材料期刊网

制备了Si、Ti双组元和Si、Ti、B4C三组元掺杂石墨材料并研究了其结构和性能．实验结果表明，与相同条件下制得的纯石墨材料相比，掺杂石墨材料具有高密度，高强度以及极低的电阻率等特点．双组元掺杂石墨的导电性略优于三组元掺杂石墨，但其机械强度却明显低于后者．分析表明：各组元在材料中所起的作用各不相同，钛、硼添加剂对材料的机械强度有增强作用，对材料的石墨化具有催化作用；少量硅的添加有利于石墨材料的石墨化程度以及导电性能的提高，但含量较多时，由于Si的大量逸失导致气孔率增大，使掺杂石墨的导电性及机械性能降低．

Microstructure and some basic properties of Si, Ti (bi-element) and Si, Ti, B4C(th-element)doped graphite were investigated in order to discuss the effects of dopants. Experimental results show that allthe doped graphite materials posses high level of densitication & graphitization and much lower electrical resis-tivity compared with pure graphite produced by the same process. Microstructure analysis indicates that dop-ants serve as catalysts to accelerate graphitization. But there is still some difference between the bi-and th-ele-ment doped graphites, bi-element doped graphite shows a higher electrical resistivity and a lower mechanicalstrength. However, the electrical conductivity and mechanical strength of the doped graphite materials de-crease with further increasing Si addition, as a result of the formation of large cavities because of the evapora-tion of Si during high temperature processing. To develop multi-element doped graphite materials with highperformance, the dopants concentration and preparation process should be optimized.