碳纤维诱导法制备SiC晶须的工艺及机理  

GROWTH PROCESS AND MECHANISM OF SiC WHISKERS BY INDUCTION OF CARBON FIBER

作　　者：黄凤萍[1] 李贺军[1] 卢锦花[1] 李克智[1] 郭领军[1] 

机构地区：[1]西北工业大学超高温复合材料重点实验室,碳/碳复合材料工程技术研究中心,西安710072

出　　处：《硅酸盐学报》2007年第5期643-647,共5页Journal of The Chinese Ceramic Society

基　　金：国家杰出青年基金(50225010)资助项目

摘　　要：以碳化稻壳为原料、碳纤维为诱导相制备碳化硅晶须。用X射线衍射、电子显微镜分析所制晶须的组成和形貌。结果表明:晶须依附于碳纤维生长,实现了晶须与反应残余物的自动分离。晶须为纯β-SiC晶须,直径为0.5～2μm,长度为100～500μm,表面光滑,在晶须中没有发现夹杂物及球晶,晶须的获得率为100%。晶须尖端平整,未出现催化剂溶球,说明晶须以气相合成机制生长。从热力学角度阐述了晶须气相结晶生长的机理。Silicon carbide whiskers were prepared by the induction of carbon fiber and using carbonized rice hulls as raw materials. The composition and morphology of the whiskers were analyzed by X-ray diffraction and electron microscopy. The experimental results show that the SiC whiskers are formed attached to carbon fibers, and are kept separate from the residue spontaneously. The diameters of the whiskers are 0.5-2 μm, and the lengths are 100-500 μm. Whiskers with smooth surfaces consist of straight β-SiC crystals. No inclusions are found in the whiskers, and the achievable rate of SiC whiskers is 100%. There are no catalyst bulbs on the tips of the whiskers. The mechanism of whisker growth is vapor synthesis according to the discussion based on the thermodynamic points.

关 键 词：碳化硅晶须 碳纤维 稻壳 诱导生长 

分 类 号：TB332[一般工业技术—材料科学与工程]