Investigation into forming yttria-stabilized zirconia/PEKK composite with superior mechanical and tribological properties

Poly (ether ketone ketone) (PEKK) is a high-performance thermalplastic polymer and has been employed for aerospace, chemical processing, and automotive industries. To expand its application range in high-demanding operational conditions, research into new PEKK composites with superior mechanical properties while maintaining super low coefficients of friction (COF) is of a current interest for both researchers and engineers. This study investigates the effects of yttria-stabilized zirconia (YSZ) reinforcement weight content in a thermal aging process on the microstructure, thermal, tribological, and mechanical properties of YSZ/PEKK composites. It is demonstrated that the developed YSZ/PEKK composite exhibited superior mechanical performance with an ultra-low COF value of 0.11-0.17, 22% increase in Shore (D) hardness, and a high elongation of 21% (4 times of the pristine PEKK). The reinforcement mechanism of the YSZ particles addition into the PEKK matrix was studied and clarified. The process-structure-property relationship was established. It is expected that YSZ/PEKK would be a candidate material withstanding harsh operating environments. • YSZ/PEKK composite effectively increases the mechanical properties • Thermal aging treatment increases crystallinity of PEKK and char yield of composite • YSZ/PEKK composite exhibited high toughness and large elongation • Shore (D) hardness of YSZ/PEKK reached 86.5 HD, a 22% increase