Structure and properties of Ni coated B 4 C/PbSb 8 shielding composite

Abstract

A new style Ni coated B₄C/PbSb₈ (Sb: 8 wt-%) shielding composite was prepared by hot pressing process. The microstructure, mechanical properties and radiation shielding effectiveness for high speed neutron, thermal neutron and γ ray were investigated and analysed. The results obtained reveal that good consistency between Ni coated B₄C and PbSb₈ alloy was obtained after a Ni coating was deposited on the surface of B₄C by PVD technique; the mechanical properties were excellent when the proportion of Ni coated B₄C is 30 vol.-%, and the tensile strength and hardness are 48·2 MPa and HB(22·13 g) respectively. Furthermore, the composite has satisfactory synthetical shielding effectiveness, especially the absorption ratio for thermal neutron which reaches the value of 97·4% at the thickness of 25 mm. The Ni coated B₄C/Pb–Sb shielding composite alleviates the conflict to a certain extent between synthetical shielding effectiveness and other performances such as mechanical properties and thermal stability.