Ultrasonic‐assisted reinforcement and annealing treatment of additive manufacturing polyether‐ether‐ketone

Abstract Fused filament fabrication (FFF) printing had the advantages of simple structure, low cost, and simple process. As the requirement for high‐performance special engineering plastics was increasing progressively, FFF 3D printing technology with Polyether‐ether‐ketone (PEEK) as the typical material was also developing rapidly. It was worth noting that there were unavoidable defects caused by comprehensive factors of FFF 3D printing forming conditions and printing equipment. Therefore, the main aim of this study was to investigate the most reasonable composite post‐treatment process route between ultrasonic‐assisted reinforcement and annealing technology, with the overarching goal of improving the crystallinity, eliminating, and reducing the inevitable internal voids in the printing process, and enhancing the comprehensive mechanical properties. Our experiments showed that ultrasonic‐assisted reinforcement, annealing treatment, and the composite processes can improve the tensile properties of FFF printed PEEK samples. The composite process of ultrasonic‐assisted reinforcement followed by annealing treatment was the most suitable process route because it increased the maximum tensile yield strength by 7.5% to 86.5 ± 0.43 MPa and the crystallinity by 2.4%. Moreover, the porosity was reduced by 65.6% to 1.08 ± 0.12% compared to the original FFF printed samples. Therefore, our investigations on the composite post‐treatment technology of ultrasonic‐assisted reinforcement and annealing treatment had laid a theoretical foundation for its industrial application, which would have a great research significance and application value.