Achieving near-zero sintering shrinkage in pottery through anorthite crystallization
MIKI I. 4, ATSUNORI S. 3, DONG H. 1, TAKASHI A. 2, NOBUAKI K. 3
1 Saga University, Saga, Japan; 2 Tokyo University of Technology, Tokyo, Japan; 3 Saga Ceramics Research Laboratory, Saga, Japan; 4 Kyushu University, Fukuoka, Japan
The precise control of the geometry of pottery is a challenge due to the undesirable shrinkage and deformation observed after firing. In this study, near-zero sintering shrinkage pottery (NZS), with less than 2.0% sintering shrinkage (SS) and small pyroplastic deformation (Pyroplastic deformation index < 1.5Í10-6Ÿmm-1), was developed by quantitative examination of the alumina and wollastonite addition. Wollastonite promotes anorthite crystallisation, thereby preventing sintering shrinkage at ~1200 °C. The mechanism for the suppressed liquid-phase sintering of the pottery was also analysed. Moreover, NZS were obtained after firing at 1300 °C with a specific phase composition for suppressing the pyroplastic deformation. Thus, NZS was successfully prepared through liquid sintering from natural minerals. This study provides a guide for the fabrication of porous pottery and ceramic tileswith precise dimension and geometry in a wide firing temperature. Additionally, it is also important for reducing the production loss in huge pottery and large-scale production by countering the sintering shrinkage.
Acknowledgement
This work was partially supported by JSPS KAKENHI Grant number 21K12901, Grants of Nippon Sheet Glass Foundation for Materials Sciences and Engineering, and Iketani Science and Technology Foundation.