The authors thank Mr. J. F. Carlotti and Mr. A. Cranio for the experimental assistance.
Microstructure Development and Dielectric Characterization of Forsterite-Based Ceramics from Silicone Resins and Oxide Fillers†
Article first published online: 9 APR 2014
© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Engineering Materials
Special Issue: Advanced Ceramics and Coating Processing
Volume 16, Issue 6, pages 806–813, June 2014
How to Cite
Bernardo, E., Fiocco, L., Giffin, G. A., Di Noto, V. and Colombo, P. (2014), Microstructure Development and Dielectric Characterization of Forsterite-Based Ceramics from Silicone Resins and Oxide Fillers. Adv. Eng. Mater., 16: 806–813. doi: 10.1002/adem.201400125
- Issue published online: 11 JUN 2014
- Article first published online: 9 APR 2014
- Manuscript Accepted: 18 MAR 2014
- Manuscript Received: 11 MAR 2014
Forsterite (Mg2SiO4) ceramics are excellent candidate materials for components operating with high-frequency electromagnetic waves, due to their low dielectric losses. In this paper, we discuss a novel processing approach for the production of forsterite monoliths based on the mixing of silicone resins with MgO nano-sized particles. The interaction between the nano-sized filler and the silica provided by the oxidative decomposition of silicones was so effective that forsterite formed at only 800 °C, i.e., just above the transformation temperature of the preceramic polymers. The approach based on silicones modified with oxide fillers was followed also when trying to suppress undesirable phases, such as unreacted MgO and enstatite (MgSiO3); in particular TiO2, added in form of nano- and micro-sized powders, was useful both as active filler, promoting the formation of forsterite solid solution and Mg-titanates, and as passive filler, leading to a forsterite/rutile composite. Both Ti-doped forsterite and the composite featured interesting dielectric characteristics (low dielectric constant, high quality factor), despite the presence of some residual porosity (≈15%, after firing at 1100 °C).