Development of Al-20Sm 2 O 3 -W Composites with Enhanced Gamma-Ray and Neutron Shielding, Mechanical and Corrosion Resistance

This study systematically investigates the microstructural, mechanical, and radiation protection properties of Al-Sm2O3-W composites. Samples containing different weight ratios of W were fabricated by mechanical milling and sintering, and their characterizations were carried out comprehensively. Increasing W content significantly increased the composites’ relative density and hardness; the 7W composite showed the most balanced mechanical performance, with a relative density of 91.52% and a hardness of 187.7 HV. However, the microstructural homogeneity decreased, and the relative density decreased slightly due to the agglomeration of Sm2O3 particles in the 9W additive. As a result of potentiodynamic polarization tests, it was determined that the corrosion resistance increased up to 7W but decreased again in the 9W composite due to increased porosity and microgalvanic cell formation. Neutron attenuation analysis showed that the attenuation ratios for thermal neutrons decreased with W content, while only a limited improvement was achieved against fast neutrons. In contrast, the attenuation performance against gamma photons with an energy of 0.661 MeV increased significantly with W content. A decrease in half-value layer and mean free path values supported increased parameters such as effective atomic number (Zeff), mass attenuation coefficient, and fast neutron removal cross section. The results reveal that Al-Sm2O3-W composites can be considered shielding materials that are particularly effective against gamma radiation and are mechanically robust and durable.