Study of hydrogen migration mechanisms in materials with complex crystal textures

复杂晶体结构材料中氢迁移机制的研究

基本信息

批准号：
12680502
负责人：
YAMAKAWA Kohji
金额：
$ 2.24万
依托单位：
Ehime University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12680502/
关键词：
Hydrogen Multi-layers Hydrogen permeation Hydrogen diffusion Surface 拡散表面状態

项目摘要

The hydrogen permeability measurements in Pd, Fe, Ni membranes have been done by the gas permeation method by an ultrahigh vacuum apparatus. The use of an ultrahigh vacuum apparatus enables us to measure at low pressure and temperature and at thin foil. It is shown that the hydrogen permeation through Pd membrane is exceedingly affected by the surface contamination of the specimen. The contaminants are taken off from the Pd surface by short aging at low temperatures. After this surface cleaning, the amount of hydrogen permeation increases and shows linear-like Arrhenius relation.From above results, our permeation method is suitable for hydrogen permeation experiment of multi-layers specimen. Therefore, the permeation of hydrogen is measured for various number of layers and thickness of multi-layers in Pd-Fe and Pd-Ni systems on Pd base plate.Even after cleaning the Pd surface, the amount of hydrogen permeation through Pd-Ni multi-layers does not show linear-like Arrhenius relation and is larger than that from model calculation in which the bulk property values of Ni are used. From the experimental results and model calculations, it is concluded that the permeation through Pd-Ni multi-layers is not affected by inter Pd layers and boundary layers. Enhanced hydrogen permeation is caused by high grain boundary permeation through small grained Ni layers.After cleaning the Pd surface, the permeation amount through Pd-Fe multi-layers showed linear-like Arrhenius relation, but the dependence for the thickness and number of Fe layers was complex. Further investigation must be needed for this system. The amount through Pd-Fe multi-layers decreased than those obtained from model calculation different from the case of Pd-Ni system.Surface analysis of Pd foil is done by Auger electron spectroscopy and hydrogen gas permeation through Pd is suppressed by C atoms which may come from hydrocarbons.

Pd、Fe、Ni 膜的氢渗透率测量是通过超高真空装置采用气体渗透法进行的。超高真空设备的使用使我们能够在低压和低温下以及薄箔上进行测量。结果表明，氢气通过 Pd 膜的渗透很大程度上受到样品表面污染的影响。通过低温下的短暂老化，污染物从钯表面去除。经过表面清洗后，氢渗透量增加，并呈现线性阿伦尼乌斯关系。从以上结果来看，我们的渗透方法适用于多层试件的氢渗透实验。因此，在 Pd 基板上的 Pd-Fe 和 Pd-Ni 系统中，测量不同层数和多层厚度的氢渗透量。即使在清洁 Pd 表面后，通过 Pd-Ni 多层膜的氢渗透量-layers 不表现出类似线性的阿伦尼乌斯关系，并且大于使用 Ni 的体属性值的模型计算的结果。从实验结果和模型计算可以看出，Pd-Ni多层膜的渗透不受Pd层间和边界层的影响。增强的氢渗透是由小晶粒 Ni 层的高晶界渗透引起的。清洁 Pd 表面后，Pd-Fe 多层的渗透量呈现线性阿伦尼乌斯关系，但与 Fe 层的厚度和数量有关很复杂。该系统还需要进一步调查。与 Pd-Ni 体系的情况不同，通过 Pd-Fe 多层的量比模型计算得到的量有所减少。 Pd 箔的表面分析是通过俄歇电子能谱进行的，氢气透过 Pd 的渗透受到 C 原子的抑制，这可能来自碳氢化合物。