Process for manufacturing a composite material part having a ceramic matrix

The invention relates to a method of manufacturing a composite material part comprising a fibrous reinforcement and a ceramic matrix present in the porosity of the fiber reinforcement, the method comprising at least the steps of: a) forming the fiber reinforcement by three-dimensional weaving ceramic son (step E1), the thus formed fibrous reinforcement having an interlock weave; b) forming a first matrix of ceramic phase in the pores of the fibrous reinforcement (step E4); c) introducing into the porosity of the fibrous reinforcement, after implementation of step b), a powder comprising ceramic particles and / or carbon particles (step E5); and d) infiltration of the fiber reinforcement obtained after implementation of step c) with a composition of infiltration in the molten state comprising at least silicon to form a second matrix ceramic phase in the pores of fiber reinforcement and thereby obtain the composite material part (step E6).