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Enhancement of thermal conductivity in ceramics obtained from a combustion synthesized AlN powder by microwave sintering and reheating

Published online by Cambridge University Press:  31 January 2011

Shyan-Lung Chung*
Affiliation:
Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan 70101, Republic of China
Cheng-Yu Hsieh
Affiliation:
Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan 70101, Republic of China
Chih-Wei Chang
Affiliation:
Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan 70101, Republic of China
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

A combustion-synthesized AlN powder was investigated for use as a starting material in obtaining a high thermal conductivity AlN by microwave sintering followed by microwave reheating under a reducing atmosphere. Microwave sintering was found to proceed very quickly so that a density of 99.5% of theoretical with a thermal conductivity of 165 W/mK was achieved after sintering at 1900 °C for 5 min. The thermal conductivity could be improved by prolonging the soaking time, which is attributed to decreases in both oxygen content and secondary phases by evaporation and sublimation of the secondary phases. The reducing atmosphere was created by adding carbon particles to the AlN packing powder surrounding the specimen. The thermal conductivity could be significantly improved by microwave reheating of the sintered specimen under the reducing atmosphere. This is considered to be due to enhanced removal of the secondary phases by the reducing atmosphere. Sintering under the reducing atmosphere was found to retard densification because of the earlier removal of the secondary phases, thus resulting in a poor densification and a low thermal conductivity.

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Articles
Copyright
Copyright © Materials Research Society 2008

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References

REFERENCES

1Slack, G.A., Tanzilli, R.A., Pohl, R.O., Vandersande, J.W.: The intrinsic thermal conductivity of AlN. J. Phys. Chem. Solids 48(7), 641 1987CrossRefGoogle Scholar
2Mroz, T.J. Jr.: Annual materials review: Aluminum nitride. Am. Ceram. Soc. Bull. 71, 782 1992Google Scholar
3Sheppard, L.M.: Aluminum nitride: A versatile but challenging material. Am. Ceram. Soc. Bull. 69, 1801 1990Google Scholar
4Bachilard, B., Joubert, P.: Aluminum nitride by carbothermal nitridation. Mater. Sci. Eng., A 109, 247 1989Google Scholar
5Merzhanov, A.G., Borovinskaya, I.P.: New class of combustion processes. Combust. Sci. Technol. 10, 195 1975Google Scholar
6Lin, C.N., Chung, S.L.: Combustion synthesis of aluminum nitride powder using additives. J. Mater. Res. 16(8), 2200 2001CrossRefGoogle Scholar
7Lin, C.N., Chung, S.L.: A combustion synthesis method for synthesis of aluminum nitride powder using aluminum container. J. Mater. Res. 16(12), 3518 2001CrossRefGoogle Scholar
8Lin, C.N., Chung, S.L.: Combustion synthesis method for synthesis of aluminum nitride powder using aluminum containers (II). J. Mater. Res. 19(10), 3037 2004CrossRefGoogle Scholar
9Hsieh, C.Y., Chung, S.L.: High thermal conductivity epoxy molding compound filled with a combustion synthesized AlN powder. J. Appl. Polym. Sci. 102, 4737 2006CrossRefGoogle Scholar
10Hsieh, C.Y., Lin, C.N., Chung, S.L., Cheng, J., Agrawal, D.K.: Microwave sintering of AlN powder synthesized by a SHS method. J. Eur. Ceram. Soc. 27, 343 2007Google Scholar
11Jackson, T.B., Vikar, A.V., More, K.L., Dinwiddie, R.B.: High-thermal-conductivity aluminum nitride ceramics: The effect of thermodynamic, kinetic, and microstructural factors. J. Am. Ceram. Soc. 6, 1421 1997Google Scholar
12Nakano, H., Watari, K., Hayashi, H., Urabe, K.: Microstructure characterization of high-thermal-conductivity aluminum nitride ceramic. J. Am Ceram. Soc. 12, 3093 2002Google Scholar
13Nakano, H., Watari, K., Urabe, K.: Grain boundary phase in AlN ceramics fired under reducing N2 atmosphere with carbon. J. Eur. Ceram. Soc. 23, 1761 2003CrossRefGoogle Scholar
14Cheng, J., Agrawal, D., Roy, R., Jayan, P.S.: Continuous microwave sintering of alumina abrasive grits. J. Mater. Proc. Technol. 108, 26 2000Google Scholar
15Katz, J.D., Blake, R.D.: Microwave sintering of multiple alumina and composite components. Am. Ceram. Soc. Bull. 70, 1304 1991Google Scholar
16Wang, J., Binner, J., Vaidhyanathan, B., Joomun, N., Kliner, J., Dimitrakis, G., Cross, T.E.: Evidence for the microwave effect during hybrid sintering. J. Am. Ceram. Soc. 6, 1977 2006Google Scholar
17Cheng, J., Agrawal, D., Zhang, Y., Roy, R.: Development of translucent aluminum nitride (AlN) using microwave sintering process. J. Electroceram. 9, 67 2002Google Scholar
18Xu, G.F., Olorunyolemi, T., Wilson, O.C., Lloyd, I.K., Carmel, Y.: Microwave sintering of high-density, high thermal conductivity AlN. J. Mater. Res. 17(11), 2837 2002Google Scholar
19Komeya, K., Inoue, H., Tsuge, A.: Effect of various additives on sintering of aluminum nitride. Yogyo-Kyokai-Shi. 6, 330 1981CrossRefGoogle Scholar
20Hundere, A.M., Einarsrud, M.: Effects of reduction of the Al-Y-O containing secondary phases during sintering of AlN with YF3 additions. J. Eur. Ceram. Soc. 16, 899 1996CrossRefGoogle Scholar
21Virkar, A.V., Jackson, T.B., Cutler, R.A.: Thermodynamic and kinetic effects of oxygen removal on the thermal conductivity of aluminum nitride. J. Am. Ceram. Soc. 72, 2031 1989CrossRefGoogle Scholar
22Watari, K., Nakano, H., Urabe, K., Ishizaki, K., Cao, S., Mori, K.: Thermal conductivity of AlN ceramic with a very low amount of grain boundary phase at 4 to 1000 K. J. Mater. Res. 17(11), 2940 2002CrossRefGoogle Scholar
23Kuramoto, N., Taniguchi, H., Numata, Y., Aso, I.: Sintering process of translucent AlN and effect of impurities on thermal conductivity of AlN ceramics. Yogyo-Kyokai-Shi. 93(9), 517 1985Google Scholar
24Terao, R., Tatami, J., Meguro, T., Komeya, K.: Fracture behavior of AlN ceramics with rare earth oxides. J. Eur. Ceram. Soc. 22, 1051 2002Google Scholar
25Bellosi, A., Esposito, L., Scafe, E., Fabbri, L.: The influence of microstructure on the thermal conductivity of aluminum nitride. J. Mater. Sci. 29, 5014 1994Google Scholar
26Brosnan, K.H., Messing, G.L., Agrawal, D.K.: Microwave sintering of alumina at 2.45 GHz. J. Am. Ceram. Soc. 86, 1307 2003CrossRefGoogle Scholar
27Yagi, T., Shinozaki, K., Kato, M., Sawada, Y., Mizutani, N.: Migration of grain boundary phase of AlN ceramics on joined sample of sintered and hot-pressed body. J. Ceram. Soc. Jpn. 98, 198 1990CrossRefGoogle Scholar
29Watari, K., Kawamoto, M., Ishizaki, K.: Sintering chemical reactions to increase thermal conductivity of aluminum nitride. J. Mater. Sci. 26, 4727 1991Google Scholar
30Yan, H., Cannon, W.R., Shanefield, D.J.: Evolution of carbon during burnout and sintering of tape-cast aluminum nitride. J. Am. Ceram. Soc. 1, 166 1993Google Scholar