Wu Yin, Cao Yi, Wu Ying, Li Dichen
School of Aerospace Engineering, Xi'an Jiaotong University, 710049 Xi'an, China.
State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, 710049 Xi'an, China.
Materials (Basel). 2020 May 18;13(10):2314. doi: 10.3390/ma13102314.
Polyethylene is used as a traditional shielding material in the nuclear industry, but still suffers from low softening point, poor mechanical properties, and difficult machining. In this study, novel boron carbide polyether-ether-ketone (PEEK) composites with different mass ratios were prepared and tested as fast neutron absorbers. Next, shielding test pieces with low porosity were rapidly manufactured through the fused deposition modeling (FDM)-3D printing optimization process. The respective heat resistances, mechanical properties, and neutron shielding characteristics of as-obtained PEEK and boron carbide PEEK composites with different thicknesses were then evaluated. At load of 0.45 MPa, the heat deformation temperature of boron carbide PEEK increased with the boron carbide content. The heat deformation temperature of 30% wt. boron carbide PEEK was recorded as 308.4 °C. After heat treatment, both tensile strength and flexural strength of PEEK and PEEK composites rose by 40%-50% and 65%-78%, respectively. Moreover, the as-prepared composites showed excellent fast neutron shielding performances. For shielding test pieces with thicknesses between 40 mm and 100 mm, the neutron shielding rates exhibited exponential variation as a function of boron carbide content. The addition of 5%-15% boron carbide significantly changed the curvature of the shielding rate curve, suggesting an optimal amount of boron carbide. Meanwhile, the integrated shielding/structure may effectively shield neutron radiation, thereby ensuring optimal shielding performances. In sum, further optimization of the proposed process could achieve lightweight materials with less consumables and small volume.
聚乙烯在核工业中用作传统屏蔽材料，但仍存在软化点低、机械性能差和加工困难等问题。在本研究中，制备了不同质量比的新型碳化硼聚醚醚酮（PEEK）复合材料，并作为快中子吸收剂进行了测试。接下来，通过熔融沉积建模（FDM）-3D打印优化工艺快速制造了低孔隙率的屏蔽试件。然后评估了所得不同厚度的PEEK和碳化硼PEEK复合材料各自的耐热性、机械性能和中子屏蔽特性。在0.45MPa载荷下，碳化硼PEEK的热变形温度随碳化硼含量的增加而升高。30%重量比的碳化硼PEEK的热变形温度记录为308.4℃。热处理后，PEEK和PEEK复合材料的拉伸强度和弯曲强度分别提高了40%-50%和65%-78%。此外，所制备的复合材料表现出优异的快中子屏蔽性能。对于厚度在40mm至100mm之间的屏蔽试件，中子屏蔽率随碳化硼含量呈指数变化。添加5%-15%的碳化硼显著改变了屏蔽率曲线的曲率，表明存在碳化硼的最佳含量。同时，集成的屏蔽/结构可有效屏蔽中子辐射，从而确保最佳屏蔽性能。总之，对所提出的工艺进行进一步优化可以实现耗材少、体积小的轻质材料。
