LSP法制备硅化石墨的主要影响因素

Major factors affecting silicated graphite preparation by LSP method

详细探讨了用LSP法制备硅化石墨的影响因素 ,结果表明 ,基料的热膨胀系数 ,石墨化与否 ,孔隙特征等物性以及温度、时间、真空度等硅化条件是决定基料硅化效果的关键因素。

Silicated graphite is a new type carbon-graphite base compound material characterized by excellent performance and extensive application. Physical property and silication condition of carbon-graphite base material are two key factors affecting silicated graphite preparation by LSP method. According to plenty of tests, the physical property of the base material must have expansion coefficients between 3.7×10 -6 /℃ and 5.3×10 -6 /℃ and approximately match the SiC expansion coefficient; the base material must be isotropic and experience graphitization; the porosity is about 50% and the open holes possess no less than half of total holes; the smaller the open holes and the bigger the inside and outside surface areas, the better the condition will be. The optimum silication conditions seem to be 1?900℃～2?000℃ in temperature, 1 h in time, more than two times of silication and vacuum degree ≥10 -3 Pa.