Mechanical performance of biomimetic Cf/ZrB2-SiC composites with a Bouligand structure

This study presents a novel fabrication strategy for unidirectional carbon fiber/ceramic films and integrates them with helical assembly, compression molding, and precursor infiltration and pyrolysis to construct a biomimetic Bouligand structure in ZrB 2 -SiC based composites. With a fixed helix angle of 30°, the influence of carbon fiber volume fractions (20 %, 30 %, 40 %) on the mechanical properties was investigated. The C f /ZrB 2 -SiC composites with 40 vol% carbon fiber exhibited the highest mechanical properties. Building upon this result, the effect of different helix angles (15°, 30°, 45°, 60°) on the mechanical properties was further investigated. The C f /ZrB 2 -SiC composite with 40 vol% fiber and a 60° helix angle sample exhibited the best overall mechanical performance, characterized by a flexural strength of 346.9 MPa, fracture toughness of 11.8 MPa·m 1/2 , and work of fracture of 5170.6 J·m −2 . SEM and CT analysis revealed that toughening was primarily attributed to crack deflection, microcracking, fiber pull-out, and bridging mechanisms.