리튬용액침투법에 의한 내열충격성이 향상된 세라믹 제조 |
나상문, 이상진1 |
(주)와이제이씨 1국립목포대학교 신소재공학전공 |
Fabrication of Porcelains Having Improved Thermal Shock Resistance by a Lithium Solution Infiltration Method |
Sang-Moon Na, Sang-Jin Lee1 |
YJC Co., LTD. 1Department of Advanced Materials Science and Engineering, Mokpo National University |
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ABSTRACT |
Porcelain with high thermal shock resistance was successfully fabricated by a lithium solution infiltration method with a lithium hydroxide solution. Lithium hydroxide solutions having various lithium concentrations were infiltrated into pre-sintered porcelain bodies. The porcelain sample infiltrated by the 9 wt% lithium solution and heat treated at $1250^{circ}C$ for 1 h showed a low thermal expansion coefficient of $1.0{times}10^{-6}/^{circ}C$ with excellent thermal shock resistance. The highly thermally resistant porcelain had a well-developed ${beta}$-spodumene phase with the general phases observed in porcelain. Furthermore, the porcelain showed a denser structure of $2.41g/cm^3$ sintering density and excellent whiteness in comparison with commercial thermally resistible porcelains. The lithium hydroxide in the samples readily reacted with moisture, and liquid phase reactants were formed during the fabrication process. In the case of an excess amount of lithium in the sample body, the lithium reactants were forced to the surface and re-crystallized at the surface, leaving large pores beneath the surface. These phenomena resulted in an irregular structure in the surface area and led to cracking in samples subjected to a thermal shock test. |
Key words:
Porcelain, Thermal resistance, ${\beta}$-spodumene, Microstructure, Lithium solution |
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