(1. C/C Composite Research Center, Key Laboratory of Thermal Structural Composites, Northwestern Polytechnical University, Xin 710072, China ) (2. School of Materials, Henan University of Science and Technology, Luoyang 471023, China)
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DOI:
10.7502/j.issn.1674-3962.2013.06.06
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Abstract:
The compound coating composed of SiC/MoSi2-Si-Cr-B layer and phosphate爂lass outer layer was prepared on the surface of 2D carbon cloth laminated carbon/carbon composites by two-step pack cementation and slurry-sintering techniques. At 950℃, the anti-oxidation performance of coated samples was evaluated in free-state and states?with?different?deformations, respectively. In addition, thermal shock test was also conducted from 950℃ to room temperature. The phase composition and microstructure of the as-prepared coating were characterized by XRD and SEM. The results show that the coating exhibits favorable thermal shock resistance and anti-oxidation properties, with a negative weight loss rate at 950℃. The phosphate?glass will be melted into a viscous-flow state at 950℃. It could seal the cracks and holes, resulting in the improvement of the thermal shock and oxidation resistance of the compound coating. However, under the bending state, the oxidation weight loss rate increases with the increase of deformation. The deformation will reduce the protective effect of anti-oxidation coating to some extent, accelerating the oxidation failure of carbon/carbon composites