Effect of material and processing parameters on fiber pinning effect and resultant interfacial bonding strength of CF/PEEK bilayer parts in overmolding process. (April 2022)

• Record Type: Journal Article
• Authors: Jiang, Wei; Chen, Cheng; Deng, Tianzhengxiong; Wang, Xukang; Huang, Zhigao; Zhou, Helezi; Zhou, Huamin
• Is Part Of: Polymer testing. Volume 108(2022)
• Publication Date: 2022-04
• Subjects: A.Short-fiber composites -- B. Interfacial strength -- C. Representative volume element (RVE) -- D.X-ray computed tomography -- E.Overmolding process; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2022.107509
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: The overmolding for thermoplastic composites is an integrated process that can manufacture multilayer parts with complex structures. However, the interfacial bonding strength between layers manufactured by different processes is weak. Here we study how material and process parameters affect the fiber pinning effect and thereby influence the interface binding strength of overmolded bilayer parts. The bilayer parts were prepared by overmolding the short-carbon-fiber-reinforced polyether-ether-ketone (SCF/PEEK) onto the hot-pressed woven-CF/PEEK (WCF/PEEK) laminates. An analytical model showed that the fiber pinning effect was dominated by the fiber content ( C f ), interfacial temperature ( T i ) and fiber orientation ( α xx ). The experimental results showed that a 32% increase in interlaminar shear strength (ILSS) of bilayer parts was achieved by regulating material and process parameters and optimizing the fiber pinning effect. The microstructural characterization shows that the T i dominates the degree of resin fusion near the interface and thereby affects the fiber pinning depth indirectly. The C f not only changes the amount of pinned fiber, but also affects α xx, which was confirmed by nano-CT scan. Highlights: The short-fiber pinning effect was founded in the overmolded hybrid interface. A theoretical model was established to describe the pinning effect on the ILSS. The pinning effect was affected by the short fiber content, fiber orientation, and interfacial temperature. The ILSS was greatly enhanced by the pinning effect at higher interfacial temperatures.