Oxidation and erosion resistance of MoSi2-CrSi2-Si/SiC coated C/C composites in static and aerodynamic oxidation environment

A MoSi2-CrSi2-Si multi-composition coating was prepared on the surface of SiC coated carbon/carbon (C/C) composites by pack cementation in argon The crystalline structure of the multi-composition coating was measured by X-ray diffraction The morphology and element distribution were analyzed by scanning electron microscopy and energy dispersive spectroscopy, respectively The isothermal oxidation and erosion resistance of the multi-layer coating were investigated in electrical furnace and high temperature wind tunnel, respectively These results indicated that the weight loss of the coated C/C composites was only 0 8% after oxidation in air at 1873 K for 500 h, and the sample was fractured after erosion at 1873 K for 32 h in wind tunnel The weight loss of the coated C/C composites was considered due to the excessive depletion of the outer coating and the appearance of defects in the coating The mismatch of thermal expansion coefficient between the multi-layer coating and C/C composites caused excessive local stress and resulted in the ;fracture of the coated C/C composites (C) 2010 Elsevier Ltd All rights reserved