A clutch system includes a first clutch member and a second clutch member for transmitting torque from a vehicle power generator. The first clutch member includes a first a first clutch element having a first surface and a first friction material disposed on said first surface. The second clutch member is configured to engage the first clutch plate and includes a second clutch element having a second surface and a second friction material disposed on the second surface. The first friction material is configured to be engaged with the second friction material during operation of the vehicle power generator.

A friction disk may comprise a first wear surface formed from a carbon fiber-carbon matrix composite material. A wear plug may be located in an opening defined by the carbon fiber-carbon matrix composite material. The wear plug may extend axially from the wear surface. The wear plug may comprise a rod or a particulate.

A method of producing a friction material. The method includes mixing silica containing filler particles and a liquid binder to form a binder-filler liquid mixture. The method also includes saturating a fibrous base material with the binder-filler liquid mixture to form a saturated fibrous base material. The method further includes curing the saturated fibrous base material at a predetermined temperature for a predetermined time to cure the saturated fibrous base material to form the friction material.

A method of fabricating a friction part out of composite material, the method including densifying a carbon yarn fiber preform with a matrix including at least pyrolytic carbon and a ZrO.sub.xC.sub.y phase, where 1x2 and 0y1, the matrix being formed by film-boiling or by chemical vapor infiltration from a first precursor for pyrolytic carbon and a second precursor that includes zirconium, the second precursor being a zirconium complex including an alcoxy or carboxylate ligand bonded to zirconium.

A friction material includes a base, a deposit including a friction modifier, and a resin disposed throughout the friction material. The base includes aramid fibers present in an amount of from greater than 50 weight percent to 70 weight percent, based on a total weight of the base. The base also includes a filler present in an amount from 30 weight percent to less than 50 weight percent, based on a total weight of the base. The friction material is also free of a material having a thermal degradation temperature of less than 200 C. The friction material may have a porosity of from 60% to 85% as determined using ASTM D4404-10 and a median pore size of from 0.5 m to 50 m, as determined using ASTM D4404-10.

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.sub.xC.sub.y phase, where 1x2 and 0y1, 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.sub.1 to C.sub.6 polyalcohol modified by linking the oxygen atom of at least one alcohol function to a group of formula ZrR.sub.3, the substituents R being identical or different, and R being selected from: H, C.sub.1 to C.sub.5 carbon chains and halogen atoms.

A method for forming a friction material. The method includes mixing a fibrous base material and filler particles to form a substrate. The method further includes saturating the substrate with a silane solution including a silane to form a uniformly impregnated silane matrix. The method also includes curing the uniformly impregnated silane matrix to form a cured uniformly impregnated silane matrix. The method also includes saturating the cured uniformly impregnated silane matrix with a phenolic resin solution to form a uniformly impregnated silane, phenolic resin matrix. The method also includes curing the uniformly impregnated silane, phenolic resin matrix to form the friction material.

A method of producing a friction material. The method includes mixing silica containing filler particles and a liquid binder to form a binder-filler liquid mixture. The method also includes saturating a fibrous base material with the binder-filler liquid mixture to form a saturated fibrous base material. The method further includes curing the saturated fibrous base material at a predetermined temperature for a predetermined time to cure the saturated fibrous base material to form the friction material.

A phenol resin for a wet friction material of the invention contains a resol-type phenol resin having, in one molecule, a structural unit A which is derived from a phenol compound having one phenolic hydroxyl group and a structural unit B which is derived from a polyfunctional phenol compound having two phenolic hydroxyl groups.

A method of making a wet friction material layer includes adding a media in liquid form to a material base including filler particles embedded in a matrix of fibers; drying the media to solidify the media on the filler particles such that the media plugs holes in the filler particles; adding a binder to the material base; and unplugging at least some of the holes in the filler particles by removing at least some of the media from the material base.