Inhibition of the catalytic oxidation of carbon/carbon composite materials by an aluminophosphate coating

The oxidation protection property of an aluminophosphate coating used to increase the lifetime of C/C composite materials has been investigated. This coating has already shown its ability to limit the thermal oxidation at high temperatures of C/C materials and we demonstrate in this paper its capacity to inhibit the catalytic oxidation. This catalytic oxidation, induced at low temperature by alkali and alkaline-earth elements (Na, K, Ca), is a crucial issue for aeronautical applications of C/C composite materials because of the presence of these catalytic elements in de-icing solutions used in airports. In addition, new information about the structure of the coating, prepared through the thermal treatment of a commercial aluminium phosphate solution, has been derived from XRD and solid-state NMR investigations.