Abstract: The flexural and compressive properties of PBO fiber and T700 carbon fiber hybrid composites were studied in this paper. The effects of hybrid ratio on flexural strength and modulus, compressive strength and modulus of hybrid composites were examined by a universal testing machine. Flexural and compressive failure mode of PBO/T700 hybrid composites was also discussed. The results indicate that the flexural strength and compressive strength of PBO fiber reinforced composite increased from 542MPa and 233.2MPa to 1120MPa and 702MPa after hybridization with T700 carbon fiber. The flexural and compressive failure mode of PBO fiber reinforced composite and T700 carbon fiber reinforced composite were typically ductile failure and brittle failure, respectively. The flexural and compressive failure mode PBO/T700 hybrid composites shift from ductile failure to brittle failure with increasing of the hybrid ratio.

Key words: PBO fiber, carbon fiber, hybrid composites, flexural properties, compressive properties