Failure behavior and performance analysis of hybrid-fiber reinforced PAEK composites at high temperature

The mechanical properties, microstructure morphology and failure behavior of hybrid fiber reinforced thermoplastic composites containing defects were studied for a coupled thermal and mechanical loading. The system investigated was a hybrid short-fiber composite of poly (aryl ether ketone) reinforced with 30wt% of aluminum fibers and 10wt% of carbon fibers. Fracture tests of specimens with different artificial defects, including notches and crack-like slots, subjected to thermal and mechanical loading, were carried out by using three-point short-beam bending tests. The effects of changing temperature on the mechanical strength of the composite are then discussed in detail, and the failure modes and corresponding morphology of broken samples are systematically characterized by SEM. Finally, the macroscopic and microscopic failure behavior and corresponding morphology of the composite under coupled thermal and applied loads were characterised on the basis of the experimental data. Results show that the effect of changing temperature greatly affects the macroscopic fracture mode, microscopic failure behavior, and rupture morphology of the composite along with its mechanical properties.