【摘要】 用液化石油气作碳源、炭毡作增强体,在坯体中埋置导电层产生温度场和电磁场梯度,在自行设计的多元耦合物理场 CVI 炉中制备炭/炭(C/C)复合材料,并就沉积温度、压力、碳源气体浓度等工艺条件对增密速度和材料结构的影响作了探讨性研究。采用偏光显微镜研究了沉积炭的显微结构。研究表明,多元耦合物理场 CVI 工艺增密速度快,初始密度为0.2g/cm~3,尺寸为260mm×60mm×20mm 的坯体,在920℃、3kPa、碳源浓度45%的条件下沉积20h,试样的密度达到1.71g/cm~3;在960℃、0.1kPa、碳源浓度45%的条件下,可获得结构一致的粗糙层结构(RL)热解炭。更多还原

【Abstract】 Using carbon felt as porous performs and liquefied petroleum gas(LPG)as hydrocarbon gas,in- stalling special electric layer in performs to form gradses of temperature and electromagnetic,C/C composites were fabricated by chemical vapor infiltration(CVI)in multi-factor coupling physical fields,and the infiltration conditions have been optimized.The texture of pyrolytic carbons were observed with polarized light microscopy(PLM).The re- suits show that,with multi-factor coupling physical fields,the rate of deposition of pyrolytic carbon has been im- proved greatly,the porous carbon-carbon performs,260mm×60mm×20mm,under the infiltration conditions of 920 ℃、3kPa、45%,can be densified in one-cycle,C/C composites with density of more than 1.7g/cm~3 are obtained in 20h. Though optimizing the infiltration conditions,some kinds of microstructure of pyrolytic carbons can be obtained, range from rough laminar,smooth laminar,isotropie and banded structure.For exemple,in the infiltration conditions of 960℃、0.1kPa、45%,the rough laminar of higher texture can be obtained.更多还原