炭／陶复合材料电热性能的研究

通过在陶瓷基体原料(高岭土)中添加炭系导电原料(石墨、炭黑),经球磨混合、模压成形和烧结工艺制得炭/陶复合材料.采用X射线衍射(XRD)、扫描电镜(SEM)、数字测温仪等分析和测试了所研制试样的相组成、显微结构以及电热性能.结果表明,本实验的烧结条件下,炭系导电原料不会和陶瓷基体发生反应,其导电性不会受到影响.单一石墨和炭黑含量超过30和25wt%或石墨加炭黑混合(m石墨: m炭黑=1: 1)导电原料含量超过30wt%时,可在炭/陶复合材料内部形成良好的连续导电通道,且该材料具有优良的电发热性能.

Study on the Electric Heating Property of Carbon/Ceramic Composites

Carbon/ceramic composites were prepared by ball milling of the matrix ceramic material (kaolin) and the conductive components (graphite and carbon black) , die forming and sintering processes. The phase composition, microstructure and electric heating property were analyzed and tested using XRD, SEM and numerical thermoscope, etc. The results show that: 1) reactions are not supposed to take place between the matrix ceramic material and the carbon conductive components at the specific sintering conditions, therefore, the conductivity of the carbon materials won' t be weakened; 2 ) continuous conducting passages are formed inside the carbon/ceramic composites with the contents of graphite, carbon black and both graphite and carbon black ( m graphite:m carbon black = 1: 1) being 30, 25, 30wt% respectively, which resulting in a good electric heating property of the composites.