本研究使用2.0與3.5μm之堇青石(熟料)粉末，分別與高嶺土、滑石及氧化鋁均勻混合作為原料配方，經熱處理得到堇青石陶瓷體。觀察重點：添加不同粒徑的熟料，對合成之堇青石陶瓷體其內部產生之孔隙特性有無差異，此孔隙差異對陶瓷體熱膨脹係數產生的影響。
將配方粉末以球磨混合均勻並烘乾、過篩，經單軸加壓成型得到生胚，經燒結得到堇青石陶瓷體。藉由控制生胚密度、熱處理溫度、及持溫時間，製作不同孔隙率的陶瓷體，作為觀察樣品。
添加50wt%粒徑2.0及3.5μm熟料，所製作的堇青石陶瓷體，都可具有相當比例(>60%)之α相堇青石，極少量富鋁紅柱石。由SEM觀察製作的堇青石陶瓷體內部顯微結構，兩組陶瓷體內部孔隙形貌相同，存在兩種孔隙(1)均勻分佈的小孔隙孔徑，0.1~10μm；(2)堇青石熟料周邊產生的大孔隙，10~100μm。堇青石陶瓷體，隨著孔隙率增加，α-堇青石含量減少，熱膨脹係數亦增加。而細粒徑熟料製作的堇青石陶瓷體此現象更明顯。以兩種粒徑熟料粉末配方製作堇青石陶瓷體，若能具有越多α相堇青石(>60%)，殘留雜相越少(<全組成10%)，孔隙率25~35%，小孔隙(0.1~10μm)佔整體孔隙體積越多(>70%)，則可得到低熱膨脹係數( <1.15x10-6 mm/mm℃)的堇青石陶瓷體。

In this research, cordierite powders (seeds) of 3.5 and 2.0μm in diame-ter were mixed with powders of talc, alumina, and kaolinite used as raw material.The mixtures were then sintered to form cordierite ceramics. It attempts to relate the porosity formed with the thermal expansion coeffi-cient of the sintered cordierite ceramics result from the difference in size of seeds.
Mixed starting materials were treated by ball-milling, sieving, and drying. Using uniaxial compression then employed to obtain the green-body with different porosity followed by using heating conditions to get sintered cordierite ceramics. The sintered cordierite ceramics examined by X-ray diffraction (XRD) to observe the crystalline phase. The thermal expansion coefficient was obtained by a dilatometer. A mercury penetrat-ing porometer was adopted to analyze the porosity.
Microstructures were observed by SEM. There are two kinds of pore present in the cordierite ceramics (1) Small pore (0.1 ~ 10μm in pore di-ameter); (2) The meso-pore (10 ~100μm) around the seed particles. As the porosity of cordierite ceramics increased, the thermal expansion coef-ficient also increased being possibly due to lower % of α-cordierite pre-sent in the ceramics. If the ceramics have more α-cordierite (> 60%), less mullite (<10% of all components), porosity 25~35%, pore volume of small pore / total pore >70%, then the sintered cordierite ceramics could get lower thermal expansion coefficient (<1.15x10-6 mm / mm℃)

[1] A. Miyashiro, “Cordierite-Indialite Relations,” American Journal of Science, vol. 255, no. 1, pp. 43–62, Jan. 1957.
[2] C. B. Carter and M. G. Norton, Ceramic Materials: Science and Engineering. Springer, 2007, p. 129.
[3] M. D. Glendenning and W. E. Lee, “Microstructural Development on Crystallizing Hot-Pressed Pellets of Cordierite Melt-derived Glass Containing B2O3 and P2O5,” Journal of the American Ceramic Society, vol. 79, no. 3, pp. 705–713, Apr. 2005.
[4] H. Misran, S. Begum, and A. Aminuddin, “Developing of Honeycomb Shaped Cordierite Ceramic from Indigenous Raw Materials and its Characterization,” Advanced Materials Research, vol. 264–265, pp. 597–601, Jul. 2011.
[5] M.E. Tyrrel, G.V. Gibbs, H.R. Shell, Synthetic Cordierite. Washington: U.S. Goverment Printing Office, 1961.
[6] R. Goren, H. Gocmez, and C. Ozgur, “Synthesis of Cordierite Powder from Talc, Diatomite and Alumina,” Ceramics International, vol. 32, no. 4, pp. 407–409, Jan. 2006.
[7] T. Ogiwara, Y. Noda, K. Shoji, and O. Kimura, “Solid State Synthesis and its Characterization of High Density Cordierite Ceramics using Fine Oxide Powders,” Journal of the Ceramic Society of Japan, vol. 118, no. 1375, pp. 246–249, 2010.
[8] F. A. Hummel and H. W. Reid, “Thermal Expansion of Some Glasses in the System MgO-Al2O3-SiO2,” Journal of the American Ceramic Society, vol. 34, no. 10, pp. 319–321, Oct. 1951.
[9] R. Goren, C. Ozgur, and H. Gocmez, “The Preparation of Cordierite from Talc, Fly Ash, Fused Silica and Alumina Mixtures,” Ceramics International, vol. 32, no. 1, pp. 53–56, Jan. 2006.
[10] M. F. Hochella and G. E. Brown, “Structural Mechanisms of Anomalous Thermal Expansion of Cordierite-Beryl and Other Framework Silicates,” Journal of the American Ceramic Society, vol. 69, no. 1, pp. 13–18, Jan. 1986.
[11] A. Putnis, An Introduction to Mineral Sciences. Cambridge University Press, 1992.
[12] J. Do Lee and J. L. Pentecost, “Properties of Flux-Grown Cordierite Single Crystals,” Journal of the American Ceramic Society, vol. 59, no. 3–4, pp. 183–183, Mar. 1976.
[13] M. E. Milberg and H. D. Blair, “Thermal Expansion of Cordierite,” Journal of the American Ceramic Society, vol. 60, no. 7–8, pp. 372–373, Jul. 1977.
[14] M. F. Hochella, G. E. Brown, F. K. Ross, G. V. Gibbs, “High- Temperature Crystal Chemistry of Hydrous Mg- and Fe- Cordierite,” American Mineralogist, vol. 64, pp. 337–351, 1979.
[15] P. Predecki, J. Haas, J. Faber, and R. L. Hitterman, “Structural Aspects of the Lattice Thermal Expansion of Hexagonal Cordierite,” Journal of the American Ceramic Society, vol. 70, no. 3, pp. 175–182, Mar. 1987.
[16] D. L. Evans, G. R. Fischer, J. E. Geiger, and F. W. Martin, “Thermal Expansions and Chemical Modifications of Cordierite,” Journal of the American Ceramic Society, vol. 63, no. 11–12, pp. 629–634, Nov. 1980.
[17] Lachman, Irwin M. Bagley, Rodney D. Lewis, Ronald M., “Thermal Expansion of Extruded Cordierite Ceramics,” American Ceramic Society bulletin, vol. 60, pp. 202–205, 1981.
[18] Y. Hirose, H. Doi, and O. Kamigaito, “Thermal Expansion of Hot-Pressed Cordierite Glass Ceramics,” Journal of Materials Science Letters, vol. 3, no. 2, pp. 153–155, Feb. 1984.
[19] A. Shyam, E. Lara-Curzio, A. Pandey, T. R. Watkins, and K. L. More, “The Thermal Expansion, Elastic and Fracture Properties of Porous Cordierite at Elevated Temperatures,” Journal of the American Ceramic Society, vol. 95, no. 5, pp. 1682–1691, May 2012.
[20] J. R. González-Velasco, R. Ferret, R. López-Fonseca, and M. A. Gutiérrez-Ortiz, “Influence of Particle Size Distribution of Precursor Oxides on the Synthesis of Cordierite by Solid-State Reaction,” Powder Technology, vol. 153, no. 1, pp. 34–42, May 2005.
[21] G. Bruno, A. M. Efremov, B. Clausen, A. M. Balagurov, V. N. Simkin, B. R. Wheaton, J. E. Webb, and D. W. Brown, “On The Stress-Free Lattice Expansion of Porous Cordierite,” Acta Materialia, vol. 58, no. 6, pp. 1994–2003, Apr. 2010.
[22] A. Shyam, E. Lara-Curzio, T. R. Watkins, and R. J. Parten, “Mechanical Characterization of Diesel Particulate Filter Substrates,” Journal of the American Ceramic Society, vol. 91, no. 6, pp. 1995–2001, Jun. 2008.
[23] Kazuhiko Koike, Tomohiko Nakanishi, Kojiro Tokuda, “Cordierite Honeycomb Structural Body and Method for its Production,” US5997984,07-Dec-1999.
[24] J. Banjuraizah, H. Mohamad, and Z. A. Ahmad, “Thermal Expansion Coefficient and Dielectric Properties of Non-Stoichiometric Cordierite Compositions with Excess MgO Mole Ratio Synthesized from Mainly Kaolin and Talc by the Glass Crystallization Method,” Journal of Alloys and Compounds, vol. 494, no. 1–2, pp. 256–260, Apr. 2010.
[25] Mussler B.H.,and Shafer M.W., “Preparation and Properties of Mullite-Cordierite Composites,” American Ceramic Society bulletin, vol. 63, no. 5, pp. 705–714, 1984.
[26] M. A. Camerucci, G. Urretavizcaya, M. S. Castro, and A. L. Cavalieri, “Electrical Properties and Thermal Expansion of Cordierite and Cordierite-Mullite Materials,” Journal of the European Ceramic Society, vol. 21, no. 16, pp. 2917–2923, Dec. 2001.
[27] J. Banjuraizah, H. Mohamad, and Z. A. Ahmad, “Effect of Excess MgO Mole Ratio in a Stoichiometric Cordierite (2MgO•2Al2O3•5SiO2) Composition on the Phase Transformation and Crystallization Behavior of Magnesium Aluminum Silicate Phases,” International Journal of Applied Ceramic Technology, vol. 8, no. 3, pp. 637–645, May 2011.
[28] Q. Zeng, K. Li, T. Fen-Chong, and P. Dangla, “Effect of Porosity on Thermal Expansion Coefficient of Cement Pastes and Mortars,” Construction and Building Materials, vol. 28, no. 1, pp. 468–475, 2012.
[29] Z. Shui, R. Zhang, W. Chen, and D. Xuan, “Effects of Mineral Admixtures on The Thermal Expansion Properties of Hardened Cement Paste,” Construction and Building Materials, vol. 24, no. 9, pp. 1761–1767, Sep. 2010.
[30] Zhu Kai, Yang Dao Yuan, Wu Juan, Zhang Rui, “Synthesis of Cordierite with Low Thermal Expansion Coefficient,” Advanced Material Research, vol. 105–106, pp. 802–804, 2010.
[31] 陳嘉庚, 段滿珍, 楊立荣, “影響合成堇青石材料熱膨脹係數的因素.” 耐火材料, pp. 201–204, 2007.
[32] S. Ghabezloo, “Effect of Porosity on the Thermal Expansion Coefficient: A discussion of the paper ‘Effects of Mineral Admixtures on the Thermal Expansion Properties of Hardened Cement Paste’ by Z.H. Shui, R. Zhang, W. Chen, D. Xuan, Constr. Build. Mater. 24 (9) (2010) 1,” Construction and Building Materials, vol. 24, no. 9, pp. 1796–1798, Sep. 2010.
[33] C. A. Fyfe, J. M. Thomas, J. Klinowski, and G. C. Gobbi, “Magic-Angle-Spinning NMR (MAS-NMR) Spectroscopy and the Structure of Zeolites,” Angewandte Chemie International Edition in English, vol. 22, no. 4, pp. 259–275, Apr. 1983.
[34] A. Putnis, E. Salje, S. A. T. Redfern, C. A. Fyfe, and H. Strobl, “Structural States of Mg-Cordierite I: Order Parameters from Synchrotron X-Ray and NMR Data,” Physics and Chemistry of Minerals, vol. 14, no. 5, pp. 446–454, 1987.
[35] A. Putnis, C. A. Fyfe, and G. C. Gobbi, “Al , Si Ordering on Cordierite Using ‘Magic Angle Spinning’ NMR,” Physics and Chemistry of Minerals, vol. 12, no. 4, pp. 211–216, Sep. 1985.