Oxidation resistance of SiC nanowires reinforced SiC coating prepared by a CVD process on SiC‐coated C/C composites
Oxidation resistance of SiC nanowires reinforced SiC coating prepared by a CVD process on SiC‐coated C/C composites
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DOI：
10.1111/ijac.12893
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发表时间：
2018-09
影响因子：
2.1
通讯作者：
Xinfa Qiang;Hejun Li;N. Zhang;Yunfan Liu;Song Tian
中科院分区：
文献类型：
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作者：
Xinfa Qiang;Hejun Li;N. Zhang;Yunfan Liu;Song Tian
采用简单的化学气相沉积（CVD）工艺在包埋SiC涂层C/C复合材料表面制备了抗氧化SiC纳米线增强SiC（SiCNWs-SiC）涂层。这种双层SiCNWs-SiC/PC-SiC涂层体系既具有SiC缓冲层的优点，又具有SiCNWs的增韧效果。利用SEM、TEM和XRD对纳米线和涂层的微观结构和相组成进行了分析。具有孪晶和堆垛层错的单晶β-SiC纳米线均匀地沉积并且随机取向，直径为50 - 200 nm，长度为几微米到几十微米。通过SiC纳米晶在SiCNWs表面的紧密堆积，获得了具有一定孔隙的致密SiCNWs-SiC涂层。在涂层体系中引入SiCNW后，涂层的抗氧化性能得到有效提高。氧化试验结果表明，SiCNWs-SiC/PC SiC涂层样品在1073 K氧化8 h和1473 K氧化276 h后的失重率分别为4.91%和1.61%。无论在哪个温度下氧化，SiCNWs-SiC/PC SiC涂层系统的抗氧化性能均优于单层PC SiC涂层或不含SiCNWs的双层CVD SiC/PC SiC涂层。
Oxidation protective SiC nanowires‐reinforced SiC (SiCNWs‐SiC) coating was prepared on pack cementation (PC) SiC‐coated carbon/carbon (C/C) composites by a simple chemical vapor deposition (CVD) process. This double‐layer SiCNWs‐SiC/PC SiC‐coating system on C/C composites not only has the advantages of SiC buffer layer but also has the toughening effects of SiCNWs. The microstructure and phase composition of the nanowires and the coatings were examined by SEM, TEM, and XRD. The single‐crystalline β‐SiC nanowires with twins and stacking faults were deposited uniformly and oriented randomly with diameter of 50‐200 nm and length ranging from several to tens micrometers. The dense SiCNWs‐SiC coating with some closed pores was obtained by SiC nanocrystals stacked tightly with each other on the surface of SiCNWs. After introducing SiCNWs in the coating system, the oxidation resistance is effectively improved. The oxidation test results showed that the weight loss of the SiCNWs‐SiC/PC SiC‐coated samples was 4.91% and 1.61% after oxidation at 1073 K for 8 hours and at 1473 K for 276 hours, respectively. No matter oxidation at which temperature, the SiCNWs‐SiC/PC SiC‐coating system has better anti‐oxidation property than the single‐layer PC SiC coating or the double‐layer CVD SiC/PC SiC coating without SiCNWs.