Abstract: There are adopted CVD method and acquired unifonn Si coating on the surfaee of carbon fibers(CF),analyzed further phase structure of Si coating,researched that influenee of Si coating on the oxidation resistance and tensile strength properties of CF. Experimental results show that the phase structure of Si in the coating is noncrystaline; Si coating can rise the oxidation resistance of CF; which the oxidation temperatures are at 400℃ and 500℃,Si coat- ing CF oxidated have the increase of weight stage; but which oxidation temperature is up to 600℃,Si coating CF have only weight loss stage, meanwhile Si coating have the tensile strength of CF depressed,but the comfort air oxidation may have the tensile strength of CF improved further,while the oxidation times are stretched,the tensile strength of coating CF is increasing progressively at 400℃ and it is increasing as a starter and then dropping at 500℃;but which the oxidation temperature is up to 600℃,the tensile strength of coating CF is in- creasing quickly as a starter and then droppinng rapidly.

Key words: carbon fibers, vapor deposition, silicon, high temperature environment