【摘要】 采用薄膜沸腾CVI以LaCl₃催化热解二甲苯、浸渍树脂及高温处理后获得密度为1. 72～1. 73 g/cm³的炭/炭（C/C）复合材料,应用激光热导仪、摩擦试验机及扫描电镜等研究了催化剂含量对材料导热和摩擦性能的影响。结果表明,催化剂含量由0增加至15 wt%时,材料的热导率先升高后降低,摩擦系数及磨损率的变化与之相反。含量6 wt%下材料的导热性能较高,垂直与平行摩擦面方向的热导率最大分别为40. 3和86. 1 W/（m·K）,较含量为0时提高约58. 5%和75. 6%;制动过程中,摩擦面易于形成纳米丝状碳增强的光滑摩擦膜,是该含量下材料摩擦系数和磨损较低、制动稳定性高的重要原因。更多还原

【Abstract】 Carbon/carbon composites with densities of 1.724.73 g/cm³ were fabricated by film boiling chemical vapor infiltration of a needle-pierced preform using xylene as a carbon precursor and LaCl₃ as a catalyst,followed by resin impregnation and graphitization.The effects of the catalyst content on the thermal conduction and tribological properties of the composites were investigated by SEM,thermal tests with a laser flash instrument,and friction tests.Results showed that the thermal conductivities in the through thickness and in-plane directions,the friction coefficient,and the wear rate all had maxima at 6 wt% for LaCl₃ contents from 0 to 15 wt%.The maximum thermal conductivities were about 58.5 and 75.6% higher than those of the composites without a catalyst in the through thickness and in-plane directions,respectively.A smooth friction film was most easily formed on the friction surface of the composite fabricated with a 6 wt% catalyst content,resulting in the lowest coefficient of friction and wear rate as well as the highest braking stability.更多还原