Radiation shielding properties of low-density Ti-based bulk metallic glass composites: a computational study

Abstract

Bulk metallic glasses (BMGs), a new class of structural and functional materials with unique physical and chemical features like high corrosion resistance, high yield strength, low elastic modulus, and transparency to visible light, indicate they could be potential shield against unwanted radiations. This study presents an attempt to investigate radiation shielding efficiencies of a few titanium (Ti)-based BMGs with low densities of range 4.43–5.15 g/cm3. Different shielding properties viz., attenuation coefficients (μ m and μ), half and tenth value layers (HVL and TVL), mean free path (λ), effective atomic number (Zeff), buildup factors (EBF and EABF), and fast neutron removal cross-section (Σ R ) were evaluated in 0.015 − 15 MeV energy range using Phy-X/PSD software. The interaction of charged particles (i.e., H1 and He+2 ions) with BMG samples was investigated in terms of mass stopping power (MSP) and projected range (PR) by deploying Monte Carlo-based SRIM software. The five-parametric geometric-progression (G-P) fitting method was employed to calculate EBF and EABF, whereas Zeff values were calculated through atomic to electronic cross-section ratio. Further, obtained results were compared with two conventional shielding materials: lead (Pb) and heavy concrete (StMg). We found that among 8 BMGs, sample Ti41.9Zr36.3V12.1Cu6.3Be3.4(S1) with the lowest Ti and highest Zr-composition by mass (41.9% and 36.3%, respectively) exhibited the best gamma-rays, fast neutrons, and H1/He+2 ions shielding characteristics with the highest μ m (0.02–15 MeV), μ (0.015−0.2 MeV), Zeff (0.015–0.06 MeV) and Σ R . These values were higher than that of StMg, but lower than those of Pb. Moreover, S1 exhibited the lowest values of HVL, TVL, and λ in 0.015 − 0.2 MeV region for gamma-rays and also has the lowest MSP and PR values for H1/He+2 ions. However, the lowest EBF and EABF values belonged to BMG S1 in intermediate energy region (0.1−2 MeV) only. But, the sample Ti90Al6V4(S7) was the worst among all BMGs and StMg. Thus, low-density Ti-based BMGs have better performances towards gamma-rays, fast neutrons, and H1/He+2 ions shielding and hence the potential to replace conventional StMgs and toxic Pb-based materials.