Process for the manufacture of a thermostructural composite material having a carbon interphase between its reinforcement fibers and its matrix

Abstract From the Canadian patent

The thermostructural composite material is produced by forming a fibrous preform made from refractory fibers coated with a sizing agent. The preform is densified by a refractory matrix in particular ceramic, while a carbon interphase is provided between the fibers and the matrix. The fibrous preform is made from refractory fibers coated with a sizing agent of the type that leaves behind a carbon residue upon thermal deccmposition. The carbon interphase is produced by the thermal degradation of the sizing agent, occurring for example after the preform is made. The sizing agent is chosen among phenolic, acrylic and cellulose resins, and in particular carboxymethylcellulose.