Anmelden

Open Access

  • Startseite
  • Suchen
  • Browsen
  • Veröffentlichen
  • Hilfe

Filtern

Autor

  • Günster, Jens (96)
  • Zocca, Andrea (20)
  • Wirth, Cynthia (13)
  • Colombo, P. (9)
  • Mühler, T. (9)
  • Heinrich, J.G. (8)
  • Yao, Dongxu (7)
  • Bischoff, S. (6)
  • Bossert, J. (6)
  • Brinkmann, O. (6)
+ weitere

Erscheinungsjahr

  • 2020 (9)
  • 2019 (11)
  • 2018 (9)
  • 2017 (10)
  • 2016 (8)
  • 2015 (18)
  • 2014 (15)
  • 2013 (11)
  • 2012 (3)
  • 2011 (2)
+ weitere

Dokumenttyp

  • Zeitschriftenartikel (62)
  • Vortrag (29)
  • Posterpräsentation (3)
  • Beitrag zu einem Sammelband (1)
  • Beitrag zu einem Tagungsband (1)

Sprache

  • Englisch (70)
  • Deutsch (26)

Referierte Publikation

  • ja (50)
  • nein (46)

Schlagworte

  • Additive manufacturing (15)
  • Additive Manufacturing (11)
  • 3D printing (5)
  • Ceramic (5)
  • Ceramics (5)
  • Additive Fertigung (4)
  • Porosity (4)
  • 3D-Printing (3)
  • Bone regeneration (3)
  • Computed tomography (3)
+ weitere

Organisationseinheit der BAM

  • 5 Werkstofftechnik (60)
  • 5.4 Keramische Prozesstechnik und Biowerkstoffe (60)
  • 8 Zerstörungsfreie Prüfung (9)
  • 8.5 Mikro-ZfP (8)
  • 4 Material und Umwelt (2)
  • 5.1 Materialographie, Fraktographie und Alterung technischer Werkstoffe (2)
  • 6 Materialchemie (2)
  • 7 Bauwerkssicherheit (2)
  • 7.4 Baustofftechnologie (2)
  • 9 Komponentensicherheit (2)
+ weitere

96 Treffer

  • 1 bis 10
  • CSV
  • RIS
  • 10
  • 20
  • 50
  • 100

Sortieren nach

  • Jahr
  • Jahr
  • Titel
  • Titel
  • Autor
  • Autor
Direct Laser Sintering for the Manufacture of Ceramics: Status and Perspective (2012)
Günster, Jens
Additive Manufacture of Ceramics: Status and Perspective (2012)
Günster, Jens
LSD based additive manufacturing of ceramics (2016)
Günster, Jens
The production of ceramic parts by an additive manufacturing process is still a challenging task. Especially in powder-based technologies, such as 3D printing or laser sintering, the feedstock material is commonly spread out as thin layers of a dry powder/granulate by a roller or a shaker system. As consequence the layers are characterized mostly by a low packing rate. On the other hand, from a ceramic processing viewpoint, appreciable densities can be achieved by the use of ceramic slurries. In this context, the so-called Layer-wise Slurry Deposition (LSD) process has been developed. An overview about the LSD process and latest advances in the development of this technology will be presented.
Adapting trabecular structures for 3D printing: an image processing approach based on μCT data (2017)
Homberg, U. ; Baum, D. ; Prohaska, S. ; Günster, Jens ; Krauss-Schüler, Stefanie
Materials with a trabecular structure notably Combine advantages such as lightweight, reasonable strength, and permeability for fl uids. This combination of advantages is especially interesting for tissue engineering in trauma surgery and orthopedics. Bone-substituting scaffolds for instance are designed with a trabecular structure in order to allow cell migration for bone ingrowth and vascularization. An emerging and recently very popular technology to produce such complex, porous structures is 3D printing. However, several technological aspects regarding the scaffold architecture, the printable resolution, and the feature size have to be considered when fabricating scaffolds for bone tissue replacement and regeneration. Here, we present a strategy to assess and prepare realistic trabecular structures for 3D printing using image analysis with the aim of preserving the structural elements. We discuss critical conditions of the printing system and present a 3-stage approach to adapt a trabecular structure from μ CT data while incorporating knowledge about the printing system. In the first stage, an image-based extraction of solid and void structures is performed, which results in voxel- and graph-based representations of the extracted structures. These representations not only allow us to quantify geometrical properties such as pore size or strut geometry and length. But, since the graph represents the geometry and the topology of the initial structure, it can be used in the second stage to modify and adjust feature size, volume and sample size in an easy and consistent way. In the final reconstruction stage, the graph is then converted into a voxel representation preserving the topology of the initial structure. This stage generates a model with respect to the printing conditions to ensure a stable and controlled voxel placement during the printing process.
Additive manufacturing techniques for fabricating complex ceramic components from preceramic polymers (2017)
Colombo, P. ; Schmidt, J. ; Franchin, G. ; Zocca, Andrea ; Günster, Jens
Capsule summary THE MATERIALS Manufacturers can use preceramic polymers to produce ceramic components in a range of compositions using a variety of additive manufacturing technologies. Preceramic polymers even can overcome some of the problems that are intrinsic to additive manufacturing in general. THE APPLICATION Modifying the composition, molecular architecture, and molecular weight of preceramic polymers allows adaptation of these materials to specific processing requirements of individual additive manufacturing technologies. THE OPPORTUNITY Further development of new additive manufacturing technologies, in addition to improvement of existing technologies, will enable manufacturing of advanced ceramic components with enhanced mechanical characteristics and new functional properties.
Mechanistic Studies of Compacted and sintered rock salt (2016)
Swanson, C. ; Böhme, Susanne ; Günster, Jens
This chapter discusses different approaches for the densification of rock salt powders via compaction and sintering, focusing on the use of powder qualities obtained by crunching and milling of the natural rock salt. The chapter also examines the effect of compaction pressure, time and temperature on sintering of rock salt. Natural rock salt samples were crushed and milled in a disc mill to obtain fine powders in an experiment. The hot stage microscope allowed observing the in-situ volumetric shrinkage to be determined during the sintering process by measuring the area of the sample's projection in an optical setup by a CCD camera. Images were collected at a rate of 40 frames per minute. After the application of high pressures, the obtained samples are translucent and show the formation of macroscopic crack. Powder compacts prepared by uniaxial pressing, at different maximum pressures, were annealed at a constant heating rate (10 K min-1) to different maximum temperatures. These experiments were performed in a conventional sintering furnace under ambient atmosphere.
Selective laser sintering in combination with layerwise slurry deposition for the additive manufacture of sic ceramics (2016)
Günster, Jens
Selective laser sintering is a well-established technology for the additive manufacture of metallic and polymeric parts. For the additive manufacture of ceramic parts some examples for its successful application do exist, also. In this context, the selective laser sintering of SiC ceramic powders has been studied extensively in the past. Despite its low sintering activity, SiC is particularly suited for the selective laser sintering process, because of the possibility to form SiO2 at elevated temperatures in oxidizing ambient. The SiO2 formed can act as a binder within the laser sintering process. In the present work densely packed powder beds generated by the Layerwise Slurry Deposition (LSD) technology are selectively sintered by a cw. fiber laser. The layerwise slurry deposition is an innovative process for the deposition of layers in additive manufacturing. A slurry with no or very small organic content is repetitively spread as thin layers on each other by means of a doctor blade. During the deposition process, the ceramic particles settle to form thin layers of about 100 µm which have a high packing density (typical 55-60%). This high powder packing density is the result of a slip casting process: When a layer is deposited on a previously dried porous layer, the water is drawn into the pores by capillary forces. The LSD process therefore shares aspects of tape casting and slip casting. An additional benefit of the LSD technology is the free choice of the size of the ceramic particles used. Compared to the processing of dry flowable powders, especially small particles can be very well processed.
Keramische Prozesstechnik: InTeRview mit Prof. Dr. Jens Günster (2017)
Günster, Jens
Im Rahmen unserer turnusmäßig erscheinenden Rubrik InTeRdisziplinär stellt sich heute Prof. Dr. Jens Günster, Leiter des Fachbereichs "Keramische Prozesstechnik und Biowerkstoffe" bei der Bundesanstalt für Materialforschung und-prüfung, den FRagen der InTeR.
Layerwise slurry deposition of technical ceramics for Additive Manufacturing (2016)
Günster, Jens
The use of water based ceramic slurries as feedstock for the additive manufacture of ceramics has many advantages which are not fully exploit yet. In the layerwise slurry deposition (LSD) process a slurry with no or low organic content is repetitively spread as thin layers on each other by means of a doctor blade. During the deposition, the ceramic particles settle on the previously deposited and dried material to form thin layers with a high packing density (55-60%). The LSD therefore shares aspects both of tape casting and slip casting. The LSD differentiates from the classical powder-based AM layer deposition, which typically achieves with a flowable coarse grained powder a low packing density (35-50%) only, consequently hindering the ability of sintering ceramic parts to full density. The LSD is coupled with the principles of selective laser sintering (SLS) or binder jetting, to generate novel processes which take advantage of the possibility of achieving a highly dense powder-bed. Contrary to the LSD process, which requires drying of each individual layer, the direct interaction of ceramic slurries with intense laser radiation is a promising approach for the additive manufacture of ceramics, also. This presentation will provide a detailed discussion of the specific features of the slurry based processes, potentialities and issues connected to the layer deposition and describe the most recent developments in their application to technical ceramics.
Verfahrensübersicht von keramischem 3D-Druck (2016)
Günster, Jens
Leistungsstarke Verfahren zur additiven Fertigung wie der 3D Druck und das Selektive Lasersintern basieren auf dem Schichtauftrag eines fließfähigen Pulvers. Bei keramischen Pulvern ist eine gute Fließfähigkeit ab einer Partikelgröße von ca. 40 µm gegeben. Bei Pulvern mit zu feinen Partikeln sind die adhäsiven Kräfte zwischen den Partikeln vergleichbar groß wie die Kräfte, die durch die Gravitation auf die Partikel wirken, was einem gleichmäßigen Fließen des Pulvers und somit einem gleichmäßigen Schichtaufbau entgegensteht. Die Verwendung von feineren Pulvern hat jedoch Vorteile, wie z.B. eine bessere Sinteraktivität. Neben der nötigen minimalen Partikelgröße besteht für keramische Werkstoffe ein wesentliches Problem der pulverbasierten Verfahren in der Tatsache, dass das Pulverbett, also das durch Schichtauftrag gestapelte Pulver, eine zu geringe Dichte besitzt. Dies bringt grundsätzlich zwei Nachteile mit sich: zum einen verhindert eine zu geringe Packungsdichte des Pulvers den Aufbau kompakter Grünkörper und letztlich deren Sinterung zu einer dichten Keramik, zum anderen wird im Aufbauprozess das Bauteil durch das Pulverbett nicht ausreichend gestützt. Beim Auftragen einer neuen Pulverschicht kann die bereits verfestigte Struktur im Pulverbett verschoben werden, was zu Defekten in der Struktur bis hin zum vollständigen Verlust der Struktur führt. Aus diesem Grunde ist neben dem Aufbau des zu fertigenden Bauteils u.U. der Aufbau von zusätzlich sogenannten Supportstrukturen gefordert. Diese Supportstrukturen verankern das Bauteil mit der Bauplattform und fixieren es somit im Koordinatensystem des Bauraums der Anlage. Das Entfernen der Supportstrukturen erfordert nach dem eigentlichen additiven Fertigungsprozess einen zusätzlichen Prozessschritt, der zeitaufwendig und kaum zu automatisieren ist, und daher einer autonomen Fertigung, wie sie durch die Additive Fertigung realisiert werden kann, entgegensteht. Es werden unterschiedliche Strategien für die Stabilisierung des Pulverbetts und zur Erzielung einer hohen Packungsdichte der Partikel im Pulverbett aufgezeigt. Neben der Lagenweise SchlickerDeposition (LSD) werden Ergebnisse zur Gas Flow Assisted Powder Deposition vorgestellt.
  • 1 bis 10

OPUS4 Logo

  • Kontakt
  • Impressum
  • Sitelinks