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Microstructures of SiO2 Scales Formed on MoSi2

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Abstract:

The microstructures of oxide scales formed on MoSi2 at medium-high temperatures in air were observed by TEM. Based on the observation, relationships between oxidation temperature and formation of MoO3 and crystallization of amorphous SiO2 scales were investigated. At 1273 K and 1373 K, the oxide scales had a structure consisting of amorphous SiO2 with small amounts of fine MoO3 particles. The oxide scales at 1573 K and 1773 K had a structure consisting of amorphous and crystalline SiO2. Growth rate of the oxide scale formed at 1773 K appreciably increased due to crystallization of amorphous SiO2. It was thought that the increase in the oxidation rate at 1773 K was caused by a change in the diffusion mechanism from O2 diffusion to lattice diffusion of O2- through SiO2. In addition, the diffusion coefficient of oxygen was estimated from the growth rate of SiO2 scale.

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Periodical:

Materials Science Forum (Volumes 522-523)

Pages:

595-602

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.522-523.595

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Online since:

August 2006

Authors:

Kazuya Kurokawa, Daichi Goto, Jyunichi Kuchino, Akira Yamauchi, Tamaki Shibayama, Heishichiro Takahashi

Keywords:

Microstructure of Oxide Scale, MoSi2, Oxidation, TEM

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© 2006 Trans Tech Publications Ltd. All Rights Reserved

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References

[1] P. J. Mescher: Metall. Trans. Vol. 23A (1992), p.1763.

Google Scholar

[2] K. Kurokawa, H. Hozumi, I. Saeki and H. Takahashi: Mater. Sci. Eng. Vol. A261 (1992), p.292.

Google Scholar

[3] D. A. Berztiss, R. R. Cerchiara, E. A. Gulbransen, F. S. Pettit and G. H. Meier: Maters. Sci. Eng. Vol. A155 (1992), p.165.

Google Scholar

[4] T. Mochizuki and M. Kawanishi: J. Electrochem. Soc. Vol. 127 (1980), p.1128.

Google Scholar

[5] G. H. Meier: Oxidation of Intermetallics (ed. by H. J. Grabke and M. Schütze, WILEY-VCH, Germany 1997), p.15.

Google Scholar

[6] K. Kurokawa, T. Matsuoka and H. Takahashi: Mater. Sci. Forum Vol. 251-254 (1997), p.885.

Google Scholar

[7] K. Kurokawa, J. Kuchino, H. Hara, H. Takahashi, T. Shibayama and H. Takahashi: Mater. High Temp. Vol. 18 (2001), p.357.

Google Scholar

[8] K. Kurokawa, H. Hara, H. Takahashi, and H. Takahashi: Vacuum Vol. 65(2002), p.497.

Google Scholar

[9] K. Kurokawa, H. Hara, A. Shibayama, and H. Takahashi: High Temperature Materials, ed. S. C. Singhal, Electrochem. Soc., (2002), p.240.

Google Scholar

[10] W. G. Kingery, H. K. Bowen and D. R. Uhlman: Introduction to Ceramics (John Willy & Sons, New York 1975), p.240.

Google Scholar