工艺参数对CVD制备热解碳界面层厚度的影响

Effects of process parameters on thickness of pyrolytic carbon interface layer by CVD

以甲烷(CH4)为碳源先驱体,以三维针刺碳纤维预制体为沉积基体,研究了化学气相沉积(chemical vapor deposition,CVD)工艺过程中沉积时间、沉积压力以及预制体厚度对热解碳界面层沉积厚度的影响,并在此基础上优化了在碳纤维表面制备合适厚度的热解碳界面层所需的CVD工艺参数。结果表明,针对现有反应腔体,5 mm厚碳纤维预制体试样,采用1 000℃的沉积温度,CH4流速500 ml/min,沉积时间10 h,沉积压力5 kPa,可在预制体内外碳纤维表面沉积得到厚度合适的热解碳界面层;当碳纤维预制体厚度增至10 mm,则沉积时间应延长至15 h,压力维持不变,可沉积得到合适厚度的界面层。

By taking methane(CH4) as carbon source precursor gas and 3D needle-punched carbon fiber-prefabricated form as the deposition matrix,the effects of the deposition time,pressure and prefabricated form thickness in chemical vapor deposition(CVD) process on the thickness of pyrolytic carbon(PyC) interface layer were studied.Based on the study,the CVD technological parameters needed by preparing PyC interface layer with appropriate thickness on the surface of carbon fiber were optimized.Analysis on these effects reveals that,based on the existing furnace,with a deposition temperature of 1 000 ℃ and CH4 flow speed of 500 ml/min,deposition period 10 h and deposition at 5 kPa can produce the PyC interface layer with suitable thickness on the inner and outer surface of the fiber-prefabricated form with 5 mm thickness.If the thickness of carbon fiberprefabricated form needs to be increased to 10 mm,the deposition period should be prolonged to 15 h while the pressure keeps 5 kPa.