Zr1-xTixCo 贮氚合金的原位中子衍射实验研究

ZrCo alloy is a kind of hydrogen storage material with excellent performance. It has an important demand background in the field of energy and military. The disproportionation of ZrCo alloy at high temperature and the decrease of hydrogen storage performance are the key problems that restrict the large-scale application of the alloy. This project is based on the new model of full process design and research based on "theoretical prediction, preparation and synthesis, characterization evaluation and verification feedback". Using the first principle calculation of high throughput quantum mechanics, the Ti element doping calculation of ZrCo alloy is carried out and the influence of Ti doping on the resistance to disproportionation, antitoxicity and hydrogen storage properties of ZrCo alloys is studied. The modified alloy samples were prepared by vacuum magnetic levitation melting process. The structure of alloy phase and other microstructure information were analyzed qualitatively, the thermodynamic and kinetic properties of hydrogen absorption / desorption were systematically studied, and its anti disproportionation, antivirus and hydrogen storage properties were investigated, and the quantitative structure of neutron diffraction was used. The information of the phase content and phase structure of the modified alloy was measured accurately, and the occurrence mode of Ti in the lattice of ZrCo alloy was studied, and the micro mechanism of the modification of the ZrCo alloy was excavated by the doping of elements. The research results are expected to provide a theoretical basis for the modification and large-scale application of alloys.

ZrCo合金是一种性能优良的储氢材料，在能源和军事领域有着重要的需求背景，ZrCo合金高温下使用易发生歧化、贮氢性能下降是制约合金大规模应用的关键问题。本项目拟基于“理论预测→制备合成→表征评估→验证反馈”的材料全流程设计和研究新模式，应用高通量量子力学第一性原理计算，对ZrCo合金开展Ti元素掺杂计算，研究掺杂钛元素对ZrCo合金抗歧化、抗毒化、贮氢性能的影响规律；采用真空磁悬浮熔炼工艺制备改性后的合金样品，定性分析合金相结构和其他微观组织信息，开展吸/放氢热力学、动力学性能的系统研究，考察其抗歧化、抗毒化、贮氢性能；采用原位中子衍射分析技术，精确测定改性合金相含量、相结构等信息，研究Zr1-xTixCo中晶格中的赋存方式，挖掘Ti元素掺杂对ZrCo合金改性的微观作用机理。研究结果有望对合金的改性和大规模应用提供理论依据。

中文摘要：该工作从已知的抗歧化机理入手，开展对ZrCo合金进行掺杂改善其储放氢性能和抗歧化性能的研究，使ZrCo基合金可成功的应用于ITER乃至其他方面，这对于可控聚变能在各方面的发展具有重要的应用价值和科学意义。在实验方面，同时对ZrCo合金分别进行了Ti和Hf元素的高浓度梯度掺杂，采集储放氢动力学性能、热力学性能和抗歧化性能，增强说服力；而计算模拟方面，同时从ZrCo基合金晶格常数、Zr-H(8e)键长、8e-size、4c2-size、H(8e)领位原子占据情况和H(8e)占据率等因素着手，观察随着掺杂元素浓度的上升，各种因素对合金抗歧化性能的影响力大小，确定真正影响ZrCo合金抗歧化性能的重要因素；应用方面，以Zr0.8Ti0.2Co合金为例，经过元素掺杂后的ZrCo合金已经拥有了优秀的热力学性能，而其抗歧化性能也有了极大的提升，极大的增强了ZrCo合金成功应用的可能性。实验与模拟结果表明：（1）综合分析热力学，动力学及抗歧化性能后发现，在Zr1-xTixCo(X=0-0.5)系列合金中，Zr0.8Ti0.2Co合金是优秀的储氚合金。（2）H(8e)占据率和Zr-H(8e)的键长是影响ZrCo基合金的抗歧化性能的重要因素。（3）ZrCo 基合金发生氢致歧化时并不会出现H原子额外占据8e间隙位的情况，更多的仍是不饱和氢化物ZrCoH3-x中H原子从4c2间隙位扩散至8e间隙位。