Materials Transactions Online

Materials Transactions, Vol.44 No.11 (2003) pp.2356-2362
© 2003 The Japan Institute of Metals

Structural Stability and Dehydrogenation of (MgH2+Al, Nb) Powder Mixtures during Mechanical Alloying

Congxiao Shang, Mohamed Bououdina and Zheng Xiao Guo

Department of Materials, Queen Mary, University of London, Mile End Road, London E1 4NS, UK.

High-energy ball milling of MgH2 with appropriate alloying elements is reported to improve the hydrogenation kinetics of MgH2 but the relevant information on dehydrogenation is scarce. Here, a systematic study was carried out to clarify the effects of two key alloying elements, Nb and Al, on the microstructure and the dehydrogenation behaviour of the MgH2. Intensive mechanical alloying was carried out to synthesise (MgH2 + M) powder mixtures (M=Nb, Al). XRD Rietveld analysis revealed the formation of a new bcc phase in the (MgH2+Nb) mixture and a (Al, Mg) solid solution in the (MgH2+Al) mixture. The amount of the newly formed phase in each case increased with milling time, while the level of Nb or Al decreases. SEM analysis of the milled powders showed the existence of nano-particles within 20 hours of milling. Thermogravimetry (TG) results showed that the mechanically alloyed (MgH2+Nb) mixture released about 3.9 mass% H2 and the milled (MgH2 + Al) about 5.4 mass% H2 at 300°C within 10 minutes, compared with only 1.5 mass% of the milled MgH2 powder and 1.0 mass% of the as-received MgH2 under the same conditions.

(Received 2003/3/17; Accepted 2003/9/29)

Keywords: mechanical alloying, magnesium hydride, hydrogen storage

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  1. G. Liang, J. Huot, S. Boily, A. Van Neste and R. Schulz: J. Alloys Comp. 292 (1999) 247-252.
  2. K. H. J. Buschow, P. C. P. Bouten and A. R. Miedema: Rep. Prog. Phys. 45(9) (1982) 937-1039.
  3. J.-L. Bobet, C. Even, Y. Nakamura, E. Akiba and B. Darriet: J. Alloys Comp. 298 (2000) 297-284.
  4. J.-L. Bobet, B. Chevalier and B. Darriet: Intermetallics 8 (2000) 359-363.
  5. Y. Chen: J. Alloys Comp. 266 (1998) 150-154.
  6. Dalin Sun, Hirotoshi Enoki, Franz Gingl and Etsuo Akiba: J. Alloys Comp. 285 (1999) 279-283.
  7. R. Schulz, J. Huot, G. Liang, S. Boily, G. Lalande, M. C. Denis and J. P. Dodelet: Mater. Sci. Eng. A 267 (1999) 240-245.
  8. A. Zaluska, L. Zaluska and J. O. Strom-Olsen: J. Alloys Comp. 288 (1999) 217-225.
  9. A. Y. Esayed and D. O. Northwood: Int. J. of Hydrogen Energy 17 (1992) 41-52.
  10. M. Bououdina and Z. X. Guo: Mater. Sci. Eng. A 332 (2002) 210-222.
  11. F. Izumi: The Riteveld method, ed. by R. A. Young, (Oxford University Press, 1993), Chapter 13, pp.~237-253.
  12. J. Rodriguez-Carvajal: Proceedings of the XVth Cong., Int. Union of Crystallography, Satellite meeting on powder diffraction, (Toulouse, 1990), pp.~127-133.
  13. R. A. Young: The Riteveld method, ed. by R. A. Young, (Oxford University Press, 1993), Chapter 1, pp.~1-38.
  14. R. J. Hill: The Riteveld method, ed. by R. A. Young, (Oxford University Press, 1993), Chapter 5, pp.~61-101.
  15. T. B. Massalski: Binary Alloy Phase Diagrams, 2nd Ed., CD-ROM, (ASM International, 1996).
  16. J. F. Pelletier, J. Huot, G. Sutton, R. Schulz, A. R. Sandy, L. B. Lurio and S. G. J. Mochrie: target="_blink">target="_blink">Phys. Rev. B 63 (2001) 052103.
  17. M. A. Pick and R. Bausch: J. Phys. F: Metal Phys. 6(10) (1976) 1751-1763.
  18. J.-P. Bastide, B. Bonnetot, J. M. Letoffe and P. Claudy: Mater. Res. Bull. 15 (1980) 1215-1224.
  19. L. M. Lityagina, T. I. Dyulleva, S. S. Kabalkina, T. N. Dimova and V. G. Losev: Geokhin 1 (1985) 118-120.
  20. J. Huot, G. Liang, S. Boily, A. Van Neste and R. Schulz: J. Alloys Comp. 293-295 (1999) 495-500.
  21. F. C. Gennari, F. J. Castro and G. Urretavizcaya: J. Alloys Comp. 321 (2001) 46-53.
  22. R. B. Von Dreele: Review in Mineralogy, Vol.~20, ``Modern Powder Diffraction'', ed. by D. L. Bish and J. E. Post, (Mineralogical Society of American, 1981), Chapter 11, pp.~333-369.


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