Thermal Conductivity of Ceramic Nanocomposites – The Phase Mixture Modeling Approach

Abstract:

In nanocrystalline materials the grain boundaries must be considered as regions of finite thickness with properties different from the crystalline bulk material present in the crystallite cores. Thus, dense (i.e. pore-free) single-phase nanocrystalline materials can be considered as quasi-twophase systems whose effective properties can be calculated when quantitative thickness information is available and the property value of the grain boundary phase can be reliably estimated. Similarly, dense two-phase nanocomposites may be considered as quasi-three-phase systems and their effective properties can be predicted using an analogous phase mixture modeling approach. In this contribution this is done for the thermal conductivity of alumina-zirconia nanocomposites. A twostage homogenization procedure is applied, consisting of a first step in which the alumina-zirconia composite is treated as a symmetric-cell material, and a second step in which the highly disordered grain boundary phase is treated as a matrix-phase, coating the crystallite cores. The individual averaging steps are discussed with respect to the two- and three-point bounds, and the resulting grain size dependence is compared with that of pure alumina and zirconia, and literature data.

• Periodical: Advances in Science and Technology (Volume 71)
• Pages: 68-73
• DOI: https://doi.org/10.4028/www.scientific.net/AST.71.68
• Online since: October 2010
• Authors: Willi Pabst, Jan Hostaša
• Keywords: Alumina, Beran Bound, Composite, Core-Shell Microstructure, Grain Boundary, Hashin-Shtrikman Bound, Nanocrystalline Ceramic, Phase Mixture Model, Sigmoidal Average, Symmetric-Cell Material, Thermal Conductivity (TC), Wiener Bound, Zirconia

References

[1] C.C. Koch (ed. ): Nanostructured Materials – Processing, Properties, and Applications. Second edition (William Andrew Publishing, Norwich / NY 2007).

[2] H.S. Nalwa (ed. ): Encyclopedia of Nanoscience and Nanotechnology (American Scientific Publishers, Valencia / CA 2004).

[3] S. Torquato: Random Heterogeneous Materials - Microstructure and Macroscopic Properties. (Springer, New York / NY 2002).

[4] M.B. Bush: Mater. Sci. Eng. A Vol. 161 (1993), p.127.

[5] G. Palumbo, S.J. Thorpe and K.T. Aust: Scripta Met. Mater. Vol. 24 (1990), p.1347.

[6] M.A. Khadar, V. Biju and A. Inoue: Mater. Res. Bull. Vol. 38 (2003), p.1341.

[7] R. Chaim and M. Hefetz: J. Mater. Sci. Vol. 39 (2004), p.3057.

[8] W. Pabst: pp.207-228 in T. -Y. Tseng and H.S. Nalwa (eds. ): Handbook of Nanoceramics and Their Based Nanodevices (American Scientifc Publishers, Stevenson Ranch / CA 2009).

[9] W. Pabst, E. Gregorová, J. Hostaša: pp.109-112 in M. Nakagawa, S. Luding (eds. ): Powders and Grains 2009 / AIP Conf. Proc. Vol. 1145 (American Institute of Physics, Melville / NY 2009).

[10] W. Pabst and E. Gregorová: Phase Mixture Models for the Properties of Nanoceramics (Nova Science Publishers, New York / NY 2010).

[11] E. Gregorová, W. Pabst: pp.33-40.

[12] W. Pabst and E. Gregorová: pp.77-137 in B.M. Caruta (ed. ): New Developments in Materials Science Research (Nova Science Publishers, New York / NY, 2007).

[13] W. Martienssen and H. Warlimont (eds. ): Springer Handbook of Condensed Matter and Materials Data (Springer, Berlin / Germany 2005).

DOI: 10.1007/3-540-30437-1

[14] N.P. Bansal and D. Zhu: Ceram. Intern. Vol. 31 (2005), p.911.

[15] S. Begand, T. Oberbach and W. Glien: Key Eng. Mater. Vol. 361-363 (2007), p.759.

[16] M. Iuga and F. Raether: J. Eur. Ceram. Soc. Vol. 27 (2007), p.511.

[17] T. Oberbach, S. Begand, W. Glien, C. Kaddick: Key Eng. Mater. Vol. 361-363 (2008), p.771.

DOI: 10.4028/www.scientific.net/kem.361-363.771

[18] J.O. Berghaus, J.G. Legoux, C. Moreau, F. Tarasi and T. Chráska: J. Thermal Spray Technol. Vol. 17 (2008), p.91.

DOI: 10.1007/s11666-007-9146-0