Shrinkage of ZrO2 green bodies manufactured by vat photopolymerization 3D printing

Abstract

The scope of application of ceramic materials is increasingly widening. Additive manufacturing techniques assist in the production of ceramic materials. Photopolymerization 3D printing technology is one of the most widespread processes of manufacturing articles of complex forms. In this paper, the dilatometric analysis is used to study the shrinkage process of green bodies manufactured from zirconia on a 3D printer. It is shown that shrinkage of green bodies is characterized by the same properties as shrinkage of powder compacts obtained by a conventional ceramic method. After the removal of the polymer binder, the maximum shrinkage rate is observed at the heating stage between 1223 and 1239 °C. The shrinkage process intensively continues during the successive isothermal sintering. Shrinkage grows with increasing sintering temperature and exposure time. Porosity of the green body gradually reduces while sintering. Density, porosity and microhardness of zirconia ceramics sintered from the green body at 1550 °C annealing for 6 h, are detected as 4.7 g/cm³, 12.5% and 4.3 GPa, respectively. The obtained results can be used to fabricate zirconia ceramics with specified density and porosity in certain engineering applications.