Design and evaluation of eco-engineered B4C/Fly ash composites: A green material for gamma and neutron shielding applications

Abstract

In this study, eco-engineered composite pellets made of fly ash and boron carbide (B₄C) are designed and evaluated for gamma-ray and neutron shielding applications. Composite samples with different B₄C ratios (0–75 wt%) have been prepared and examined using both theoretical and experimental methods. XRD and SEM are used for structural and morphological characterizations. A NaI(Tl) detector is used to measure gamma-ray attenuation parameters such as LAC, MAC, HVL, TVL, MFP, Zeff, and buildup factors. These values are further evaluated using Phy-X/PSD and GAMOS simulations. Values for the fast neutron removal cross-section (FNRCS) are also calculated. The composite with the most balanced performance is BCFA25, which has a compact microstructure and improved attenuation efficiency. Increasing the content of boron and carbon with lower atomic numbers increased neutron shielding but decreased Zeff and electron density. Strong agreement is found between theoretical models and experimental outcomes. The results indicate that B₄C/fly ash composites, especially BCFA25, offer a lead-free and sustainable option for radiation shielding in industrial, nuclear, and medical applications