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摘要
针对传统中子吸收材料辐照肿胀、高温稳定性差等缺陷，本文以Dy₂(ZrₓTi₁₋ₓ) O₅（x=0、0.25、0.5、0.75、1）系列陶瓷为研究对象，采用高温固相反应法经二次烧结制备样品，系统探究Zr掺杂对材料晶体结构、热稳定性、热膨胀及力学性能的调控规律。结果表明：未掺杂Zr的Dy₂TiO₅难以形成纯净立方相，伴随杂相及烧绿石超晶格结构；低Zr掺杂（x=0.25）为烧绿石相，高Zr掺杂（x=0.5~1）可获得单相立方萤石结构。所制样品晶粒尺寸均匀（10~15 μm）、致密度高、元素分布均匀。600 ℃退火后物相仍能保持稳定，且含锆组分热匹配性更优。纳米压痕实验显示Dy₂ZrO₅硬度最高，综合性能优于Dy₂TiO₅。研究表明Dy₂ZrO₅具备优异的高温稳定性与力学性能，是新型控制棒中子吸收材料的理想候选材料，可为先进稀土基核用陶瓷的设计与应用提供实验支撑与理论参考。
Abstract
In response to the shortcomings of traditional neutron-absorbing materials, such as radiation swelling and poor high-temperature stability, this study focuses on the Dy2(ZrxTi1−x)O5 (x = 0, 0.25, 0.5, 0.75, 1) ceramic series. Samples were prepared using a high-temperature solid-state reaction method with secondary sintering, and the effects of Zr doping on the material’s crystal structure, thermal stability, thermal expansion, and mechanical properties were systematically investigated. The results show that Dy2TiO5 without Zr doping cannot form a pure cubic phase; instead, it exhibits impure phases and pyrochlore superstructure structures. Lower Zr doping (x = 0.25) results in a pyrochlore phase, while higher Zr doping (x=0.5 to 1) yields a single-phase cubic fluorite structure. The fabricated samples have uniform grain sizes (10–15 μm), high density, and evenly distributed elements. After annealing at 600°C, the phases remain stable, and the zirconium-containing components exhibit better thermal compatibility. Nanoindentation experiments indicate that Dy2ZrO5 has the highest hardness, outperforming Dy2TiO5 in terms of overall performance. The study demonstrates that Dy2ZrO5 possesses excellent high-temperature stability and mechanical properties, making it an ideal candidate material for new control rod neutron-absorbing materials. This research provides experimental support and theoretical references for the design and application of advanced rare earth-based nuclear ceramics.
| 关键词 | 中子吸收材料；锆掺杂；晶体结构；热稳定性；力学性能 |
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| Keywords | Neutron absorption material; Zirconium doping; Crystal structure; Thermal stability; Mechanical properties. |
