Method for manufacturing a part of SiC/SiC composite material

A method for manufacturing a part of SiC/SiC composite material comprising:

• production of a fibrous preform from silicon carbide fibers;
• deposition of an interphase on the fibers of the fibrous preform;
• a first densification step comprising a formation of a first matrix phase by chemical vapor infiltration with a first SiC precursor comprising methyltrichlorosilane (MTS);
• a second densification step to obtain a partially densified preform comprising a formation of a second matrix phase by chemical vapor infiltration with a second SiC precursor different from said first precursor, the second precursor forming a SiC deposit comprising residual hydrogen and free silicon;
• a third densification step comprising an impregnation of the fibrous preform with an impregnation composition containing at least silicon so as to obtain a part made of SiC/SiC composite material, wherein the method further comprises comprising, after the second densification step and before the third densification step, a step of heat treating the partially densified preform at a temperature below a melting temperature of an infiltration composition.

A method for manufacturing a part of SiC/SiC composite material comprising:

• production of a fibrous preform from silicon carbide fibers;
• deposition of an interphase on the fibers of the fibrous preform;
• a first densification step comprising a formation of a first matrix phase by chemical vapor infiltration with a first SiC precursor comprising methyltrichlorosilane (MTS):
• a second densification step to obtain a partially densified preform comprising a formation of a second matrix phase by chemical vapor infiltration with a second SiC precursor different from said first precursor, the second precursor forming a SiC deposit comprising residual hydrogen and free silicon;
• a third densification step comprising an impregnation of the fibrous preform with an impregnation composition containing at least silicon so as to obtain a part made of SiC/SiC composite material;
• wherein the method further comprises comprising, after the second densification step and before the third densification step, machining a surface of the partially densified preform so as to reopen a porosity of the preform.

A method for manufacturing a part of SiC/SiC composite material comprising:

• production of a fibrous preform from silicon carbide fibers;
• deposition of an interphase on the fibers of the fibrous preform;
• a first densification step comprising a formation of a first matrix phase by chemical vapor infiltration with a first SiC precursor comprising methyltrichlorosilane MTS);
• a second densification step comprising a formation of a second matrix phase by chemical vapor infiltration with a second SiC precursor different from said first precursor, the second precursor forming a SiC deposit comprising residual hydrogen and free silicon;
• a third densification step comprising an impregnation of the fibrous preform with an impregnation composition containing at least silicon so as to obtain a part made of SiC/SiC composite material,
• wherein the method further comprises, between the first and second densification steps, a deposition on the first matrix phase of an interphase of boron nitride or pyrocarbon.

A method for manufacturing a part of SiC/SiC composite material comprising:

• production of a fibrous preform from silicon carbide fibers;
• deposition of an interphase on the fibers of the fibrous preform;
• a first densification step comprising a formation of a first matrix phase by chemical vapor infiltration with a first SiC precursor comprising methyltrichlorosilane (MTS);
• a second densification step comprising a formation of a second matrix phase by chemical vapor infiltration with a second SiC precursor different from said first precursor, the second precursor forming a SiC deposit comprising residual hydrogen and free silicon;
• a third densification step comprising an impregnation of the fibrous preform with an impregnation composition containing at least silicon so as to obtain a part made of SiC/SiC composite material,
• wherein the second densification step is carried out with a third matrix precursor combined with the second matrix precursor, the third matrix precursor being capable of introducing hydrogen into the second matrix phase.