Acta Metallurgica Sinica (English Letters) ›› 2024, Vol. 37 ›› Issue (7): 1201-1214.DOI: 10.1007/s40195-024-01693-1

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Effect of Ball Milling Time on Microstructure and Hydrogen Storage Properties of Nd5Mg41Ni Alloy

Zeming Yuan1,2(), Chenxu Liu1, Xiaoming Li1, Yongqi Sui1, Zhonggang Han1, Tingting Zhai1, Dianchen Feng1, Yanghuan Zhang2   

  1. 1Instrumental Analysis Center, Inner Mongolia University of Science and Technology, Baotou 014010, China
    2Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081, China
  • Received:2023-12-23 Revised:2024-01-26 Accepted:2024-01-26 Online:2024-04-09 Published:2024-04-09
  • Contact: Zeming Yuan

Abstract:

Mg-based alloys must be dehydrogenated at high pressure and temperatures, limiting their practical application. In this paper, Nd5Mg41Ni alloy was prepared by vacuum melting, and the as-cast alloy was ball milled for 5 h, 10 h, 15 h, and 20 h. The effect of ball milling time on the microstructure and hydrogen storage properties of the alloy was systematically studied. The alloy comprises Nd5Mg41, NdMg12, NdMg3, and Mg2Ni phases. The Nd5Mg41Ni alloy milling for 10 h can reach 95% of the saturated hydrogen absorption at 553 K by 40 s, and the alloy can desorb hydrogen only by 20 min. The dehydrogenation activation energy is only 99.9 kJ/mol H2. Ball milling makes the alloy produce many nanocrystalline and amorphous structures. The nano-grain boundary provides a channel for the diffusion of hydrogen atoms, and the high energy at the grain boundary provides energy for the phase deformation nucleus. Ball milling leads to the refinement of alloy particles and shortens the diffusion distance of hydrogen atoms to the interior of alloy particles. Defects such as twins and dislocations generated by milling provide energy for the phase deformation nucleus during the hydrogen absorption and desorption.

Key words: Hydrogen storage materials, Magnesium-base alloy, Ball milling, Nanocrystal, Kinetics