Nanocrystalline Mg and Mg alloy powders by hydriding-dehydriding processing

• Published in: Transactions of Nonferrous Metals Society of China Vol. 20; no. 7; pp. 1326 - 1330
• Main Author: 王辛 王珩 胡连喜 王尔德
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-07-2010; School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
• Subjects: Alloy powders; dehydriching; Grain size; hydriding; Hydrogen storage; hydrogen treatment; Magnesium; Magnesium base alloys; Mg alloy; nanocrystalline; Nanocrystals; Scanning electron microscopy; Vacuum annealing; X射线衍射分析; 合金粉末; 扫描电子显微镜; 氢处理; 纳米晶; 透射电子显微镜; hydriding; nanocrystalline; Mg; hydrogen treatment; Mg alloy; dehydriching
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(09)60299-5

The process of mechanically assisted hydriding and subsequent thermal dehydriding was proposed to produce nanocrystalline Mg and Mg alloy powders using pure Mg and Mg-5.5%Zn-0.6%Zr （mass fraction） （ZK60 Mg） alloy as the starting materal. The hydriding was achieved by room-temperature reaction milling in hydrogen. The dehydriding was carried out by vacuum annealing of the as-milled powders. The microstructure and morphology of both the as-milled and subsequently dehydrided powders were characterized by X-ray diffraction analysis （XRD）, transmission electron microscopy （TEM）, and scanning electron microscopy （SEM）, respectively. The results show that, by reaction milling in hydrogen, both Mg and ZK60 Mg alloy can be fully hydrided to form nanocrystalline MgH2 with an average grain size of 10 nm. After subsequent thermal dehydriding at 300 ℃, the MgH2 can be turned into Mg again, and the newly formed Mg grains are nanocrystallines, with an average grain size of 25 nm.