Hafnium and silicon carbide multilayer coatings for the protection of carbon composites
Hafnium and silicon carbide multilayer coatings for the protection of carbon composites
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DOI：
10.1016/j.surfcoat.2013.06.022
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发表时间：
2013-09
影响因子：
5.4
通讯作者：
C. Verdon;O. Szwedek;S. Jacques;A. Allemand;Y. Petitcorps
中科院分区：
文献类型：
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作者：
C. Verdon;O. Szwedek;S. Jacques;A. Allemand;Y. Petitcorps
保护碳/碳复合材料的表面在高温下不被氧化的解决方案是结合联合收割机耐火碳化物，例如铪和碳化硅（HfC和SiC）。它们的沉积已经在平坦衬底上进行了研究，并且在高温下（在空气中在2000 °C下几分钟）提供了主要的抗氧化保护。这些碳化物层的渗透已被观察到内部的开放孔隙的碳基板，提高了附着力的protection.The低压化学气相沉积（LPCVD）的过程中开发这里允许多层HfC/SiC deposition。根据实验条件（温度、压力、稀释度），HfC涂层具有各种形态和厚度。这种碳化物首次沉积在平坦的石墨基底和碳单纤维上。其次，研究了C/C复合材料和碳纤维表面的多层涂层沉积。最后，碳化氢层已渗透到碳纤维束内部。为了避免碳纤维上的缺口效应，在碳化物生长之前沉积了一薄层热解碳（50 nm厚）。所有涂层都是在热壁CVD反应器中完成的，并通过扫描电子显微镜对其形貌和化学成分进行表征。
A solution to protect the surface of a carbon/carbon composite from oxidation at high temperature is to combine refractory carbides, such as hafnium and silicon carbides (HfC and SiC). Their depositions have been studied on flat substrates and present major protection against oxidation at high temperature (several minutes at 2000 °C under air). The infiltration of these carbides layers has been observed inside the open porosities of the carbon substrate which enhance the adhesion of the protection.The low pressure chemical vapor deposition (LPCVD) process developed here allows multilayer HfC/SiC depositions. The HfC coatings have various morphologies and thicknesses depending on the experimental conditions (temperature, pressure, dilution). This carbide has been firstly deposited over flat graphite substrates and carbon single fibers. Secondly, the multilayer coating deposition over a C/C composite and over carbon single fibersis studied. Finally, HfC layers have been infiltrated inside carbon fiber tows. To avoid the notch effect on the carbon fibers, a thin layer of pyrocarbon (50 nm thick) has been deposited prior to the growth of the carbides. All the coatings were done in a hot wall CVD reactor and their morphologies and chemical compositions characterized by scanning electron microscopy.