Journal Article

A New Strengthening Process for Carbon-Fiber-Reinforced Thermoplastic Polyphenylene Sulfide (CFRTP-PPS) Interlayered Composite by Electron Beam Irradiation to PPS Prior to Lamination Assembly and Hot Press

Eiichi Miura, Michelle Salvia, Helmut Takahiro Uchida, Keisuke Takeda, Yoshitake Nishi, Hideki Kimura, Michael C. Faudree, Kohei Sagawa

2023

Overview

Impact by hailstone, volcanic rock, bird strike, or also dropping tools can cause damage to aircraft materials. For maximum safety, the goal is to increase Charpy impact strength (auc) of a carbon-fiber-reinforced thermoplastic polyphenylene sulfide polymer (CFRTP-PPS) composite for potential application to commercial aircraft parts. The layup was three cross-weave CF plies alternating between four PPS plies, [PPS-CF-PPS-CF-PPS-CF-PPS], designated [PPS]4[CF]3. To strengthen, a new process for CFRP-PPS was employed applying homogeneous low voltage electron beam irradiation (HLEBI) to both sides of PPS plies prior to lamination assembly with untreated CF, followed by hot press under 4.0 MPa at 573 K for 8 min. Experimental results showed a 5 kGy HLEBI dose was at or near optimum, increasing auc at each accumulative probability, Pf. Optical microscopy of 5 kGy sample showed a reduction in main crack width with significantly reduced CF separation and pull-out; while, scanning electron microscopy (SEM) and electron dispersive X-ray (EDS) mapping showed PPS adhering to CF. Electron spin resonance (ESR) of a 5 kGy sample indicated lengthening of PPS chains as evidenced by a reduction in dangling bond peak. It Is assumed that 5 kGy HLEBI creates strong bonds at the interface while strengthening the PPS bulk. A model is proposed to illustrate the possible strengthening mechanism.

• Publisher: MDPI AG,MDPI
• Subject: Aircraft components / Aircraft construction materials / Aircraft parts / Assembly / Bird impact / Bird-aircraft collisions / Bonding strength / Carbon / Carbon fiber reinforced plastics / Climatic changes / Commercial aircraft / composite; thermoplastic; polyphenylene sulfide; carbon fiber; interlayered; electron beam; impact strength; electron spin resonance / Electron beams / Electron irradiation / Electron paramagnetic resonance / Electron spin / Energy consumption / Epoxy resins / Fiber reinforced polymers / High temperature / Impact strength / Innovations / Laminated materials / Laminates / Layers / Low voltage / Mechanical properties / Optical microscopy / Polyphenylene sulfides / Polyphenylene sulphide / Reduction / Shear strength / Spin resonance / Strengthening / Tensile strength / Thermoplastics