Zr-Ni非晶态合金最大储氢量的计算

Calculation of the Maximum Hydrogen Capacity of the Amorphous Alloy Zr-Ni

根据非晶态合金的菱面体单元结构模型，结合氢在Zr－Ni非晶态合金中存在于3ZrlNi及4Zr4面体间隙的实验结果，通过计算每个菱面体单元中符合要求的4面体数的方法，计算出各种不同Zr含量时，Zr－Ni非晶态合金在Zr原子高度聚集态及Zr原子均匀分布态的氢含量，并描绘出2种极端状态下的最大储氢量MHmax及MH0随合金成分的变化曲线。结果发现：Zr－Ni非晶态合金的实际储氢量落在2条计算曲线之间，说明计算曲线是合理的，并从理论上解释了储氢合金产生成分偏聚的原因；非晶态Zr75Ni25合金具有最大的储氢量，理论储氢量可达2．0（H／M）。

In order to design an amorphous hydrogen storage alloy efficiently, the maximum hydrogen capacity of the amorphous alloy Zr-Ni has been calculated. Based on the Rhombic Unit Structure Model (RUSM) of the amorphous alloy, and the experimental result that hydrogen atoms exist in 3Zr1Ni and 4Zr tetrahedron interstices in the amorphous alloy Zr-Ni, the numbers of 3ZrlNi and 4Zr tetrahedron interstices in a RUSM, which correspond to the hydrogen capacity, have been calculated. Two extreme Zr distribution states (highly heterogeneous Zr distribution and homogeneous Zr distribution) have been calculated. The calculated curves of the hydrogen capacity with different Zr contents at two states indicate that the hydrogen capacity increases with the increase of Zr content and reaches the maximum at a Zr content of 75 at%, The theoretical maximum hydrogen capacity of the amorphous alloy Zr-Ni is 2.0 (H/M). The hydrogen capacity of heterogeneous Zr distribution alloy is higher than that of homogenous one for the same Zr content. The experimentally determined hydrogen capacity of the amorphous alloy Zr -- Ni lies between the two calculated curves, which proves that the calculated results reasonable. In this way the heterogeneous distribution of Zr atoms in amorphous alloy after a few hydrogen absorption-desorption cycles can be explained.Correspondent: Zhang Dongming, Associate Professor, State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P. R. China, Tel: 086-27-87884448