Hydriding properties of the heat-treated MgNi alloys with nanostructural designed multiphase

K. Yamamoto, S. Orimo, H. Fujii, Y. Kitano

Research output: Contribution to journalConference article

22 Citations (Scopus)

Abstract

The structural and hydriding properties have been investigated for the heat-treated MgNi alloys with nanoscale structure which consists of the Mg2Ni and MgNi2 phases. The alloys were fabricated by mechanical alloying (MA) and heat treatment (HT), the so called MA/HT method. For the as-alloyed amorphous MgNi (a-MgNi) alloy, the maximum hydrogen content reaches 1.72 mass% at 473 K. The hydride, however, gradually decomposes into Mg2NiH4 and MgNi2 phases during measurement of pressure-composition isotherm. In the case of nanoscaled crystalline Mg2Ni (c-Mg2Ni)+amorphous MgNi2 (a-MgNi2) multiphase alloy, the maximum hydrogen content reaches only 0.35 mass% at 473 K. No plateau-like behavior is observed in the desorption process. In the case of nanoscaled c-Mg2Ni+crystalline MgNi2 (c-MgNi2) multiphase alloy, the maximum hydrogen content reaches 1.45 mass% at 473 K. A well-defined plateau region is observed of nearly 0.012 MPa at 473 K in the desorption process. Therefore, it is concluded that the hydriding properties of the nanoscaled MgNi multiphase alloy will be strongly affected by not only the structural properties of the matrix surrounding the c-Mg2Ni grains precipitated but also by the accumulation/release of internal stress on the precipitation process.

Original languageEnglish
Pages (from-to)546-551
Number of pages6
JournalJournal of Alloys and Compounds
Volume293
DOIs
Publication statusPublished - 1999 Dec 20
Externally publishedYes
EventProceedings of the 1998 International Symposium on Metal-Hydrogen Systems - Fundamentals and Applications (MH98) - Hangzhou, China
Duration: 1998 Oct 41998 Oct 9

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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