Achieving the synergy of superior damage tolerance and oxidation resistance of 2D C_f/ZrB₂-SiC composites via fiber heat treatment

The need for synergy of strengthening and anti-oxidation under high-temperature and oxidative environment imposes new demands on nonablative thermal protection materials. Herein, 2D C_f/ZrB₂-SiC composite with superior damage tolerance and excellent oxidation resistance were constructed using a simple fiber heat treatment. An enhanced flexural strength of 234 ± 18 MPa and an intermediate work of fracture of 1342 J/m² were obtained for 2D C_f-HT/ZrB₂-SiC composite, increasing by nearly 19.4% and 171.7% as compared with those of C_f-AR/ZrB₂-SiC sample, triggered by multiple toughening mechanisms including crack bifurcation, fiber bundles pull-out and bridging. The surface of 2D C_f-HT/ZrB₂-SiC composite was covered with a dense silica glass layer and embedded with a few zirconia particles after oxidation at 1500 °C for 1 h, resulting in an excellent oxidation resistance. This work presents a simple approach to achieve the synergy of superior damage tolerance and oxidation resistance of continuous carbon fiber reinforced ceramic matrix composite.