Effects of Impregnating and Heat Treatment on the Oxidation and Thermal Shock Properties of Pressureless Sintered SiC/Graphite Composites

Abstract:

SiC/0~20% graphite (volume fraction) composites were successfully fabricated by pressureless sintering at 1700 °C for 2 h in nitrogen atmosphere. The impregnating and heat treatment process for the samples with silica sol/phenolic impregnant was carried out at 1450 °C for 2 h in nitrogen atmosphere. The Vickers hardness, oxidation resistance and thermal shock property of the composites before and after treatment were tested, and the microstructure and phase composition were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The results shown that the Vickers hardness of SiC/20% graphite was increased from 3.35 GPa to 4.90 GPa by heat treatment, and the oxidation resistance and thermal shock property of the heat treated samples were also improved significantly. The SEM and XRD results revealed that the formation of new SiC particles by the reaction of silica sol and phenolic was the main reason for the mechanical properties improvements.

• Periodical: Materials Science Forum (Volume 724)
• Pages: 311-314
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.724.311
• Online since: June 2012
• Authors: Wan Li Yang, Zhong Qi Shi, Zhi Hao Jin, Guan Jun Qiao
• Keywords: Heat Treatment, Impregnating, Oxidation, SiC/Graphite, Thermal Shock

References

[1] X.D. Wang, G.J. Qiao and Z.H. Jin: J. Am. Ceram. Soc. Vol. 87 (2004), p.565.

[2] K. Suganuma, G. Sasaki, T. Fujita, M. Okumura and K. Niihara: J. Mater. Sci. Vol. 28 (1993), p.1175.

[3] N.P. Padture, C.J. Evans, H. Xu and B.R. Lawn: J. Am. Ceram. Soc. Vol. 78 (1995), p.215.

[4] H.W. Li, Q. Zhang, Z.H. Jin and G.J. Qiao: Mater. Sci. Forum. Vol. 620-622 (2009), p.403.

[5] H.Y. Jin, R. Zhou, G.J. Qiao, N.K. Gao, Z.R. Peng and J.Q. Gao: Mater. Sci. Forum. Vol. 620-622 (2009), p.513.

[6] H.W. Li, H.Y. Jin, Q. Zhang, J.F. Yang and Z.H. Jin: Scripta Mater. Vol. 63 (2010), p.1177.

[7] A. Herzog, M. Thunemann, U. Vogt and O. Beffort: J. Eur. Ceram. Soc. Vol. 25 (2005), p.187.

[8] Y.F. Li, P. Liu, X.D. Wang, J.F. Yang and G.J. Qiao: Scripta Mater. Vol. 63 (2010), p.185.

[9] W.L. Yang, Z.Q. Shi, H.W. Li, Z. Li, Z.H. Jin and G.J. Qiao: IOP Conf. Ser.: Mater. Sci. Eng. Vol. 18 (2011), p.1.

[10] Z.Q. Shi, J.P. Wang, G.J. Qiao and Z.H. Jin: Mater. Sci. Eng. A. Vol. 492 (2008), p.31.