SUN Jian, LI Jiake, WANG Yanxiang, ZHU Haixiang
(School of Material Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China)

Abstract: Silicon dioxide-based electroceramics were prepared, using discarded quartz crucible, kaolin, feldspar and bauxite as starting materials. The effects of batch formula and firing temperature on phase composition, microstructure, mechanical performance and dielectric properties of silicon dioxide-based electroceramics were investigated by XRD, SEM, material testing machine and dielectric constant testing instrument. The results show that silicon dioxide-based electroceramics with good dielectric and mechanical properties are obtained when the batch formula is composed of 40% discarded quartz crucible powder, 40% kaolin, 15% feldspar and 5% bauxite, the firing temperature is 1300 ℃ and the holding time is 30 min. The dielectric constant (εr) and dielectric loss (tanθ) of silicon dioxide - based electroceramic are 7.15 and 19.50×10^-3, respectively. The bending strength and thermal shock resistance (ΔT ) of silicon dioxide - based electroceramic are 76.45 MPa and above 180 ℃, respectively.

Key words: discarded quartz crucible; silicon oxide - based ceramics; dielectric properties; mechanical performance