B对Pb-Mg-Al-B屏蔽功能材料的显微组织与屏蔽性能的影响

利用立式高频感应炉制备出铸造Pb-Mg-Al-B屏蔽材料,并对其显微组织和屏蔽性能进行了研究。结果表明,随着B的添加,材料组织中AlB2颗粒增多;室温抗拉强度可达105MPa,布氏硬度为160;厚度为20mm、B含量为2.0%(质量分数)的Pb-Mg-Al-B屏蔽材料对能量为250、118和65keV的X射线屏蔽率分别为90.29%、99.22%和97.9%,对γ射线的屏蔽率达到49.75%(137Cs源)和34.21%(60Co源),对中子的屏蔽率高达92.7%,说明屏蔽材料具有强度高、X(γ)射线与中子屏蔽性能优异,具备结构-功能(屏蔽)一体化的特点。

Effects of B on microstructure and shielding properties of Pb-Mg-Al-B shielding functional materials

The cast Pb-Mg-Al-B shielding materials were prepared by using of vertical high-frequency induction furnace,and their microstructures,mechanical and shielding properties were investigated.The results showed that the AlB2 particles in the alloys increased with the addition of B.The room temperature tensile strength and Brinell hardness were up to 105MPa and 160,respectively.The shielding rates of Pb-Mg-Al-2%B(mass percentage) shielding materials in thickness of 20mm were 90.29%,99.22% and 97.9% for X-ray with energies of 250,118 and 65keV;49.75%(137Cs source) and 34.21%(60Co source) for γ-ray;and 92.7% for neutron.It indicated that the shielding material possessed higher strength,excellent X(γ)-ray and neutron shielding properties,and had the features of the integration of structure-function(shield).