Scale characterisation of an oxidised (Hf,Ti)C-SiC ultra-high temperature ceramic matrix composite

A hybrid carbide ultra-high temperature ceramics matrix [(Hf,Ti)C-SiC] reinforced with BN-coated carbon fibres was fabricated and tested for surface oxidation resistance. The UHTC composite showed an average mass ablation rate of 0.0014 g/s after exposure to a high heat flux (∼17 MW/cm2) oxyacetylene flame test 30 s above 2500 °C. cross-sectional profile the oxides scale formed characterised analysed. multicomponent; consisting Hf, Ti Si, as well HfTiO4 HfSiO4, which underwent phase separation immiscibility. Multiple glassy bubbles on due impediment escaping gases by layer outer scale. largest pores in that resisted rupture were dominant features outermost phase-separated layer. Phase top improves resistance rupture.