Radiation shielding performance and microstructural characterization of Al–Cu-Sc/B4C nanocomposites

This study investigates the gamma-ray and fast-neutron shielding performance of Al–Cu–Sc/B4C nanocomposites containing 0–20 wt% boron carbide (B4C). The composites were produced using melt spinning, high-energy ball milling, and vacuum sintering techniques. Their structural and microstructural characteristics were examined by X-ray diffraction and scanning electron microscopy. Gamma-ray attenuation properties were measured experimentally at photon energies of 0.662, 1.173, and 1.333 MeV using a high-purity germanium detector. In addition, theoretical calculations were carried out in the 0.05–2.50 MeV energy range using Monte Carlo simulations together with the Phy-X/PSD calculation platform. Several radiation shielding parameters were evaluated, including the mass attenuation coefficient, half-value layer, mean free path, radiation protection efficiency, effective atomic number, and fast-neutron removal cross-section. The results show that the incorporation of B4C improves the fast-neutron shielding capability of the composites. The sample containing 20 wt% B4C exhibits an increase of approximately 32% in fast-neutron removal cross-section compared with the reference alloy. A slight reduction in gamma-ray attenuation is observed at low photon energy, whereas the shielding performance at medium and high energies remains nearly unchanged. These findings indicate that Al–Cu–Sc/B4C nanocomposites are promising lightweight and lead-free candidates for shielding against mixed gamma and neutron radiation. Their low density and the absence of toxic lead support potential applications in medical radiation facilities, nuclear technology systems, aerospace platforms, and industrial radiation environments where both radiation protection and weight reduction are important.