Paper number 163

EFFECT OF NITRIDATION ON PROPERTIES OF SIC MONOFILAMENT

SHI Nanlin¹, ², GUO Yanfen², Z X Guo¹

1Department of Materials, Queen Mary & Westfield College, University of London,
Mile End Road, London E1 4NS, UK
2Institute of Metal Research, Chinese Academy of Sciences
72 Wenhua Road, Shenyang , 110015, P.R.China

Summary

Pre-nitradation of the TiBx coating surface of the Sigma SM1240 SiC monofilament can form more stable compounds at the surface and obstruct the release of boron atoms into the Ti-based alloy matrix. The effect of nitridation on the tensile strength of the filament was investigated in this work. Nitridation could degrade the tensile strength of the SiC filament if the treating temperature and time are not optimized. The chemical reaction between the W core and SiC and the modification of filament microstructure during the nitridation are responsible for the degradation in strength . The strength can be maintained by further optimization of the treating temperature and time. Therefore, stabilizing the surface of TiBx coating and hence the interface of the SiCf/Ti composite by the nitridation of the SiC filament is a feasible technique for practical applications.

Keywords

SiC monofilament, Surface Coating, Nitridation, Tensile Strength.