Talks and Poster Presentations (without Proceedings-Entry):
G. Mitteramskogler, R. Felzmann, S. Gruber, J. Stampfl, Ebert, W. Wachter, J. Laubersheimer:
"Light Curing Strategies for Lithography-Based Additive Manufacturing of Customized Ceramics";
Talk: EUROMAT 2013,
Lithography-based additive manufacturing techniques (AMT) are increasingly becoming the technology of choice for the fabrication of customized ceramic parts. It is a multidisciplinary field combining polymer chemistry, mechanical engineering and a fundamental knowledge of the whole process chain. The DLP-process (Digital Light Processing) used in this study creates a part by stacking up layer upon layer. The printing of a layer relies on the selective polymerization of a photosensitive ceramic-filled resin up to a solid loading of around 50 vol.%. Materials that can be used range from engineering ceramics (alumina) to biocompatible ceramics (tricalcium phosphate or bioactive glass). The native resolution of the DLP process depends on the light engine´s DMD (Digital Mirror Device) chip and the optics used. Currently it is possible to print 3D structures with a spatial resolution down to 25μm. The light engine allows for customization of the light curing strategy for each voxel (3D pixel) of the currently exposed layer. In this work, exposure strategies for inner and outer voxels are presented. On the one hand, curing strategies are used to create a spatial sub-pixel resolution by controlled overgrowth of the geometry. On the other hand, the curing strategies can be used to minimize shrinkage stress originating from the photopolymerization. It could be shown that shrinkage stress is directly linked to the appearance of stress related cracks in the green body during thermal treatment. By appropriate processing, fully dense alumina and zirconia parts with excellent biaxial strength were realized.
Biomaterials; Photopolymerization; Digital Light Processing; Ceramic filler; Complex geometries
Electronic version of the publication:
Created from the Publication Database of the Vienna University of Technology.