Elucidating the hydrogen-entry-obstruction mechanism of a newly developed aluminum-based coating in high-pressure gaseous hydrogen
Elucidating the hydrogen-entry-obstruction mechanism of a newly developed aluminum-based coating in high-pressure gaseous hydrogen
复制标题
DOI：
10.1016/j.ijhydene.2015.06.023
复制
发表时间：
2015-08
影响因子：
7.2
通讯作者：
J. Yamabe;Tohru Awane;S. Matsuoka
中科院分区：
文献类型：
--
作者：
J. Yamabe;Tohru Awane;S. Matsuoka
本研究提出了一种新型铝基三层(氧化铝/铝/铁铝)涂层在高压氢气中的精确阻氢机理。在高压气态氢中，溅射钯的铝基涂层的氢含量与铝基涂层的相同，但不含钯。此外，涂层样品的氢含量随着样品尺寸的减小而增加。这些结果表明，氢是通过扩散控制过程进入的。涂层试件的有效扩散系数约为母钢(304不锈钢)的千分之一。双层涂层(氧化铝/铝铁)无法获得如此优异的耐蚀性。用二次离子质谱仪对局部氢浓度的分析表明，三层涂层试件极低的有效氢扩散系数是由于铝-铁-铝界面处的氢捕获，而不是铝层对氢进入的阻碍。
This study presents a precise hydrogen-barrier mechanism of a newly developed three-layer (alumina/aluminum/ferro-aluminum) aluminum-based coating in high-pressure gaseous hydrogen. After exposure to high-pressure gaseous hydrogen, the hydrogen content of the specimen with a palladium-sputtered aluminum-based coating was the same as that of the specimen with aluminum-based coating, but without palladium. Furthermore, the hydrogen content of the coated specimens increased with a decrease in the specimen size. These results indicate that the hydrogen entered by a diffusion-controlled process. The effective diffusivity of the coated specimen was approximately one thousandth of that of base steel (type 304 stainless). Such excellent resistance could not be obtained with a two-layer coating (alumina/ferro-aluminum). Analysis of local hydrogen concentrations by secondary ion mass spectroscopy demonstrated that the extremely low effective hydrogen diffusivity of the three-layer-coated specimen was attributed to hydrogen trapping at the aluminum–ferro-aluminum interface, and not to the hydrogen-entry obstruction by the aluminum layer.