Boride and carbide coatings by plasma spraying – manufacturing and assessment at temperatures higher than 2000 K

Space applications involving atmospheric reentry impose high challenges to materials. Due to high velocity, materials will see temperatures higher than 2000 K, during several minutes in an oxidant atmosphere. Thermostructural composites such as carbon/carbon composites are good candidates to answer to this application. Nevertheless, these thermostructural materials meet oxidation problem at such level of temperature and need a protective layer. Ultra high temperature ceramic coatings applied by plasma spraying are a solution to protect composites from oxidation.

This study deals with the manufacturing of boride and carbide coatings by inert atmosphere plasma spraying on carbon/carbon composite and the assessment of their behavior at temperatures higher than 2000 K. Coatings were evaluated in low-pressure atmosphere under an oxidizing plasma jet with Vulcain set-up. Different oxidation mechanisms will be discussed based on SEM, XRD, EDS and SXES analyses.