毡体密度对C/C复合材料增密和结构的影响

用液化石油气作碳源、针刺炭毡作增强体,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,在毡体内部设置石墨纸作发热体,并研究了一次性沉积15 h后,毡体密度对增密速度和材料结构的影响.采用偏光显微镜研究了沉积炭的显微结构,用XRD均峰位法研究了材料的石墨化度,并用排水法测量材料的表观密度.研究表明, CVI工艺增密速度随毡体密度的增加呈下降趋势,而较高的毡体密度有利于获得较高石墨化度的高织构的粗糙层结构(RL)热解炭.图4,参15.

Effects of preform density on CVI rate and microstructure of carbon/carbon composites

The needle-punched carbon felt as porous preforms,liquefied petroleum gas (LPG)as hydrocarbon gas,installing special electric layer of graphite paper in performs, forming gradses of temperature and electromagnetic, C/C composites were fabricated for 15 h by chemical vapor infiltration (CVI) with multi-factor coupling physical fields,the influence of felt density on the rate of CVI and microstructure were investigated.The textural of pyrolytic carbons were observed by polarized light microscopy(PLM),and the graphitization degree of these C/C composites was analized by XRD;The results show that the rate of deposition of pyrolytic carbon is improved greatly as the decreaseing of preform density,but higher density of perform is in favor of obtaining the rough laminar of higher texture and higher degree of graphitization.4figs.,15refs.