▎ 摘　　要

NOVELTY - Preparing modified carbon fiber toughened silicon carbide ceramic material involves: (1) grafting graphene oxide on carbon fiber surface with silane coupling agent, curing, and cracking to form graphene oxide modified carbon fiber; (2) introducing the obtained product into a fluidized bed reactor, pyrolyzing aluminum sec-butoxide to obtain aluminum oxide, and depositing on the surface of graphene oxide modified carbon fiber to form graphene oxide modified carbon fiber coated with aluminum oxide; (3) taking obtained product as a substrate, and depositing a silicon carbide layer on the substrate surface to form a modified carbon fiber; (4) mixing silicon carbide powder, modified carbon fiber and sintering aid, adding to a ball mill, then adding phenolic resin and graphite powder, and ball milling; (5) vacuumizing obtained slurry, dry pressing, and solidifying; and (6) heating the obtained product, heat-preserving, sintering, and cooling along with furnace. USE - The method is useful for preparing modified carbon fiber toughened silicon carbide ceramic material (claimed) used for high-temperature kiln furniture, combustion nozzle, heat exchanger, sealing ring, and sliding bearing, and as bulletproof armor material, space mirror, fixture material for semiconductor wafer preparation, and nuclear fuel cladding material. ADVANTAGE - The method provides silicon carbide ceramic material, which uses carbon fibers of graphene oxide layer, aluminum oxide layer, and silicon carbide layer that are sequentially coated from inside to outside used for toughening to form multilayer protective structure, thus greatly improving the oxidation resistance of the carbon fiber and improving the toughness of the silicon carbide ceramic material. DETAILED DESCRIPTION - Preparing modified carbon fiber toughened silicon carbide ceramic material involves: (1) oxidizing surface of carbon fiber, grafting graphene oxide on the surface of carbon fiber with silane coupling agent, then coating a polycarbosilane precursor solution on the surface of graphene oxide modified carbon fiber, curing, and high temperature cracking to form graphene oxide modified carbon fiber; (2) introducing the graphene oxide modified carbon fiber into a fluidized bed reactor, using argon as a carrier gas, and aluminum sec-butoxide as an aluminum source, pyrolyzing aluminum sec-butoxide in the reactor to obtain aluminum oxide, and depositing on the surface of graphene oxide modified carbon fiber to form graphene oxide modified carbon fiber coated with aluminum oxide; (3) taking the obtained product as a substrate, trichloromethylsilane, hydrogen and argon as gas sources, and depositing a silicon carbide layer on the surface of the substrate by chemical vapor deposition method to form a modified carbon fiber; (4) mixing silicon carbide powder with a particle size of 45-75 microns, modified carbon fiber, and sintering additive, adding to a ball mill, then adding phenolic resin, graphite powder, and deionized water, and ball milling; (5) vacuumizing the obtained slurry in a vacuum pressure tank, injecting into a mold for dry pressing, and then solidifying at 50-90degrees Celsius for 6-12 hours; and (6) heating the obtained product at a heating rate of 5-10degrees Celsius/minute to 1400-1500degrees Celsius in a vacuum furnace under an inert atmosphere, heat-preserving and sintering for 2-6 hours, and cooling along with the furnace. An INDEPENDENT CLAIM is included for the modified carbon fiber toughened silicon carbide ceramic material.