Effect of SmB₆ Addition on Microstructure and Mechanical Properties of SmB₆-316L Neutron Shielding Material

In order to obtain a novel neutron shielding material with better mechanical properties, SmB₆-316L neutron shielding materials with 0.5wt%-4.0wt% SmB₆content were prepared by mechanical alloying and spark plasma sintering（SPS）. The microstructures of the samples were analyzed using SEM and EBSD, the elemental distribution of the precipitated phases in the samples was studied by EPMA and the effect of SmB₆addition on the tensile properties of the samples were explored. The results show that the precipitated phases in SmB₆-316L samples are mainly distributed at the grain boundaries and trigeminal grain boundaries, and its main components are the oxides of Sm, Si and Cr-B compounds. With the increase of SmB₆, the grain size of the sample decreases, the size and content of the precipitated phase increases. All the SmB₆-316L samples with different SmB₆contents are ductile fracture. With the increase of SmB₆content, the strength of the samples increase and the elongation decreases. Excessive addition of SmB₆increases the content and size of precipitated phases,resulting in a significant elongation reduction. When the contents of SmB₆are 1.0wt%-2.0wt%, the SmB₆-316L samples with good mechanical properties are obtained.