Articles
  • Synthesis of low thermal expansion ceramics prepared from pyrophyllite and lithium source
  • Yeong-Gyun Yanga, Suk-In Jeongb, Ji-Yeon Kwakc and Sang-Jin Leea,b,*
  • a Department of Advanced Materials Science and Engineering, Mokpo National University, Muan 58554, Republic of Korea b Research Institute of Ceramic Industry and Technology, Mokpo National University, Muan 58554, Republic of Korea c Department of Physiology and Biophysics, Inha University College of Medicine, Incheon 22212, Republic of Korea
Abstract
In this study, the low thermal expansion ceramic, petalite (Li2O • Al2O3 • 8SiO2), was synthesized by using pyrophyllite, and their characteristics were examined. Pyrophyllite is consisted of SiO2 and Al2O3, which are the main component of petalite. For the synthesis of petalite, Li2CO3 or LiOH • H2O were used as a source of Li2O. In the mixing ratio of 6.7 : 1 wt% (pyrophyllite : Li2CO3), fully crystallized petalite was synthesized, and the powder compacts were densified at 1150 oC. Some Li compounds, which have low melting point, caused a formation of liquid phase in the densified samples. The petalite phase was transformed to β-spodumene during heating process, and the sintered petalite showed a negative thermal expansion coefficient of −0.43 × 10- 6/oC. Finally, the experimental results showed that the pyrophyllite is an expected material for the synthesis of low thermal expansion ceramics.

Keywords: Pyrophyllite, Petalite, Thermal expansion coefficient, Lithium carbonate, β-spodumene.

This Article

  • 2016; 17(7): 747-751

    Published on Jul 31, 2016

Correspondence to

  • E-mail: