Gamma and X-ray radiation shielding of the Ta-Ti-V-W high-entropy alloy: A combined experimental and theoretical study

High-entropy alloys (HEAs) are a promising class of materials for applications requiring both structural robustness and radiation resistance. In this work, we investigate the gamma and X-ray attenuation properties of the Ta-Ti-V-W high-entropy alloy, combining theoretical predictions with experimental validation. Mass attenuation coefficients calculated using the XCOM model indicate that the Ta-Ti-V-W alloy exhibits photon-shielding efficiency comparable to that of lead, particularly in the energy range of 0.6–7 MeV, which is relevant for medical, industrial, and nuclear applications. Experimental measurements using Cs-137 and I-131 sources confirm that the alloy’s attenuation performance closely follows theoretical predictions, with near-lead equivalence observed for Cs-137. Microstructural characterization revealed a dendritic microstructure with moderate elemental segregation, and no phase changes were observed upon gamma exposure. First-principles density functional theory (DFT) calculations indicate a complex electronic structure with a notable covalent contribution due to transition metal d-orbital hybridisation effect, which may potentially enhance photon–electron interactions in the alloy. The combination of excellent radiation shielding, phase stability, and superior mechanical properties establishes Ta-Ti-V-W as a strong lead-free candidate for multifunctional applications in space, nuclear, and radiological technologies.