Monoclinic Zirconia Bodies by Thermoplastic Ceramic Extrusion |
| |
Authors: | Gerd Scheying,Ingrid Wü hrl,Ulrich Eisele,Ralf Riedel |
| |
Affiliation: | Department of Materials Science, Darmstadt University of Technology, 64287 Darmstadt, Germany;Corporate Materials Research, Robert Bosch GmbH (FV/FLW), 70049 Stuttgart, Germany |
| |
Abstract: | Two ultrafine, undoped ZrO2 powders with median primary particle sizes of 9 and 25 nm were used to prepare ceramic suspensions for thermoplastic extrusion. The organic vehicle consisted of an industrial-grade poly(ethylene- co -vinyl acetate) (EVA) or polyethylene (PE-HD) and decanoic acid as a dispersing agent. The powder volume loadings achieved were 44% and 52% by volume for the two powders, respectively. The amount of dispersant needed was calculated from a new model based on available chemisorption sites on the powder surface. Mixing and extrusion were conducted using a conventional modular plastic processing unit. Green bodies were dewaxed up to 450°C in an inert atmosphere and sintered to full density in air at 1060° and 1100°C, respectively. Analysis of the ceramic phase content and the microstructure of the bodies is presented. |
| |
Keywords: | zirconia extrusion |
|
|