掺钛石墨导电性及其微观结构的研究

研究了不同钛掺杂量的再结晶石墨的电阻率与微观结构。以探讨掺杂组元对材料导电性能的影响。实验结果表明，与相同工艺条件下制得的纯石墨相比，掺钛石墨具有高密、高石墨化程度以及极低的电阻率的特点，微观结构分析表明，钛对材料的石墨化过程中具有催化作用，掺杂石墨材料中钛掺杂量对材料的石墨化程度有很大影响：少量钛掺杂量即可使材料达到高的石墨化程度，过多钛掺杂量不利于其电阻率的降低，分析表明钛元素在材料中是以碳化钛形式存在，但在制备过程中，有少量钛逸失，雁而在材料表面形成孔隙，而这些对材料的性能有不利的影响。

MICROSTRUCTURE AND ELECTRICAL PROPERTIES OF TITANIUM DOPED GRAPHITE

Microstructure and electrical properties of titanium doped graphite were investigated in order to discuss the effects of titanium dopant on the doped graphite. Results show that the doped graphite demonstrates characteristics of high density, high graphitization degree and much lower electrical resistivity than pure graphite produced by same process. Microstructure analysis reveals that titanium dopant severs as a catalyst to accelerate the graphitization of carbon substrate, and the graphitization degree shows a strong dependence on titanium concentration in the doped graphite. For the doped graphite with titanium concentration of 11 W/%, its electrical resistivity is as low as 2.10 μΩm and graphitization degree reaches 100 %. Composition analysis indicates that titanium added to the carbon substrate is in form of TiC precipitates and a small amount of titanium has been depleted out of the doped graphite, which will result in the formation of cavities. To develop titanium doped graphite with high performance, titanium concentration and preparation process should be optimized.