CAJ | 학술논문

采用不同的预制体和致密化方法制备了密度不同的5种炭/炭复合材料(密度范围1.77g/cm3～1.85g/cm3).用氧-乙炔焰对试样进行了烧蚀试验,并用SEM表征了烧蚀后材料的形貌.结果表明: 烧蚀后,与乙炔焰成30o角的纤维变成楔形,而与火焰平行的纤维变成直径为3.5μm～4.5μm的针状,针状纤维更易被火焰烧蚀而钝化.部分宏观孔(直径为1.0mm～1.26mm)、针状微孔及界面裂纹等缺陷处更易被烧蚀而变成烧蚀坑.包裹纤维的沥青炭层由于热解炭基体的不连续而出现了严重的剥蚀.高密度材料(1.85g/cm3)具有良好的抗烧蚀性能.
채용불동적예제체화치밀화방법제비료밀도불동적5충탄/탄복합재료(밀도범위1.77g/cm3～1.85g/cm3).용양-을결염대시양진행료소식시험,병용SEM표정료소식후재료적형모.결과표명: 소식후,여을결염성30o각적섬유변성설형,이여화염평행적섬유변성직경위3.5μm～4.5μm적침상,침상섬유경역피화염소식이둔화.부분굉관공(직경위1.0mm～1.26mm)、침상미공급계면렬문등결함처경역피소식이변성소식갱.포과섬유적력청탄층유우열해탄기체적불련속이출현료엄중적박식.고밀도재료(1.85g/cm3)구유량호적항소식성능.
Five carbon-carbon composites were prepared with different fibre orientations in the preform and were densified by different methods. Their ablation behaviour was examined by an oxy-acetylene test and scanning electron microscopy. The densities of the composites were in the range of 1.77 to 1.85g/cm3. Fibres having an angle of 30° with the oxy-acetylene flame turned into a sharp wedge shape, whereas fibres parallel to the flame had a needle-like shape with diameter up to 3.5-4.5μm after ablation. The needled fibres were easily attacked and ultimately became blunt. Partially filled macropores with sizes of 1.0-1.26mm, needle pores, interfacial cracks and gaps in non-woven cloth were easily attacked by the flame, resulting in macroscopic ablation pits that decreased with increasing density of the composites. The needled fibres around pitch carbon layers were severely denuded due to their discontinuity with the pyrolytic carbon matrix. A high density (1.85g/cm3) composite had an excellent ablation resistance.