Effect of neutron irradiation on the mechanical properties of graphite fiber-based composites

Polymer and carbon composite materials reinforced with K-1100 ultra-high modulus fibers were subject to testing of their radiation resistance. Mechanical tests have been carried out, prior and after neutron irradiation at a dose of 7.1×10¹⁷ n/cm² (E>0.5 MeV) for organic matrix composite and 7.3×10¹⁷ n/cm² (E>0.5 MeV) for carbon matrix composite, to assess the radiation resistance. Flexural strength, deformation at break, Young’s modulus and dimensional changes were measured. Microstructure of the composites before and after irradiation was analyzed. The results showed that neutron irradiation causes significant changes in mechanical properties of composites with organic and carbon matrix and a slight variation in their dimensions. Stronger effects in mechanical properties changes for composites with carbon matrix were observed.