Mullite based oxidation protection for SiC–C/C composites in air at temperatures up to 1900 K

Microstructure and anti-oxidation property of Si–W–Cr coating for SiC coated carbon–carbon composites

“…WO 3 was not tested because of the volatilization and low content after oxidation at 1773 K for 51 h. The melt point of WO 3 is 1746 K and the volatilization of WO 3 is serious at high temperature. During the oxidation experiment at 1773 K, WO 3 and SiO 2 formed according to chemical reactions (6). Some liquid WO 3 could penetrate through cracks in the coating and prevent oxygen infiltration into C/C matrix.…”

“…SiO 2 film has very low oxygen permeability (10 −13 g/cm s at 1200 • C, 10 −11 g/cm s at 2200 • C) and can efficiently prevent oxygen from diffusing into C/C substrate [4][5][6]. However, the ceramic coating cannot be applied directly on the C/C surface, owing to the mismatch of coefficient of thermal expansion (CTE) between ceramics and C/C composites.…”

Effect of α-Al2O3 coatings on the mechanical properties of Ni/SiC composites prepared by electrodeposition

“…Although this layer protects the reinforcement, the small thickness of the layer, the stress due to the high-temperature procedure and the crystalline transition suffered by silica tend to break the coating [15]. Other coatings such as mullite and BN/Si 3 N 4 have also been fabricated by vapor deposition like PVD and CVD [16,17]. Nevertheless these processes are too expensive and complex for large-scale production.…”

A MoSi2–SiC–Si/MoSi2 COATING TO PROTECT CARBON/CARBON COMPOSITES AGAINST OXIDATION AT 1700°C

“…1 To prevent these composites from oxidation at high temperature, coating is a logical method. 2,3 Multi-phase coatings containing MoSi 2 have been proved to have excellent oxidation protective ability for C/C at 1500-1600 • C in air, such as Si-Mo coating, 4,5 SiC-MoSi 2 , 6 and Si-MoSi 2 . 7 However, few literatures have been published about the oxidation protective coating for C/C composites for long-term application above 1650 • C. In our previous work, MoSi 2 -SiC-Si coating prepared by pack cementation could effectively protect C/C composites at 1500 • C in air for 200 h. 8…”