Microstructure and Mechanical Properties of Silica Xerogels Doped with SiC Whisker and Short Carbon Fiber

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Silica xerogels were prepared by sol-gel process and non-supercritical drying. Two kinds of reinforcements, SiC whisker and short carbon fiber (CF), were chosen to control the shrinkage during drying process and improve the mechanical properties of xerogels. Microstructure and mechanical properties of samples were examined. It was found that the addition of SiC whisker could greatly improve the elastic modulus of silica xerogels, while short CF could prominently decrease the volume shrinkage ratio but could not improve the elastic modulus. Analysis showed that the difference between the two reinforcement mechanisms was caused by the interface and the size of the doped fiber and whisker.

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Periodical:

Key Engineering Materials (Volumes 336-338)

Edited by:

Wei Pan and Jianghong Gong

Pages:

2104-2106

DOI:

10.4028/www.scientific.net/KEM.336-338.2104

Citation:

L. L. Yang et al., "Microstructure and Mechanical Properties of Silica Xerogels Doped with SiC Whisker and Short Carbon Fiber", Key Engineering Materials, Vols. 336-338, pp. 2104-2106, 2007

Online since:

April 2007

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$35.00

[1] J. Hayashi, Y. Watada, K. Muroyama: Materials Letters Vol. 50 (2001), p.87.

[2] M.A. Einarsrud, E. Nilsen: J. Non-Cryst. Solids Vol. 226 (1998), p.122.

[3] J. Wang, J. Kuhn, X. Lu: J. Non-Cryst. Solids Vol. 186 (1995), pp.296-299.

[4] Z.S. Deng, J. Wang, A. Wu, J. Shen, B. Zhou: J. Non-Cryst. Solids Vol. 225 (1998), p.101.

[5] R. Petricevic, M. Glora, J. Fricke: J. Carbon Vol. 39 (2001), pp.857-859. Table 2 Properties of SiO2-SiC xerogels with different SiC weight ratio Whisker ratio [wt. %] Density [g/cm3] Volume shrinkage ratio [%] Modulus [MPa] 0 0. 301 48 16. 5.

5 0. 392 46 45. 6.

[1] 0 0. 398 43 46. 7.

[1] 5 0. 385 41 47. 5.

[2] 0 0. 385 38 48. 5.

0 0. 1 0. 2 0. 3 0. 4 0. 5 0. 6.

0.

1.

2.

3.

4.

5.

6.

7 Comprssion Stress (MPa) Strain.

00 0. 05 0. 10 0. 15 0. 20 0. 25 0. 30 0 2 4 6 8 10 12 14 16 18 Comprssion stress (MPa) Strain Fig. 3 Compression stress-strain plots of SiO2-CF xerogels. (a, left) and SiO2-CF xerogels (b, right).

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