Microstructure and mechanical properties of B4C/6061Al neutron absorber composite tube fabricated by spark plasma sintering and hot spinning

Abstract In this study, a B4C/6061Al neutron absorber composite (NAC) tube containing 5 wt.% B4C particle was first fabricated by spark plasma sintering (SPS) followed by hot spinning (HS), then its microstructure and mechanical properties were experimentally investigated. It was found that, through spinning, B4C particles were better distributed in the 6061 Al matrix and the bonding of the B4C/6061Al matrix interface was improved. Dislocation pileups around B4C particles and dislocation loops were both observed. B4C particles could promote dynamic recrystallized nucleation and pin grain boundaries, resulting in grain refinement in the material. The yield strength (YS), ultimate tensile strength (UTS), and elongation of the spinned composite tube were found higher than that of the SPSed composite tube. The strength improvement of the fabricated B4C/6061Al neutron absorber composite tube was mainly due to the dislocation strengthening mechanism and grain refinement through spinning.