合成温度对C/C复合材料表面SiC纳米线制备的影响

Effect of Synthesis Temperature on Fabricating SiC Nanowires on C/C Composites

为了提升C/C复合材料表面SiC涂层的韧性及其与基体的结合强度,以三氯甲基硅烷为前驱体,采用常压化学气相沉积法在C/C复合材料表面制备了SiC纳米线,研究了不同合成温度对纳米线的物相、形貌和结构的影响。借助XRD、SEM、TEM和EDS对所制备的纳米线进行物相、形貌和结构的表征,结果表明1300℃下可制备得到较为纯净的Si C纳米线,形状平直,表面光滑,取向随机呈网状分布,直径大约为100~160 nm,长度可达几百微米;随着合成温度的不断升高,纳米线的物相逐渐由β-SiC和Si双相转变为单一的β-SiC相,其中Si相是以单晶Si纳米线的形式夹杂在SiC纳米线中;另外,纳米线的沉积速率也随着温度的升高大幅度增加,产量增多,致密性增高。

To improve the toughness and bonding strength with C/C composites of SiC coating,SiC nanowires have been fabricated on C/C composites by chemical vapor deposition method using methyltrichlorosilane as precursor at standard atmospheric pressure and the effect of synthesis temperature on the phases,morphologies and structures of nanowires were investigated. The phases,morphologies and structures of as-received nanowires were characterized by XRD,SEM,TEM and EDS. The results show that pure SiC nanowires can be prepared at the temperature of 1300 ℃,the SiC nanowires are straight with smooth surface and the orientation is randomly distributed in a network. The SiC nanowires' diameters are in the range of 100 ~ 160 nm,and lengths are up to hundreds of micrometers. The phases of nanowires change from β-SiC and Si to single β-SiC with the temperature increasing,and the Si phase is doped with SiC nanowires in the form of single crystal Si nanowires. Moreover,the deposition rate,output and density of the SiC nanowires are observably improved with the increase of synthesis temperature.