Patent ID: 8349231

Claim:
A method of making a shaped composite material comprising a base layer and at least one surface layer and for controlling the coefficient of friction of the surface layer, said method comprising the following steps: a) preparing of a first mixture consisting essentially of carbon fibers and chemical binders; b) preparing of a second mixture consisting essentially of carbon fibers, powdered SiC particles, and resin, said second mixture being selected from the group consisting of: i) 25% to 60% by weight of filaments consisting essentially of carbon having a length of 5 to 8 mm, 1 to 10% by weight of SiC having a particle size from 1 to 2 mm and 40 to 75% by weight of resin in order to obtain a high coefficient of friction, ii) 10 to 25% by weight of filaments consisting essentially of carbon having a length of 1 to 5 mm, 10 to 15% by weight of SiC having a particle size from 0.1 to 1 mm, and 60 to 80% by weight of resin in order to obtain a medium coefficient of friction, and iii) 5 to 10% by weight of filaments consisting essentially of carbon having a length of 0.1 to 1 mm, 15 to 30% by weight of SiC having a particle size of 0.01 to 0.1 mm, and 40 to 70% by weight of resin in order to obtain a low coefficient of friction; c) placing said first mixture and said second mixture in a mold having the shape of the composite product, wherein said first mixture constitutes said base layer and said second mixture constitutes said at least one surface layer, and then molding the two mixtures together with the application of heat and pressure to obtain a semi-finished product; d) firing said semi-finished product at a first temperature in the range of 900° C. to 1200° C. sufficient to bring about carbonization or pyrolysis of said chemical binder; and e) after step d), firing said product in the presence of silicon at a temperature of 1400° C. to 1700° C. sufficient to cause the silicon to melt and infiltrate into the semi-finished product to obtain a finished product, wherein step b) includes a step of adjusting the quantity of SiC particles and the coefficient of friction by either increasing said quantity to decrease the coefficient of friction, or decreasing said quantity to increase the coefficient of friction.