The invention relates to a method for preparing a C / SiC
composite material through a low-cost fused
silicon impregnation method, which comprises the following steps: performing calcining pretreatment on a
carbon felt or
graphite felt at 400-600 temperature; immersing the pretreated
carbon felt or
graphite felt in a
melamine and
boric acid solution, thus
coating a
boron nitride protective layer; immersing in a carbon /
silicon carbide slurry water solution, performing impregnation to ensure that pores of the
carbon felt or
graphite felt are fully filled with carbon /
silicon carbide, placing in a
sintering furnace, and performing primary fused silicon impregnation treatment at 1600-1800 DEG C; immersing in liquid phenolic resin, and performing
carbonization treatment under the protection of an
inert atmosphere at 800-1000 DEG C to ensure that all the resin is carbonized; and finally, performing secondary fused silicon impregnation treatment to ensure that carbon produced by
carbonization of the resin totally reacts with silicon to generate
silicon carbide, thus obtaining the C / SiC
composite material. The obtained C / SiC
composite material is high in density, low in air pore and free silicon content, and favorable in material strength,
toughness and frictional wear performance, and can be used for manufacturing of
brake pads.