Manufacturing of porous boron steels potentially useful as nuclear materials

B4C is a good neutron absorber, commonly used together with light materials in panels. The objective of this work is to manufacture high boron steels, using B4C additions, through mechanical alloying and sintering, to get a material potentially useful for nuclear waste management. The porosity of the material can help to the removal of helium bubbles. Iron and B4C powders were mechanically alloyed for different times, following the process studying apparent density, morphology (SEM) and structure (XRD). Powder was uniaxially compacted and sintered at different conditions. Specimens were analysed by SEM and physical and mechanical properties were evaluated (density, dimensional change and bending strength). Microstructures are very different and therefore, they have different properties depending on sintering temperature. Although boride formation always takes place, only ferritic areas were found at 600degC, meanwhile ferritic and perlitic areas appeared at 900degC, and both of them disappeared at 1,200degC. (author)