LAUSR

Abstract The industrial development of dry storage method of spent nuclear fuels strongly requires the low-cost B4C–Al neutron absorber materials (NAMs) with high strength and high stability at elevated temperatures. In the present work, the B4C–6061Al composites were fabricated by powder metallurgy method with different hot-pressing temperatures. Microscopic analysis showed that as hot-pressing temperatures increased from 560 °C to 630 °C, the interfacial reactions became severe, resulting in the formation of Al3BC and Mg(Al)B2 compounds. The mechanical properties of the composites were enhanced by the interfacial reactions, specifically, the tensile strength of the sample hot-pressed at 630 °C was 40–59% higher than that at 560 °C at testing temperatures from room temperature up to 350 °C. Moreover, the high-temperature-pressed sample maintained the invariant strength level after suffering annealing at 400 °C for 8000 h. Characterization of the fractured composite indicated that the Mg(Al)B2 nanorods which effectively impeded the dislocation movement and grain boundary sliding provided a significant contribution to the composite strength.