溶胶-凝胶和碳热还原法合成碳化硅晶须的研究

SiC WHISKER SYNTHESIZED BY SOL-GEL AND CARBOTHEMAL REDUCTION REACTION

以工业硅溶胶和炭黑为主要原料 ,用溶胶 -凝胶和碳热还原法合成了SiC晶须 .获得的产物中碳化硅质量分数高于 95 % ,碳化硅晶须质量分数高于 74% .碳化硅晶须为直线形 ,具有光滑的表面 ,直径为 0 .2～ 0 .5 μm ,长径比约为 5 0～ 2 0 0 .对影响碳化硅晶须产率和微观结构的主要因素进行了研究 ,结果表明 :采取原料中碳含量稍多于理论值 ,并且严格控制反应温度 。

SiC whisker was synthesized with industry silicasol and carbon black by sol-gel method and carbothermal reduction reaction. The mass fraction of SiC in the product is above 95%, and SiC whisker more than 74%. SiC whisker is rectilinear and has smooth surface, with the diameter of 0.2-0.5 μm and the length to diameter ratio of about 50-200. The main factors affecting the productivity and microstructure of SiC whisker were studied. The results indicate that it is very effective to increase the mass content of SiC whisker by using the amount of C a little more than the theoretical value and by controlling the reaction temperature to mate the formation of SiC with the growth of SiC whisker.