Mechanical and thermal neutron absorbing properties of b4 c/aluminum alloy composites fabricated by stir casting and hot rolling process

Abstract

In this study, to fabricate neutron shielding material, boron carbide (B4 C)-reinforced aluminum (Al) alloy composites were successfully fabricated by stir casting followed by a hot rolling process. Microstructural analysis of B4 C/Al6061 composites with different volume fractions (5, 10, 20, 25, and 30%) revealed that the composites had volume ratios similar to the target volume ratios of B4 C. Furthermore, B4 C reinforcements were uniformly dispersed in the Al matrix, forming multi-interfacial layers of Al4 C3 /(Ti,Cr)B2. The interfacial layer generated during stir casting maintained its own structure after the hot rolling process, indicating strong interfacial bonding strength. The tensile strengths of the B4 C/Al6061 composites increased to 20 vol.% and stayed above the value for Al6061, even reaching 30 vol.%. The measured thermal neutron shielding rate increased with increasing B4 C content, and the highest thermal neutron shielding rate was observed at 30 vol.% composite, which corresponds to 95.6% neutron shielding at 0.158-cm thickness.