SiC/Si-W-Mo coating for protection of C/C composites at 1873 K

Dangshe Hou, Kezhi Li, Hejun Li, Qiangang Fu, and Yulei Zhang National Key Laboratory of Thermostructure Composite Materials, Northwestern Polytechnical University, Xi’an 710072, China

摘 要：In order to prevent carbon/carbon composites from oxidation at 1873 K, an efficient oxidation protective SiC/Si-W-Mo coating was prepared by a two-step pack cementation technique. The microstructures and the phase composition of the as-received multi-coating were examined by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. It is seen that the compact multi-coating is composed of α-SiC, Si, and （WxMo1-x）Si2. Oxidation test shows that, after oxidation at 1873 K in air for 102 h and thermal cycling between 1873 K and room temperature for 10 times, the weight loss of the SiC/Si-W-Mo coated C/C composites is only 0.26%. The invalidation of the multi-coating is attributed to the formation of penetrable cracks in the coating.

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