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《机械工程前沿(英文)》 >> 2011年 第6卷 第4期 doi: 10.1007/s11465-011-0241-z
Development of oxide based diffusion barrier coatings for CFC components applied in modern furnaces
Surface Engineering Institute, RWTH Aachen University, 52072 Aachen, Germany
摘要
Carbon fibre reinforced carbon (CFC) materials show a high potential for usage in furnaces as sample carriers for example, which is due to their excellent thermal stability compared to steel carriers. Only their tendency to react with different metals at high temperatures by C-diffusion is a disadvantage, which can be solved by application of diffusion barriers. In order to enable the utilization of CFC-carriers for e.g. brazing furnaces, within the frame of this study thermally sprayed diffusion barrier coatings were developed. Coatings of mullite and ZrO2-7%βY2O3 (YSZ) were prepared by air plasma spraying (APS). The coatings were investigated in terms of their microstructure and thermal shock behaviour. In order to prove the suitability of the coatings for the application in brazing furnaces, the wettability of the coating surfaces by a Ni-based brazing alloy was investigated. The results showed that both mullite and YSZ could be deposited on CFC substrates with a bond coat of W or SiC. Both coatings exhibited good thermal shock behaviour and an excellent non-wetting behaviour against the used Ni-based braze alloy.
关键词
diffusion barrier coatings ; carbon fibre reinforced carbon (CFC) ; plasma spraying ; microstructure ; furnace
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