drying. Initially, the technology was developed for ceramic suspensions, however, first experiments with geopolymers reveal a high potential for this class of materials. Metakaolin, fly ash and lithium aluminate-based one-part geopolymers were used in first experiments. The local annealing of the geopolymer slurry results in a drying and crosslinking reaction and, thus, in a local consolidation of the material. First parts made are introduced and their properties are discussed. T2 - CIMTEC 2018 CY - Perugia, Italy DA - 04.06.2018 KW - Additive manufacturing KW - Laser curing KW - Geopolymers PY - 2018 AN - OPUS4-47447 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Babutzka, Martin A1 - Trappe, Volker A1 - Pittner, Andreas A1 - Krankenhagen, Rainer A1 - Kühne, Hans-Carsten T1 - Vorstellung des Aktivitätsfelds Erneuerbare Energie N2 - Auf der Beiratssitzung des TF Energie wurde das Aktivitätsfeld Erneuerbare Energien in seinem breiten Spektrum (aber selektive Auswahl) vorgestellt. T2 - Beiratssitzung TF Energie CY - BAM Berlin-Adlershof, Germany DA - 09.04.2019 KW - Erneuerbare Energien KW - Windenergie PY - 2019 AN - OPUS4-47751 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zocca, Andrea A1 - Lüchtenborg, Jörg A1 - Günster, Jens A1 - Diener, S. A1 - Lima, P. A1 - Katsikis, N. T1 - Layerwise Slurry Deposition for the Additive Manufacturing of Ceramics N2 - In powder bed Additive Manufacturing (AM) technologies, a part is produced by depositing and piling up thin powder layers. In each layer, the cross section of the object to build is defined by locally consolidating the powder, by sintering/melting the material (powder bed fusion technologies) or by ink jetting a binder (binder jetting technologies). These are already leading AM technologies for metals and polymers, thanks to their high productivity and scalability. The application of these techniques to most ceramics has been challenging so far, because of the challenges related to the deposition of homogeneous powder layers when using fine powders. In this context, the "layerwise slurry deposition" (LSD) has been developed as a layer deposition method which enables the use of SLS/SLM and 3DP technologies for advanced ceramic materials. LSD consists in the layer-by-layer deposition of a ceramic slurry by means of a doctor blade. Each layer is deposited and dried to achieve a highly packed powder layer. The LSD offers high flexibility in the ceramic feedstock used, especially concerning material and particle size, and enables the production of parts with physical and mechanical properties comparable to pressed or slip-casted parts. In this presentation, the LSD technique will be introduced and several examples of application to porcelain, SiC and alumina products will be reported. T2 - ICACC 2019 - 43rd International Conference and Exposition on Advanced Ceramics and Composites CY - Daytona Beach, FL, USA DA - 27.01.2019 KW - Additive Manufacturing KW - Ceramic KW - Layerwise KW - Slurry PY - 2019 AN - OPUS4-47865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -