化学气相沉积法碳纤维表面连续涂覆B_4C的研究

A Study of the Carbon Fiber Coated Continually with B_4C by CVD Method

以 H2 ,CH4,BCl3为原料气 ,用化学气相沉积 (CVD)法在碳纤维表面连续涂覆 B4C。通过对 CVD法各种影响因素 (沉积温度、反应物流量比、走丝速度 )的讨论 ,得到了最佳涂覆条件 :BCl3/ CH4=3/ 5 ,H2 过量 ,沉积温度110 0℃ ,走丝速度 1m/ min。对涂层物质进行定性分析后通过对涂层 Cf 和未涂层 Cf进行电镜观察 ,并做了差热分析和单丝强度测试 ,结果表明涂层效果较好 ,且抗热氧化性和单丝强度都有明显提高。

WT5BZ]Using H 2,CH 4,BCl 3 as raw materials,carbon fibers were coated with B 4C by CVD method. The best coating condition like BCl 3/CH 4=3/5,H 2 excessive ,deposition temperature(1150℃)and fiber walking speed(1m/min) was got by the discussion of several influential factors such as the temperature,the ratios of reaction gases and fiber walking speed Comparing the TG DTA ,the SEM and the straining strength of coated fibers and raw fibers,we can find that the properties of coated fiber is improved。