(中南大学 粉末冶金国家重点实验室,长沙 410083)
摘 要: 以碳/碳复合材料为基体,MTS为先驱体原料,采用化学气相沉积法在复合材料表面制备CNT-SiC/SiC复合涂层;研究原位生长的碳纳米管(CNTs)对SiC沉积速度和微观形貌的影响。结果表明:CNTs加快SiC的沉积,涂层的平均质量增加速率提高5%,提高沉积的均匀性,且晶粒更细小;经1 100 ℃恒温氧化10 h后,单一SiC涂层、CNT-SiC/SiC涂层的质量损失率分别为41.11%和34.32%;经(1 100 ℃,3 min)↔(室温,3 min)热循环15次后,单一SiC涂层和CNT-SiC/SiC涂层的质量损失率分别为33.17%和30.25%,部分区域涂层脱落及涂层表面形成的气孔是涂层试样质量损失的主要原因。
关键字: 碳/碳复合材料;CNT-SiC/SiC复合涂层;碳纳米管;化学气相沉积;氧化
deposition SiC coatings
(State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China)
Abstract:The CNT-SiC/SiC composite coating was deposited on carbon/carbon composites by chemical vapor deposition (CVD) with methyltrichlorosilane (MTS) as the precursor. The SiC deposition rate and surface micro- morphology of the in-situ growth CNTs sample were investigated. The results show that CNTs accelerates the SiC deposition rate and improves the deposition uniformity, the average mass gain rate is improved by 5% and finer grain SiC is obtained. After oxidation at 1 100 ℃ for 10 h, the mass losses of the single SiC and CNT-SiC/SiC coated samples are 41.11% and 34.32%, respectively. After thermal cycling between (1 100 ℃, 3 min) and (room temperature, 3 min) for 15 times, the mass losses of the single SiC and CNT-SiC/SiC coated samples are 33.17% and 30.25%, respectively. The mass loss of the coated samples is mainly resulted from the debonding of some coating and the formation of holes on the coating surface.
Key words: carbon/carbon composites; CNT-SiC/SiC composite coating; CNTs; chemical vapor deposition; oxidation