硼酸镁晶须的制备及其中子辐射屏蔽性能

采用高温固相法制备硼酸镁晶须的最佳工艺条件为：焙烧温度大于900℃,焙烧时间为8.0 h.制得的晶须粗细均匀,晶型完美,直径约为1.5μm,长度约35μm,长径比约为24.经XRD、SEM和FT-IR分析确定为硼酸镁晶须.以酚醛树脂为基体,添加硼酸镁晶须制备硼酸镁晶须/酚醛树脂复合材料,探讨了硼酸镁晶须添加量和材料厚度对热中子屏蔽率的影响;当硼酸镁晶须添加量为40份时,热中子屏蔽率为73.64%,继续增加添加量,热中子屏蔽率增幅不大;材料厚度为1.0 cm时,热中子屏蔽率为85.01%,继续增加厚度,热中子屏蔽率增加不明显.实验结果表明,以硼酸镁晶须制备聚合物中子屏蔽材料不仅可行,而且对热中子辐射具有较好的屏蔽性能.

Preparation of magnesium borate whisker and its neutron radiation shielding performance

Magnesium borate whisker was made by high - temperature solid - phase method. The best preparation condition of magnesium borate whisker was obtained： roasting temperature was above 900℃, roasting time was 8.0 h. The diameter ofMg2B20s whisker was about 1.5 p,m, the length was about 35 i.tm, aspect ratio was about 24. The product was proved to be magnesium borate whisker by XRD, SEM and FT - IP-. A composite material was prepared by magnesium borate whisker and PF as substrate material. The relationships of thermal neutron shielding ratio between content of the whisker and thickness of the material was investigated. When the content of the whisker is 40 shares, the thermal neutron shielding ratio was 73.64% ; when the whisker was increased, the shielding ratio was not obviously improved. When the thickness of the material was 1.0 cm, the thermal neutron shielding ratio was 85.01% ; when the thickness was increased, the increment of the shielding ratio was not obvious. The experimental results show that preparation of the neutron shielding composite materials with magnesium borate whisker is not only feasible, but also it has a good thermal neutron radiation shielding performance.