Synergistic enhancement of strength and neutron shielding capacity in B4C/Al composites using B4C nanoparticles

Despite their low density, good corrosion resistance, and thermal stability, aluminum matrix composites for radiation shielding materials have inadequate yield strength to meet the requirements of the aerospace and nuclear sectors. Therefore, this study aimed to simultaneously improve the mechanical strength and neutron shielding capacity by uniformly dispersing B 4 C nanoparticles in an Al matrix via powder metallurgy, offering advantages over conventional microscale B 4 C in both aspects. These enhancements principally originate from the unique fiber-like morphology and rolling-induced alignment of B 4 C nanoparticles. This structural configuration provides dual benefits: maximizing the geometric potential for load transfer to enhance mechanical properties and extending the neutron path length via geometric scattering effects for superior shielding. Incorporating B 4 C nanoparticles results in composites with a nanocrystalline matrix with a maximum hardness of 239.41 HV and an estimated yield strength of approximately 799 MPa—more than six times the mechanical performance of conventional systems containing microscale B 4 C particles. Simultaneously, neutron transmittance is significantly reduced to 0.77%, demonstrating a shielding efficiency exceeding 99%. These findings highlight the critical role of nanoscale dispersion in simultaneously optimizing structural and functional performance, offering a promising pathway for the development of lightweight, multifunctional composites for demanding applications in aerospace, defense, and nuclear technologies.