Study on Hydrogen Absorption and Desorption Mechanisms in Nanostructured Alloys

纳米结构合金吸放氢机理研究

• 批准号: 17560588
• 负责人: TANAKA Kazuhide
• 金额: $ 2.24万
• 依托单位: TOYOTA PHYSICAL AND CHEMICAL RESEARCH INSTITUTE
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17560588/
• 关键词: Hydrogen absorbing materials; Mg-based alloys; Nano-structure; Melt-spinning; Thermal desorption spectroscopy; High-resolution electron microscopy; Hydrogen plasmon peak; Hydrogen desorption mechanism; Mg基合金; 溶融急漕法; 熱放出スペクトル; 水素顕微鏡; PCT特性; TD

We have previously found that, in Mg-based Mg-Ni and Mg-Ni-La alloys, the hydrogen absorption properties (PCT characteristics and kinetics) are significantly improved by nanostructure formation in the alloys. The objective of this research is to make clear the static properties of hydrogen present in the nano-structured alloys and to reveal the kinetics of hydrogen desorption from the alloys. To accomplish these purposes, we have carried out thermal desorption spectroscopy (TDS) measurements and high resolution transmission electron microscope (HRTEM) observation of alloy specimens prepared by melt-spinning and subsequent crystallization. They were hydrogenated ex-situ by reacting with H_2 gas of 1MPa at 300℃.In TDS measurements of hydrogenated alloys, four kinds of peaks (a〜d) are usually observed at temperatures between 200 and 350℃, and they are attributed to release of hydrogen from Mg_2NiH_4,MgH_2,nano-grain boundaries, and LaH_3 hydrides, respectively. By analyzing the TDS spectr … More a, the relative stability of hydrides characterized by the difference of hydrogen potential has been determined.In the HRTEM observation of the hydrogenated alloys, spherical nano-sized (5-10nm) grains of Mg_2NiH_4 and LaH_3 hydrides are usually observed, imbedded homogeneously in MgH_2 nano-grain matrices. After dehydrogenation at 300℃, the LaH_3 nano-grains are still remaining together with nano-sized Mg_2Ni grains imbedded in the Mg nano-grain matrices. This result indicates that the nanostructures formed in these Mg-based alloys are rather stable to both thermal cycling and hydrogenation-dehydrogenation treatments. The enhanced desorption rate of hydrogen in nano-structured alloys is possibly attributed to quick diffusion of hydrogen atoms along nano-grain boundaries toward the alloy surfaces.In addition to these HRTEM observations, we have first succeeded in visualizing the hydrogen distribution in the specimen by EELS mapping of an H-plasmon peak. The thermal desorption process of hydrogen has successfully been observed in-situ in the electron microscope. This technique is expected to develop as a powerful tool for detecting the dynamic behavior of hydrogen in metallic materials. Less

我们先前已经发现，在镁基Mg-Ni和Mg-Ni-La合金中，通过在合金中形成纳米结构，氢吸收性能（PCT特性和动力学）显著改善。本研究的目的是弄清氢在纳米结构合金中的静态性质，并揭示氢从合金中脱附的动力学。为了实现这些目的，我们已经进行了热脱附光谱（TDS）的测量和高分辨率透射电子显微镜（HRTEM）观察合金试样制备的熔体旋转和随后的结晶。在氢化合金的TDS测试中，在200 ~ 350 ℃范围内，通常观察到四种不同的峰（α d），它们分别是Mg_2NiH_4、MgH_2、纳米晶界和LaH_3晶界的氢释放。通过对TDS的分析， ...更多信息 在氢化合金的HRTEM观察中，通常观察到Mg_2NiH_4和LaH_3纳米晶的球形纳米尺寸（5- 10 nm）均匀地嵌入MgH_2纳米晶基体中。在300℃脱氢后，LaH_3纳米颗粒和Mg_2Ni纳米颗粒仍然存在于Mg纳米颗粒基体中。这一结果表明，在这些镁基合金中形成的纳米结构对热循环和氢化-脱氢处理都相当稳定。氢在纳米结构合金中的增强的脱附速率可能归因于氢原子沿沿着纳米晶界向合金表面的快速扩散。除了这些HRTEM观察，我们首次成功地通过EELS映射的H-等离子体峰可视化试样中的氢分布。在电子显微镜上成功地原位观察了氢的热脱附过程。该技术有望发展成为检测金属材料中氢的动态行为的有力工具。少

项目成果

Analysis of hydrogen distribution on Mg-Ni alloy surface by scanning electron-stimulated desorption ion microscope(SESDIM)

扫描电子刺激解吸离子显微镜(SESDIM)分析Mg-Ni合金表面氢分布

• 期刊: Journal of Alloys ＆ Compounds (投稿中)
• 作者: 山田正明;日比野清秀;鈴木正則;田中一英;山賀敦司;上田一之;Atsushi Yamaga
• 通讯作者: Atsushi Yamaga

Hydride stability and hydrogen desorption characteristics in melt-spun and nanocrystallized Mg-N-La alloy

熔纺纳米晶 Mg-N-La 合金的氢化物稳定性和氢解吸特性

• 发表时间: 2007
• 期刊: J.Alloys Compds. (in press)
• 作者: G.Piao;F.Kimura;T.Takahashi;Y.Moritani;H.Awano;S.Nimori;K.Tsuda;K.Yonetake;T.Kimura;Kazuhide Tanaka;Kazuhide Tanaka;Atsushi Yamaga;田中一英;K.Tanaka
• 通讯作者: K.Tanaka

Hydrogen Absorbing and Desorbing Properties and Their Mechanisms in Nanostructured Mg-Based Alloys Prepared by Rapid Quenching (in Japanese)

快速淬火制备纳米镁基合金的吸放氢性能及其机制（日文）

• 发表时间: 2006
• 期刊: Reports of Toyota Physical and Chemical Research Institute No.59
• 作者: A.Yamaga;M.Yamada;K.Hibino;M.Suzuki;Tanaka;K.Ueda;K.Tanaka;Kazuhide Tanaka;田中 一英;田中一英;K.Tanaka
• 通讯作者: K.Tanaka

Analysis of Hydrogen Distribution on Mg-Ni Alloy Surface by Scanning Electron-Stimulated Desorption Ion Microscope

扫描电子刺激解吸离子显微镜分析镁镍合金表面氢分布

• 发表时间: 2007
• 期刊: Journal of Alloys and Compounds (印刷中)
• 作者: G.Piao;F.Kimura;T.Takahashi;Y.Moritani;H.Awano;S.Nimori;K.Tsuda;K.Yonetake;T.Kimura;Kazuhide Tanaka;Kazuhide Tanaka;Atsushi Yamaga
• 通讯作者: Atsushi Yamaga

Hydride Stability and Hydrogen Desorption Mechanism in Magnesium-Based Nanostructured Alloys (in Japanese)

镁基纳米结构合金中的氢化物稳定性和氢解吸机制（日文）

• 发表时间: 2007
• 期刊: Reports of Toyota Physical and Chemical Research Institute No.60
• 作者: A.Yamaga;M.Yamada;K.Hibino;M.Suzuki;Tanaka;K.Ueda;K.Tanaka
• 通讯作者: K.Tanaka