Paper Titles
Influence of Type of Cations on Intergranular Phase Crystallisation of SiAlON Ceramics
p.119
Silicon Nitride – Carbon Nanotube Composites
p.123
Particle -Reinforced SiAlONs for Cutting Tools
p.129
ZrO2-TiN Composites
p.135
Effect of Fibre Heat-Treatment on Nicalon SiC Fibre Reinforced β-SiAlON Matrix Composites
p.141
Corrosion Resistance of β-SiAlON-Based Ceramics Against Molten Steel
p.147
From Earth Minerals to Nitrides
p.151
The Growth and the Reaction Mechanism of Si3N4 Powder from Silica
p.157
Carbothermal Reduction and Nitridation of Quartz Mineral for the Production of Alpha Silicon Nitride Powders
p.163

Effect of Fibre Heat-Treatment on Nicalon SiC Fibre Reinforced β-SiAlON Matrix Composites

Article Preview

Abstract:

Nicalon SiC fibre tows have excellent properties for ceramic matrix reinforcement but residual oxygen within the fibres degrades fibre properties when these are incorporated into ceramic matrices at elevated temperatures. β-SiAlON ceramics also have excellent mechanical and physical properties, especially fracture toughness. However, sintering of β-SiAlON is generally carried out at 1650-1750°C, considerably higher than the temperatures above which fibre degradation occurs (>1200°C). In the present study, the refractoriness and strength of Nicalon fibres were improved by high pressure CO heat treatment, and densification temperatures of β-SiAlON were lowered by using different kinds of sintering additives. Heat-treatment of the fibres under 45 bar CO pressure at 1500-1650°C led to an increase in fibre strength and to the formation of a thin carbon layer on the surface of the fibres. These improvements in the Nicalon SiC fibres allowed them to be incorporated successfully into β-SiAlON matrices. The as-received and heat-treated fibres were infiltrated with β-SiAlON starting powder mixes and hot-pressed with low temperature sintering additives at 1600-1700°C for 30 min. Bending strength and fracture toughness measurements showed that samples containing heat-treated fibres provided a significant strength and fracture toughness increase compared with similar samples prepared using as-received fibres, and massive pull-out was observed because of the weak interface resulting from the surface carbon coating on the fibres.

You might also be interested in these eBooks
Nitrides and Oxynitrides III View Preview

Info:

Periodical:

Materials Science Forum (Volume 554)

Pages:

141-146

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.554.141

Citation:

Cite this paper

Online since:

August 2007

Authors:

Adem Demir, Derek P. Thompson

Keywords:

Ceramic Matrix Composite (CMC), CO Heat Treatment, SiC Fiber, ß-SiAlON

Export:

RIS, BibTeX

Price:

Permissions CCC:

Request Permissions

Permissions PLS:

Request Permissions

Сopyright:

© 2007 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

References

[1] K.K. Chawla: Ceramic Matrix Composites (second ed), Kluwer, Academic Press, Norvell (MA), Dordrecht, The Netherlands (2003).

Google Scholar

[2] H. Ohnabe, S. Masaki, M. Onozuka, K. Miyahara and T. Sasa: Composites Part A: Appl Sci Manuf 30 (4) (1999), pp.489-496.

DOI: 10.1016/s1359-835x(98)00139-0

Google Scholar

[3] H. Kaya: Comput Sci Technol 59 (6) (1999), pp.861-872.

Google Scholar

[4] K. Ueno and T. Inoue: Ceram. Int. 23 (2) (1997), pp.165-170.

Google Scholar

[5] S. Kitaoka, N. Kawashima, T. Suzuki, Y. Sugita, N. Shinohara and T. Higuchi: J. Am. Ceram. Soc. 84 (9) (2001), p.1945-(1951).

Google Scholar

[6] N. Chandra and H. Ghonem: Composites Part A: Appl. Sci. Manuf. 32 (3-4) (2001), pp.575-584.

Google Scholar

[7] T. Mah, N.L. Hetch, D.E. McCullen, J.R. Hoinigman, H.M. Kim, A.P. Katz and H.A. Lipsitt: J. Mater. Sci. 18 (1984), pp.119-201.

Google Scholar

[8] Coustumer, P.L.: J. Eur. Ceram. Soc. (11) (1993), pp.139-49.

Google Scholar

[9] A. Demir and D.P. Thompson: J. Mater. Sci. 36 (2001), pp.2931-2935.

Google Scholar