International audienceUltra-High Temperature Ceramics having melting points above 3500 K and high thermal conductivities are envisaged to elaborate future receivers of concentration solar power plants. The high pressure and solar temperature reactor (Réacteur Hautes Pression et Température Solaire, REHPTS) at the focus of the Odeillo 5 kW solar furnace was used to investigate the oxidation of three carbides (ZrC/MoSi 2 , ZrC/TaSi 2 , HfC/MoSi 2) that could be candidate. The concentration of the additives (TaSi 2 or MoSi 2) was 20 v.% in each composition. Each sample was oxidized in static air (P = 87 kPa) during 20 minutes at 1800, 2000 and 2200 K. Experiments were filmed using a video camera and the gaseous phase was analyzed by mass spectrometry. Various characterizations have shown that the natures of the carbide and additive would affect the composition of the oxide layer and therefore the high-temperature behavior of the sample
