High temperature properties of SiC and diamond CVD-monofilaments

The chemical, structural and thermomechanical properties of SiC and diamond CVD-monofilaments have been investigated. Electron and Raman microprobe analyses showed graded radial atomic and phase distributions in the SiC filaments. Thermomechanical investigations (tensile/bending elastic modulus/creep tests) were carried out on single filaments and these properties were correlated with the physicochemical features. The thermal behaviour of the CVD-SiC filaments is strongly related to the nature and the amounts of intergranular secondary phases (free carbon or silicon). The strong covalent bonds and the microcrystalline state of the CVD-diamond filaments give rise to an outstanding thermal behaviour.