含Ti组元炭/炭复合材料微观结构和热传导/力学性能的研究

Microstructure and Conductive/Mechanical Properties of Carbon/Carbon Composites Including Ti

以短切炭纤维、中间相沥青和Ti粉为原料,采用模压成型、炭化、致密化、高温石墨化等一系列常规工艺,制备了含Ti组元的炭/炭复合材料。考察了Ti组元的添加对复合材料传导性能和微观结构的影响,结果表明:Ti组元的添加能增强复合材料界面、促进晶粒的完善和长大,提高材料的传导/力学性能。当Ti含量为7.3%时,2500℃高温石墨化后所制复合材料的面向热导率最高,为482W/(m.K);进一步3000℃高温处理后材料面向热导率达556W/(m.K)。同时本文探讨了Ti组元的催化石墨化机理。

Carbon/carbon composites containing Ti were prepared using chopped carbon fiber, mesophase pitch and Ti powder by the traditional process including molding,carbonization,densification and graphitization.The influence of titanium on the microstructure and properties of the carbon/carbon composites were tentatively investigated.Results show that Ti can improve the interface bonding,promotes the graphitization and perfect degree of graphite crystallite size and enhance the conductive/mechanical properties of the composites effectively.The highest thermal conductivity is 482W/(m·K) when the content of titanium is 7.3wt% at heat treat temperature(HTT) of 2500℃and the thermal conductivity increases up to 556W/(m·K) when HTT reach 3000℃.And the mechanisms of catalytic graphitization of Ti element to carbon carbon/carbon composites are also discussed.