Add to ORKGA wide range of carbon/carbon (C/C) composites with modulated interface was obtained by treating the carbon surface (ex-polyacrylonitrile type) before gaseous densification. The production processes are based on the impregnation of the fibrous preforms by liquid means and / or the carboreduction of oxides deposited on the fibers. The control of carboreduction required an in-depth study of the physico-chemical phenomena involved. At the interface level, changes in the microstructure (presence of submicron particles of various nature, fiber roughness, chemical bridging) result in a fiber/matrix bond of variable strength. The mechanical properties of the interfaces could be measured in shear and aperture mode, using specific techniques develop...