Method for producing a composite part containing a ceramic matrix
A process for manufacturing a composite material part including a particulate reinforcement densified by a ceramic matrix, the process including: formation of a blank of the part to be manufactured by shaping a mixture including a binder, first ceramic or carbon particles intended to form the particulate reinforcement of the part and second ceramic or carbon particles distinct from the first particles, removal or pyrolysis of the binder present in the blank to obtain a porous preform of the part to be manufactured, and infiltration of the porosity of the preform by a molten composition including a metal in order to obtain the part.
1. A process for manufacturing a composite material part comprising a particulate reinforcement densified by a ceramic matrix, the process comprising:
forming a blank of the part to be manufactured by shaping a mixture comprising a binder, first ceramic or carbon particles intended to form the particulate reinforcement of the part and second ceramic or carbon particles distinct from the first particles,
removing or pyrolyzing the binder present in the blank to obtain a porous preform of the part, and
infiltrating the porosity of the preform by a molten composition comprising a metal in order to obtain the part,
wherein the process further comprises, before the infiltrating, a step of hot isostatic compression of the porous preform obtained after removal or pyrolysis of the binder.
2. The process as claimed in claim 1 , wherein the molten composition comprises silicon.
3. The process as claimed in claim 1 , wherein the first particles are short fibers having a length comprised between 50 μm and 5000 μm.
4. The process as claimed in claim 3 , wherein the short fibers have a length comprised between 100 μm and 300 μm.
5. The process as claimed in claim 1 , wherein the first particles are grains.
6. The process as claimed in claim 1 , wherein the median elementary volume of the first particles is greater than or equal to the median elementary volume of the second particles.
7. The process as claimed in claim 1 , wherein shaping the mixture comprises injecting the mixture into a mold.
8. The process as claimed in claim 7 , wherein a liquid medium comprising the mixture is injected into the mold, the mold being equipped with a filtration device for the liquid medium, and the step of forming the blank further comprises the filtration of the liquid medium by the filtration device.
9. The process as claimed in claim 1 , wherein shaping the mixture comprises the application of pressure to the mixture.
10. The process as claimed in claim 9 , wherein shaping the mixture comprises cold isostatic compression of the mixture into a mold.
11. The process as claimed in claim 1 , wherein the first particles are silicon carbide.
12. The process as claimed in claim 1 , wherein the first particles are coated with an interphase.
13. The process as claimed in claim 1 , wherein the second ceramic particles comprise a material selected from the following: SiC, MoSi 2 , TiSi 2 , CoSi 2 , ZrSi 2 , ZrB 2 , HfB 2 , TiB 2 , and a mixture thereof.
14. The process as claimed in claim 1 , wherein the volume content of first particles in the part is comprised between 10% and 70% and/or wherein the volume content of second particles in the part is comprised between 30% and 90%.
15. The process as claimed in claim 1 , wherein the part is a part for use in an aeronautical turbomachine.
16. The process as claimed in claim 1 , wherein the porous preform has a porosity of at least 30% before the step of hot isostatic compression.
17. The process as claimed in claim 1 , wherein the step of hot isostatic compression is carried out to reduce a porosity of the porous preform, before the infiltrating, at least by a factor 2.