Received 25 January 2009; 

revised 22 May 2009; 

accepted 29 May 2009. 

Available online 11 July 2009.

Abstract

Precursor-derived Si–B–C–N ceramics are well known for their outstanding thermal stability up to 2000 °C. However, if they are integrated with long ceramic fiber fabrics, the thermal stability of the respective fiber–matrix composites decreases, and the associated thermomechanical properties worsen. A method of improving the thermal stability of a fiber-reinforced Si–B–C–N-based composite up to 1700 °C by the application of SiC filler particulates is reported. The mass loss of such composites is very low even after heating to 2100 °C. Remarkably, a pre-heat treatment of the SiC filler is essential in order to achieve the thermal stability of the ceramic matrix composites by removing surface SiO₂. The composite described here retained 96% of its room-temperature strength and possessed non-brittle fracture behavior after heating at 1700 °C for 10 h in Ar. The flexural creep deformation of the composite at 1400 °C was only 0.25% after 60 h under 100 MPa pressure.

Keywords: Slurry infiltration; Bending test; Creep test; Ceramic matrix composites; Si–B–C–N

Article Outline

1. Introduction

2. Experimental procedure

3. Results and discussion

3.1. Densification, microstructure and thermal mass stability

3.2. High-temperature properties

4. Conclusions

References

Corresponding author. Address: Engineering ceramic research group, Korea Institute of Materials Science (KIMS), 531 Changwondaero, Changwon, Gyeongnam 641-831, Republic of Korea. Tel.: +82 55 2803344; fax: +82 55 280 3392.
¹ Present address: H.C. Starck GmbH, Im Schleeke 78-91, D-38642 Goslar, Germany