Method for smoothing the surface of a part made from a CMC material
View Patent ↗A method of smoothing the surface of a ceramic matrix composite part presenting a surface that is undulating and rough. The method includes forming a ceramic coating on the surface of the part, the coating being made by applying a liquid composition on the surface of the part, the composition containing a ceramic-precursor polymer and a factory solid filler, curing the polymer, and transforming the cured polymer into ceramic by heat treatment. The method further includes impregnating the ceramic coating with a liquid metallic composition.
1. A part made of thermostructural composite material comprising refractory fiber reinforcement densified by a ceramic matrix, the part also being provided with a ceramic coating comprising a ceramic phase and grains of a solid filler in powder form, the part further comprising a layer of metallic composition formed on an accessible surface of said ceramic coating, the metallic composition binding together the grains of the solid filler and/or particles of the ceramic coating and the layer of metallic composition forming on the accessible surface of the ceramic coating a layer that presents a smooth surface state, the metallic composition being retained in the ceramic coating and the metallic composition being made of a material that is different from that of the rains of the solid filler.
2. A part according to claim 1 , constituting a gas turbine blade.
3. A turbomachine fitted with a blade according to claim 2 .
4. A part according to claim 1 , wherein the part comprises carbon fiber reinforcement densified by a matrix of silicon carbide.
5. A part according to claim 1 , wherein the part comprises carbon fiber reinforcement densified by a silicon-based matrix.
6. A part according to claim 1 , wherein the part comprises silicon carbide fiber reinforcement densified by a silicon carbide matrix, and wherein the metallic composition is based on silicon-germanium alloy.
7. A part according to claim 1 , wherein the part comprises silicon carbide fiber reinforcement densified by a silicon carbide matrix, and wherein the metallic composition is based on silicon-nickel alloy.
8. A part comprising:
a densified component made of a thermostructural composite material consisting of a refractory fiber reinforcement densified by a ceramic matrix, and
a ceramic coating arranged on an external surface of the densified component, the ceramic coating comprising a ceramic phase and grains of a solid filler in powder form, wherein a layer of metallic composition is formed on an accessible surface of said ceramic coating, the metallic composition binding together the grains of the solid filler and/or particles of the ceramic coating and the layer of metallic composition forming on the accessible surface of the ceramic coating a layer that presents a smooth surface state, the metallic composition being made of a material that is different from that of the grains of the solid filler.
9. The part according to claim 8 , wherein the metallic composition is retained in the ceramic coating.
10. The part according to claim 8 , wherein the part constitutes a gas turbine blade.
11. A part made of thermostructural composite material comprising refractory fiber reinforcement densified by a ceramic matrix, the part also being provided with a ceramic coating comprising a ceramic phase and grains of a solid filler, the part further comprising a layer of metallic composition formed on an accessible surface of said ceramic coating, the metallic composition binding together the grains of the solid filler and/or particles of the ceramic coating and the layer of metallic composition forming on the accessible surface of the ceramic coating a layer that presents a smooth surface state, the metallic composition being retained in the ceramic coating, wherein the metallic composition is based on silicon-germanium alloy or on silicon-nickel alloy.