相界面对Mg-Ni合金中氢扩散性能的影响及微观机制

项目名称： 相界面对Mg-Ni合金中氢扩散性能的影响及微观机制

项目编号： No.51471065

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 刘宝忠

作者单位： 河南理工大学

项目金额： 85万元

中文摘要： 镁基合金中氢扩散速率是决定其吸/放氢性能的关键因素之一。相界面作为氢扩散通道对合金中氢扩散速率有重要影响，但相界面影响合金中氢扩散的微观机制仍不清楚。本项目拟以Mg-x at.%Ni（x=12-15）合金为研究对象，采用高压技术制备Mg6Ni单相合金，调整热处理温度和时间控制析出相尺寸和相界面分数；研究相界面微观结构和相界面中氢扩散行为，分析相界面分数对合金中氢扩散速率的影响，探索相界面中氢扩散的微观机制；通过研究氢化过程中氢流量和合金中氢浓度不同时合金相界面中氢扩散速率变化，氢流量和氢浓度对相界面微观结构的影响以及氢致相界面变化与相界面本征结构的关系，揭示氢流量和氢浓度影响相界面中氢扩散性能的微观机理；从相界面分数、相界面中氢扩散性能及两者的关联性上澄清相界面对Mg-Ni合金中氢扩散性能的影响机制，为优化镁基合金中相界面的氢扩散通道作用，提高合金中氢扩散性能提供基础数据和理论指导。

中文关键词： 镁镍储氢合金；氢扩散；相界面；高压凝固；微观结构

英文摘要： Hydrogen diffusion rate is one of key factors that determine the hydrogen absorption/desorption performance of Mg-based hydrogen storage alloys. As hydrogen diffusion channels, phase interfaces play an important role on hydrogen diffusion rate in the Mg-based alloys. However, the mechanism of the effect of the phase interface on hydrogen diffusion in the Mg-based alloys is still unclear. In this proposal, we will select the Mg-x at.%Ni(x = 12-15) alloys as the research objective. A single Mg6Ni phase alloy will be first prepared through the unltrahigh pressure solidification technique. And then the Mg-Ni alloys with different dimension precipitates and different phase interface fractions will be obtained by tuning the termperature and the time during heat treatment. Microstructure of the phase interface and hydrogen diffusion behaviors in the phase interface will be systematically investigated. Effect of phase interface fraction on hydrogen diffusion rate in the alloys will be analyzed. Micro-mechanism of hydrogen diffusion in the phase interface will be explored. Furthermore, the variation of hydrogen diffusion rate in the phase interface, the effect of hydrogen flux and hydrogen amounts on the microstructure of the phase interface, as well as the relationship between the hydrogenation-induced microstrucure trasformation and the intrinsic microstructure of the phase interface will be also studied. The micro-mechanism through which both hydrogen flux in the hydrogenation and hydrogen amounts in the alloys affect hydrogen diffusion in the phase interface will be elucidated. Finally, the effect of the phase interface on hydrogen diffusion properties in the Mg-Ni alloys will be clarified according to the phase interface fraction, the hydrogen diffusion in the phase interface and the relationship between the phase interface fraction and the hydrogen diffusion in the phase interface, which will provide some fundmental data and theoretical implications for optimizing hydrogen diffusion channel function of the phase interface and improving hydrogen diffusion performances in the Mg-based hydrgoen storage alloys.

英文关键词： Mg-Ni hydrogen storage alloys;Hydrogen diffusion;Phase interface;unltrahigh pressure solidification;Microstructures