激光法制备高纯纳米SiC粉体及其产率

以硅烷SiH4和乙烯C2H4为反应原料,采用激光诱导化学气相沉积法(LICVD)制备了高纯、低团聚、近球形的理想纳米SiC粉体.用化学分析、X射线衍射(XRD)、透射电子显微镜(TEM)及比表面积(BET)等分析测试手段对粉体进行了表征,结果表明粉体中SiC含量高于98%,平均粒径为20nm,晶体结构为β-SiC,粉体产率大于200g/h,粉体中氧含量低于1%,且主要是表面的吸附氧;从能量和反应气流量两个方面对粉体产率进行了理论分析,在此基础上推导出了粉体产率公式,与实际粉体产率基本一致.

Synthesis of high pure nanometer SiC powders by laser method and its production rate

In this paper , spherical and ideal nanometer SiC powders with high purity and low agglomeration were synthesized by Laser Induced Chemical Vapor Deposition (L ICVD) method with SiH₄ and C₂H₄ as starting materials. The powders produced were characterized by chemical analysis , XRD , TEM and BET techniques.The result s show that the powders of β2SiC crystallization has a purity of above 98 %of SiC in weight with average diameter of 20 nm and less than 1 % oxygen content in weight that is mainlabsorbed on the surface of the powders. In addition , two formulas for calculation of the theoretical production rate of nanometer SiC powders synthesized by L ICVD were conducted f rom the energy exchange between laser beam and reactant s of SiH₄ and C₂H₄ and the flow rate of SiH₄ , respectively. The two formulas are basically coincident with the actual SiC production rate of more than 200 g/ h , and the one obtained f rom energy exchange point s out the direction of enlarging production rate of SiC powders and adjusting process parameters , so it has a theoretical and practical meaningto the indust rial production.