Study on the mechanical properties and gamma/neutron radiation shielding performance of SnBi/B4C composite materials

The development of multifunctional shielding materials has become a hot research topic with the increasing requirements for radiation protection materials in terms of performance, weight and non-toxicity. In this study, non-toxic SnBi/B4C composites with different B4C contents (0, 3, 6, 9, 12 and 15 wt%) were successfully prepared by powder metallurgy, and their mass attenuation coefficients, half-value layers, mean free paths, effective atomic numbers, and 0.025 eV thermal neutron shielding performance. The results show that B4C plays a key role in regulating the mechanical properties and thermal neutron shielding properties of SnBi/B4C composites. When the B4C content was 9 wt% (S3), the integrated mechanical properties of the composites were optimal, and the yield strength, tensile strength, and microhardness were enhanced by 31 %, 32 %, and 129 %, respectively, compared with those of the samples without B4C. The radiation shielding effect is remarkable, the gamma-ray shielding performance in the energy range of 0.03-0.08 MeV is better than that of Pb. Meanwhile, the S3 sample with only 3 mm thickness can shield 99.7 % of thermal neutrons, while the shielding rate of the S0 sample without B4C is only 5.2 %. Comprehensive analyses show that the SnBi/B4C composites are superior in terms of environmental protection, mechanical properties, gamma-ray and thermal neutron shielding, with lighter weight and safer use. This finding provides a theoretical basis for the selection of efficient, non-toxic and diverse radiation shielding materials for medical and other special environments.