摘要 |
<p>The invention concerns a friction element produced in a composite material comprising a carbon fiber reinforcement and a matrix which, at least in the proximity of each or the friction surface, comprises: a first phase containing pyrocarbon obtained by chemical infiltration in vapour phase, in the proximity of the reinforcing fibers, a second carbon or ceramic refractory phase obtained at least partly by pyrolysis from a liquid precursor, and a silicon carbide phase obtained for example by siliconizing. Preferably, at least in the proximity of each or the friction surface, the composite material is constituted, in volume, of at least: 15 % to 35 % of carbon fibers, 10 % to 55 % of the first matrix phase containing pyrocarbon, 2 % to 30 % of the second matrix phase in refractory material, and 10 % to 35 % of silicon carbide. The invention is particularly useful for railway braking and for motor vehicles.</p> |