Physical chemistry and mechanical imaging of ceramic-fibre-reinforced ceramic- or metal-matrix composites

Raman (micro)spectrometry allows the study of the non-metallic phases of ceramic- or metal-matrix composites at the micrometer scale. The three examples that are given concern a mullite-matrix composite reinforced by the Nippon Carbon NLM-202™ SiC fibre, an alumina-matrix composite reinforced by a Saphikon™ monocrystalline α-Al2O3 fibre and a Textron SCS-6™ fibre-reinforced Ti6242 matrix composite. Physical and chemical evolution of the SCS-6 fibre within the matrix is discussed. A comparison is made between residual thermal stresses estimated from the thermal expansion coefficients of the fibres and matrices and the values obtained from Raman wavenumber shifts.