Structural and textural analyses of SiC-based and carbon CVD coatings by Raman Microspectroscopy

The polarization properties of Raman scattering have been utilized for the texture analysis of SiC-based and carbon coatings processed by CVD. A polarized Raman scattering analysis of the optical phonons was conducted to characterize the structural state of the SiC and aromatic carbon phases and appraise the possible preferential orientation of the SiC crystallites or the graphene layers in the coatings.This approach was applied through the Raman mappings of SiC-based and pyrocarbon coating cross-sections, for various structural materials such as CVD-monofilaments and C/C composites. The structural and textural properties of SiC and pyrocarbon coatings have been correlated with the CVD/CVI processes involved.