Enhancement in the microstructure and neutron shielding efficiency of sandwich type of 6061Al-B4C composite material via hot isostatic pressing

Sandwich type of 6061Al-B4C composite plates, which are used as a thermal neutron absorber for spent nuclear fuel pool storage rack, were fabricated using two different consolidation ways as sintering and hot isostatic pressing (HIP) processes and their thermal neutron shielding efficiency was investigated as a function of B4C concentration ranging from 0 to 40 wt.%. For this purpose, two respective inner core compaction parts of sintered and HIPped neutron absorbing composite materials were first produced and then cladded them between two outer plates by HIP process. The application of HIP process provided not only a lead of excellent interfacial adhesion due to the improved wettability but also an enhancement of thermal neutron shielding efficiency owing to the more uniform dispersion of B4C particles.