Process for manufacturing a composite friction component
A process for manufacturing a friction component made of composite material, includes the densification of a fibrous preform of carbon yarns by a matrix including at least pyrocarbon and at least one ZrO x C y phase, where 1≤x≤2 and 0≤y≤1, the matrix being formed by chemical vapor infiltration at least from a first gaseous precursor of pyrocarbon and a second gaseous precursor including zirconium, the second precursor being an alcohol or a C 1 to C 6 polyalcohol modified by linking the oxygen atom of at least one alcohol function to a group of formula —Zr—R 3 , the substituents R being identical or different, and R being selected from: —H, C 1 to C 5 carbon chains and halogen atoms.
1. A process for manufacturing a friction component of composite material, comprising:
densification of a fibrous preform of carbon yarns by a matrix comprising at least pyrocarbon and at least one ZrO x C y phase, where 1≤x≤2 and 0≤y≤1, the matrix being formed by chemical vapor infiltration at least from a first gaseous precursor of pyrocarbon and a second gaseous precursor comprising zirconium, said second precursor being an alcohol or a C 1 to C 6 polyalcohol, which alcohol or a C 1 to C 6 polyalcohol is modified by linking the oxygen atom of at least one alcohol function to a group of formula —Zr—R 3 , the substituents R being identical or different, and R being selected from: —H, C 1 to C 5 carbon chains and halogen atoms.
2. The process claimed in claim 1 , wherein the densification comprises:
a first densification cycle in which a first pyrocarbon matrix phase is formed from the first precursor,
a second densification cycle, carried out after the first cycle, in which a second matrix phase comprising the ZrO x C y phase is formed at least from the second precursor, and
a third densification cycle, carried out after the second cycle, in which a third pyrocarbon matrix phase is formed from a third gaseous pyrocarbon precursor, identical or different from the first precursor.
3. The process claimed in claim 1 , wherein the densification comprises at least the formation of a co-deposition of the pyrocarbon phase and the ZrO x C y phase from a gaseous mixture of a gaseous pyrocarbon precursor and the second precursor.
4. The process as claimed in claim 1 , wherein R is selected from: —H, C 1 to C 3 carbon chains and halogen atoms.
5. The process as claimed in claim 1 , wherein at least one substituent R is a C 1 to C 5 or C 1 to C 3 carbon chain or a halogen atom.
6. The process as claimed in claim 1 , wherein the process further comprises a deoxygenation heat treatment of the ZrO x C y phase formed.
7. The process as claimed in claim 1 , wherein the ZrO x C y phase, optionally deoxygenated, is present, in the final component, in a mass content of between 0.5% and 25%.
8. The process claimed in claim 7 , wherein the ZrO x C y phase, optionally deoxygenated, is present, in the final component, in a mass content of between 2% and 10%.
9. The process as claimed in claim 1 , wherein the friction component is a brake disc.
10. The process as claimed in claim 1 , wherein the C 1 to C 6 polyalcohol is modified by linking the oxygen atom of each alcohol function to said group of formula —Zr—R 3 .