Akademik Veri Yönetim Sistemi
Journal of Alloys and Compounds, cilt.1072, 2026 (SCI-Expanded, Scopus)
In this study, the nuclear radiation shielding performance of HfTiAlCuNi-based high-entropy alloy (HEA) composites reinforced with 25 wt% WO₃, Er₂O₃, and Bi₂O₃ was systematically investigated. The composites were produced by mechanical alloying, and their structural and morphological properties were examined using XRD and SEM/EDX analyses. The results showed improved elemental homogeneity and a milling-induced transition from crystalline to amorphous structure. Gamma-ray attenuation measurements were performed using a high-resolution Ultra-Ge detector with a Ba-133 radioactive source at photon energies of 81, 160, 223, 302, 356, and 383 keV. The experimental linear attenuation coefficients were used to determine the mass attenuation coefficient and related shielding parameters, including half-value layer, effective atomic number, and electron density. Theoretical attenuation parameters and buildup factors were also obtained using the EpiXS program. The results demonstrated that oxide reinforcement improved the gamma-ray shielding performance of the base HEA, particularly at low photon energies. At 81 keV, the MAC increased from 3.401 cm²/g for the base HEA to 4.974 cm²/g for the WO₃-reinforced composite, corresponding to an enhancement of about 46%. The Er₂O₃- and Bi₂O₃-reinforced composites also showed improved MAC values of 3.578 and 3.413 cm²/g, respectively. The WO₃-reinforced sample exhibited the most effective photon attenuation behavior, with the highest effective atomic number and the lowest HVL, EBF, and EABF values among the investigated samples. Fast-neutron shielding performance was evaluated experimentally, while the macroscopic removal cross sections were calculated theoretically. The Er₂O₃- and Bi₂O₃-reinforced composites showed better fast-neutron attenuation than the base alloy. These findings indicate that oxide-reinforced HfTiAlCuNi high-entropy composites are promising candidates for advanced gamma-ray and neutron shielding applications.