粘结剂含量对石墨材料电、热传导性能的影响

以煅后石油焦和煤沥青为基本原料，采用热压工艺制备了一系列石墨材料。考察了粘结剂含量对石墨材料电、热传导性能的影响。在实验基础上，阐明了粘结剂与骨料颗粒在热混捏与热压过程中相互作用原理。结果表明，石墨材料的传导性能不仅依赖于原料种类、粒度，而且与其质量百分配比也有关系。经过分析认为，粘结剂含量小于25W／％时，随着粘结剂含量的增加，石墨材料传导性能增强的原因可归结为石墨材料的骨料颗粒气孔率得到降低和颗粒间微裂纹减少所致；而粘结剂含量超过25W／％时，材料的传导性能随着粘结剂含量的增加而降低的原因可归结为骨料颗粒间粘结剂的γ组分以气态形式挥发使得材料气孔率增加所致。

EFFECT OF THE BINDER CONTENT ON THE ELECTRICAL AND THERMAL CONDUCTIVITY OF BULK GRAPHITE

Bulk graphite was prepared from starting materials of calcined coke and coal tar pitch by the hot pressing process. The effect of binder content on the electrical and thermal conductivity of the bulk graphite has been investigated. Based on the experimental results, the interaction mechanism of the calcined coke grain and the binder was proposed with the hot binding and hot pressing process. Results show that the electrical and thermal conductivity of the bulk graphite was strongly dependant on the type, granularity and content of the starting materials. The reason why the conduction increased with increasing the binder content up to 25?W/% might be attributed to the filling of pores in the calcined coke by the binder and the resulting densification of the bulk graphite. A binder content more than 25?W/% led to an increase in the porosity and a decrease in electrical and thermal conductivity.