【摘要】 以煅烧石油焦、煤沥青、锆粉及硅粉为原料,采用热压工艺制备了一系列掺杂再结晶石墨。研究了掺杂组元对再结晶石墨的热导率、电阻率和抗弯强度的影响以及微观结构的变化。结果表明,掺杂锆使再结晶石墨的基本物理性能及其微晶结构有较大幅度的改善。在含锆石墨材料中,适当掺杂硅可提高材料的热导率,但是当锆的掺杂量为9％、硅的掺杂量大于2％(质量分数)时,再结晶石墨的常温热导率降低。双组元掺杂锆、硅使再结晶石墨的导电率和力学性能下降。在再结晶石墨中,掺杂的锆以碳化锆的形式存在,掺杂的硅大都以气态形式逸出,只有微量的硅以碳化硅的形式存在。更多还原

【Abstract】 The bi-element doped recrystallized graphite was prepared from calcined coke, coal-tar pitch, zirconium and silicon by hot-pressing progress in order to investigate the effects of dopants on the thermal conductivity, electrical resistivity, bending strength and microstructure. Results showed that the basic physical properties and microstructure of recrystallized graphite with dopant zirconium was improved. The thermal conductivity of RG-ZrSi-92 with 9% of dopant zirconium and 2% (mass fraction) of dopant silicon was 380 W/(m·K). The thermal conductivity of bi-element doped recrystallized graphite with 9% of dopant zirconium and more 2% of dopant silicon decreased at ambient temperature. The electrical conductivity and bending strength of bi-element doped recrystallized graphite decreased with increasing the amount of dopant silicon. The zirconium added in carbon substrate was in form of ZrC precipitates, but a little of silicon existed in form of SiC precipitates.更多还原