Rolling compacted fabrication of carbon fiber reinforced ultra-high temperature ceramics with highly oriented architectures and exceptional mechanical feedback

Inspired by natural exoskeleton composites in arthropods consisting of regularly oriented fibrous chitin within continuous matrices, a novel rolling compacted method was developed to enable controlled orientation of carbon fibers in UHTCs. Using rolling compaction, carbon fibers were arranged in ZrC-SiC matrix along highly consistent direction, in which ceramic powders were uniformly introduced into intrafascicular and interfascicular spaces of fiber bundles. The fabricated C_f/ZrC-SiC composite revealed an extendedly graceful fracture pattern and stably impeded crack propagation with a flexural strength and fracture toughness at 227 ± 3 MPa and 5.46 ± 0.14 MPa m^1/2. An exceptional work of fracture of 3244 ± 76 J/m² was achieved, one order of magnitude higher than those of UHTCs, attributed to toughening mechanism of oriented carbon fibers such as fiber pull-out and bridging accompanied by crack deflection and termination. This work provides an easily feasible way to tailor mechanical performance for fiber-reinforced composites through site-specific optimization of fiber orientation.