反应温度对纳米SiC纤维制备的影响

Effect of Reaction Temperature on Preparation of Nano SiC Fibers

采用化学气相反应法在碳纤维织物表面生长纳米SiC纤维,通过对不同温度下制备纳米SiC纤维的微观形貌及产量等进行分析,优化出较为合适的工艺温度。结果表明,当采用Micro-Si/Nano-SiO_2混合粉作为反应原料时,反应温度低于1410℃时不利于纳米SiC纤维的大量生成,反应温度为1420℃时制备出的纳米SiC纤维具有较好的均匀性,所制备纳米纤维直径约为140～320 nm,制备纳米SiC纤维后碳纤维织物的净增重率接近6%,反应温度为1460℃时,由于反应温度过高导致出现了较高密度的层错堆垛,制备的纳米纤维出现明显的弯曲甚至打结现象。

Nano SiC fibers were prepared on the surface of carbon fabric by chemical vapor reaction.The influence of the reaction temperature was studied.The microstructures of nano SiC fibers prepared at different temperatures were analyzed by scanning electron microscopy(SEM)and the yield of nano SiC fibers was calculated based on the weight gain of carbon fabric.The results show that the yield of nano SiC is low at 1410℃or below.The optimized temperature is 1420℃,at which uniform nano SiC fibers with diameters between 140~320 nm are prepared,with a close to 6%net weight gain of the carbon fabric,while nano SiC fiber could still form at 1460℃but with obvious curls and knots,It may be that higher temperature leads to high density of stacking faults.