含钆中子屏蔽材料的设计及其力学性能分析

设计了一种具有良好中子屏蔽能力、高强度及高韧性的新型中子屏蔽材料，用于吸收核电站乏燃料储存格架和乏燃料运输过程中的热中子辐射。材料通过蒙特卡罗粒子传输(输运）软件MCNP进行设计，并通过放电等离子烧结设备及热轧的方式制成了板材。MCNP模拟结果及材料热中子屏蔽测试结果表明：铝基Gd₂O₃复合材料的热中子屏蔽性能与铝基碳化硼相当。Gd₂O₃颗粒球磨后呈现μm、亚μm级甚至有些颗粒达到了nm级。随球磨时间的增加，材料的力学性能逐渐增强。X射线衍射检测发现了钆-铝合金相的生成。经TEM分析表明：材料的强化机制主要是位错强化和nm级Gd₂O₃颗粒的弥散强化，拉伸强度和伸长率分别达到了240 MPa和16%，其断口主要为韧性断裂。

Design and Mechanical Analysis of Gadolinium-containing Neutron Absorbing Material

A new type of neutron absorbing material with good neutron absorbing capacity, high strength and high toughness was designed to absorb thermal neutron radiation in the nuclear power plant spent fuel storage grid and spent fuel transportation. The material was designed by MCNP which was the Monte Carlo particle transport software, and the plate was prepared by spark plasma sintering equipment and hot rolling. The results of MCNP simulation and thermal neutron absorbing test show that the thermal neutron absorbing performance of Gd₂O₃/6061Al composite material is comparable to that of B₄C/6061Al composite material. After the different ball mill time, the microstructure of Gd₂O₃ particles is analyzed as micron level, and even some particles reach nanometer scale. The material strength increases with ball mill time. The phase of Gd-Al was detected by X-ray diffraction. The TEM analysis result shows that the strengthening mechanism of the materials is mainly dislocation strengthening and dispersion strengthening of Gd₂O₃ particle at nanometer level. The tensile strength and elongation reach 240 MPa and 16% respectively, and the fracture is mainly ductile fracture.