摘要：采用多热源真空合成法,以纯度分别为99%(质量分数,以下同)、90. 87%的微米级硅质原料、碳质材料,在自行研制的多热源炉内合成高纯、高密度、大粒径的3C-SiC微粉。实验研究碳硅物质的量比、原料粒度以及反应温度对合成产物的影响。结果表明:碳与硅物质的量比为1. 05∶1时,合成的3C-SiC微粉SiC的纯度达到99. 99%;与硅质原料相比,碳质原料粒度对产物粒度影响更为显著,增加碳质原料的粒度,可获得粒度更大、晶型更完整的3C-SiC微粉,微粉的平均粒径D₅₀可达21. 7μm;在1 300～1 800℃内,温度越高,产物晶型愈完整,粒径更大,结构更致密,平均密度可达3. 212 g/cm³。

关键词：多热源真空合成法；高纯度；高密度；大粒径；3C-SiC微粉

Abstract: 3C－SiC micropowder of high purity，high density and large particle size which used the micron grade silicon and carbon materials with mass fraction of 99% and 90．87% respectively as raw materials were prepared by vacuum synthesis with multiple heat sources．The effects of of the ratio of carbon and silicon，raw material size and reaction temperature were studied ．The results show that the ratio of carbon and silica has an effect on the reaction speed and the product purity，the 3C－SiC micropowder synthesized can reach 99．99% when the ratio of carbon and silicon is 1．05∶1．Compared with the silica materials，the particle size of carbon material has a more significant effect on the product granularity，the larger and higher purity 3C－SiC micropowder can be prepared when the carbon material is bigger in a certain extent．The average particle size D₅₀ of micropowder can reach 21．7 μm．In 1 300～1 800 ℃，the higher of the temperature is， the more completeness，bigger and compacter of the products are，and the density can be 3．212 g /cm³． 

Keywords: vacuum synthesis with multiple heat sources; high purity; high density; large particle size; 3C－SiC micropowder