摘要
对同一种炭/炭复合材料,经过不同温度最终热处理后的微观结构、石墨化度、导热系数和摩擦磨损性能进行了对比研究。试验表明:随着最终热处理温度的提高,易石墨化的热解炭偏振光下光学活性增强,而难石墨化的热解炭微观结构几乎没有变化;炭/炭复合材料的晶粒逐渐长大,层面间距缩小,石墨化度有较大提高;平行纤维方向的导热系数和垂直纤维方向的导热系数均有上升。另外,试验表明:随着热处理温度的提高,炭/炭复合材料的摩擦表面逐渐形成薄而致密的自润滑膜,摩擦系数在经过一个峰值后趋于平稳状态,磨损量下降明显。在1800℃热处理的材料的失重主要是由于氧化造成的,说明1800℃的热处理温度过低,对炭/炭复合材料的各项性能无影响。
After different temperatures of ultimate heat treatment (HTT), the microstructure, graphitization degree, heat transfer coefficient and the tribological properties of the carbon-carbon composite are studied. The results show that with the increase of the HTT's temperature, the pyrocarbon of rough lamina's optical activity is increased while the smooth lamina's microstructures have not any change analyzed under polarized light; the pyrolytic carbon's interlayer distance is decreased when the crystal size and graphitization degree are increased; the heat transfer coefficient in either parallel or perpendicular directions of the fiber is increased. At the same time, with the increase of the HTT's temperature, a thin and dense film on the friction surface is formed which leads to a reduction of friction coefficient wear loss. The results also show that the HTT's temperature of 1800°C is too low to make any influence on the carbon-carbon composites and the most wear loss is due to oxidation of composites.
出处
《航空材料学报》
EI
CAS
CSCD
2004年第1期22-27,共6页
Journal of Aeronautical Materials
