Hiroaki Takei

EB-Irradiation Induced Strengthening of Carbon Fiber Reinforced Thermoplastic Polymers

Carbon fiber reinforced polymers (CFRP), which are typical composite materials, and have been applied as light structural materials with high strength [1, 2]. The further strengthening has been always expected to develop high speed transports with small energy consumption. Although influences of electron beam (EB) irradiation with high energy on the fracture toughness of carbon cross of carbon fibers in thermo-hardened epoxy resin matrix (thermo-hardened CFRP) have been often reported [3], no one has succeeded the strengthening of CFRP irradiated by electron beam. On the other hand, the homogeneous low voltage electron beam irradiation (HLEBI) often induces not only the hardening, high wear resistance and sterilization for practical use of polymer, but also the mist resistance [4–6]. In addition, the irradiation has improved not only the bending fracture strain of carbon fiber [7, 8], but also the deformation resistivity, strength and fracture strain on static tensile test [9]. In our recent research, it has succeeded that the EB-irradiation also enhances the fracture stress and fracture strain of static bending test of thermo-hardened CFRP [10]. Furthermore, the improvement of impact value of thermo-hardened CFRP by EB-irradiation has been also reported to apply to high-speed transports [11]. However, the production rate of thermo-hardened CFRP has been serious problem in mass production.