J Mater Sci Technol ›› 2007, Vol. 23 ›› Issue (04): 559-562.

• Research Articles • Previous Articles     Next Articles

W-Mo-Si/SiC Oxidation Protective Coating for Carbon/Carbon Composites

Dangshe HOU, Kezhi LI, Hejun LI, Qiangang FU, Jian WEI, Yulei ZHANG   

  1. National Key Laboratory of Thermostructure Composite Materials, Northwestern Polytechnical University, Xi′an 710072, China
  • Received:2006-10-30 Revised:2007-01-26 Online:2007-07-28 Published:2009-10-10
  • Contact: kezhi LI

Abstract: A W-Mo-Si/SiC double-layer oxidation protective coating for carbon/carbon (C/C) composites was prepared by a two-step pack cementation technique. XRD (X-ray diffraction) and SEM (scanning electron microscopy) results show that the coating obtained by the first step pack cementation was a thin inner buffer layer of SiC with some cracks and pores, and a new phase of (WxMo1-x)Si2 appeared after the second step pack cementation. Oxidation test shows that, after oxidation in air at 1773 K for 175 h and thermal cycling between 1773 K and room temperature for 18 times, the weight loss of the W-Mo-Si/SiC coated C/C composites was only 2.06%. The oxidation protective failure of the W-Mo-Si/SiC coating was attributed to the formation of some penetrable cracks in the coating.

Key words: C/C composites, Coating, Microstructure, Oxidation