Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Fabrication of Porous Al2O3 Ceramics Using Thermoplastic Polymer

열가소성 고분자를 이용한 다공질 알루미나의 제조

  • 이상진 (한국기계연구원 세라믹재료그룹) ;
  • 김해두 (한국기계연구원 세라믹재료그룹)
  • Published : 2004.07.01
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Abstract

Porous alumina ceramics with aligned plate-shaped pores were fabricated by using thermoplastic microsphere in order to show the anisotropy in thermal conductivity. The mixed powder of alumina and microsphere was pressed under 15 MPa till 20$0^{\circ}C$ to deform polymer into platelet-shape and sintered at 1,00$0^{\circ}C$ for 1 h. The sintered specimen with 10 wt% microsphere has 45.3% porosity and the bending strength of 44 MPa. The microstructural investigation confirmed the pore structure of platelet-shape, the thermal conductivities for vertical and parallel directions are 3.803 W/mK and 7.818 W/mK, respectively, the ratio between two directions exceeds 2.

기공크기와 형태를 제어하여 열전도도 이방성을 나타내기 위해 판상의 기공이 배향된 다공질 알루미나 소결체의 제조방법을 연구하였다. 속이 가스로 차있는 열가소성 고분자 microsphere를 알루미나 분말과 혼합한 후 일축 가압 열변형 방법을 이용하여 15 MPa의 압력으로 가압한 상태에서 20$0^{\circ}C$까지 승온하여 microsphere를 판상으로 변형시킨 후, 1,00$0^{\circ}C$에서 1시간동안 소결하였다. Microsphere의 함량이 10wt%인 경우 45.3%의 기공율을 나타내었으며, 44 MPa의 꺾임강도 값을 나타내었다. 미세구조를 살펴본 결과 판상기공이 압축방향과 수직방향으로 배향되었으며, 열전도도를 측정한 결과 압축방향으로 3.803 W/mK, 측면방향으로는 7.818 W/mK로서 두 값의 비는 2 이상이었다.

Keywords

References

  1. Ceramist v.4 no.6 Development of High-Performance Porous Ceramic Membrane J.-G. Kim;H.-C. Shin;J.-H. Shim;W.-S. Cho;J.-H. Oh
  2. Porosity of Ceramics R. W. Rice
  3. Bull. Am. Ceram. Soc. v.76 no.10 Gelcasting Foams for Porous Ceramics P. Sepulveda
  4. J. Am. Ceram. Soc. v.68 no.7 Fabrication and Mechanical Properties of Lightweight Ceramics Produced by Sintering of Hollow Spheres D. J. Green https://doi.org/10.1111/j.1151-2916.1985.tb10153.x
  5. J. Am. Ceram. Soc. v.73 no.1 Processing and Properties of Cellular Silica Synthesized by Foaming Sol-gels T. Fujiu;G. L. Messing;W. Huebner https://doi.org/10.1111/j.1151-2916.1990.tb05095.x
  6. J. Kor. Asso. Crys. Growth v.12 no.1 Fabrication of Porous Clay Ceramics Using Surfactant Y.-J. Kim;O.-J. Bae
  7. U.S. Patent. US-4777153
  8. J. Am. Ceram. Soc. v.37 no.2 Thermal Conductivity : IX, Experimental Investigation of Effect of Porosity on Thermal Conductivity J. Francl;W. D. Kingery https://doi.org/10.1111/j.1551-2916.1954.tb20108.x
  9. J. Am. Ceram. Soc. v.82 no.7 Engineered Porosity via Tape Casting Lamination and the Percolation of Pyrolyzable Particulates S. F. Corbin;P. S. Apte https://doi.org/10.1111/j.1151-2916.1999.tb01988.x
  10. J. Am. Ceram. Soc. v.84 no.6 Fabrication of Porous Ceramics with Unidirectionally Aligned Continuous Pores G. Zhang;J. Yang;T. Ohji https://doi.org/10.1111/j.1151-2916.2001.tb00849.x
  11. J. Kor. Ceram. Soc. v.31 no.9 Fabrication of Porous Ceramics and Multi-Layered Ceramics Containing Porous Layers : I. Pore Structure H.-W. Lee;B.-G. Yoon;H. Song
  12. J. Kor. Ceram. Soc. v.31 no.11 Fabrication of Porous Ceramics and Multi-Layered Ceramics Containing Porous Layers : II. Heterogeneous Laminates H.-W. Lee;B.-G. Yoon;H. Song
  13. Handbook of Properties of Technical & Engineering Ceramics R. Morrell
  14. J. Am. Ceram. Soc. v.80 no.2 Strain Tolerant Porous Silicon Nitride T. Shigegaki;M. E. Brito;K. Hirao;M. Toriyama;S. Kanzaki https://doi.org/10.1111/j.1151-2916.1997.tb02856.x
  15. J. Am. Ceram. Soc. v.80 no.10 Effect of Porosity and Microstructure on the Strength of $Si_3N_4$ : Designed Microstructure for High Strength, High Thermal Shock Resistance, and Facile Machining C. Kawai;A. Yamakawa https://doi.org/10.1111/j.1151-2916.1997.tb03179.x