Design of ( <scp> B ₄ C </scp>  +  <scp>WC</scp> )/Carbon Fiber Neutron‐γ Integrated Composite Shielding Material and Its Irradiation Resistance

ABSTRACT The inability to balance the structural mechanical properties, radiation shielding function, and weight of traditional shielding materials is an obstacle that limits their wide application. In this paper, (B 4 C + WC)/carbon fiber neutron‐γ integrated composite shielding material with good mechanical properties is designed and prepared to realize the lightweight of shielding material, and its irradiation resistance is investigated. First, the NSGA‐II non‐dominated sorting genetic algorithm is used to optimize the design of (B 4 C + WC)/carbon fiber composite shielding material. The sum of neutron and γ‐ray dose equivalent rate and weight of the composite shielding material are taken as the design objectives to obtain the Pareto optimal solution set satisfying the constraints. Secondly, the point close to the ideal point on the Pareto optimal solution set is selected as the composite shielding material design scheme. Carbon fiber–reinforced polymer (CFRP) containing B 4 C and WC shielding fillers is prepared by hot‐pressing tank molding process. Finally, the mechanical properties, thermal stability, and microstructure of CFRP before and after γ‐ray + neutron irradiation are studied. The results show that the tensile strength of CFRP with shielding fillers is better than that of 316 L stainless steel. After irradiation, the interfacial bonding properties of carbon fiber and resin are enhanced, and the CC bonds of CFRP break, generating new CO and CO bonds. Compared with the unirradiated samples, the strength, thermal stability and glass transition temperature of the irradiated CFRP are less changed, showing good irradiation resistance.