STUDIES PERTAINING TO HYDROGEN CAR DEVELOPMENT. PART A. THE KINETICS AND MECHANISM OF MAGNESIUM ALLOY-HYDRIDE FORMATION AND DISSOCIATION

The reaction between high-pressure hydrogen and Mg-10Al to form MgH2 in the range of 400 to 450 degrees C was found to be a diffusion-controlled process. Initially hydrogen dissolved rapidly into the metal particles, and MgH2 generally nucleated homogeneously as spherical particles. Growth of the particles was controlled by hydrogen diffusion in the metal and the kinetics followed the Johnson-Mehl relationship. The particles were readily hydrided to 7 w/o hydrogen and were found to exhibit very little fragmentation. Dehydriding followed the same rate law and was found to be complete in 90 minutes at 300 degrees C, these conditions being favorable for the use of this hydride in vehicles combusting hydrogen. The reaction involving Mg-25Ni resulted in two hydrides, MgH2 and Mg2NiH4, the former being more stable and forming first.

  • Corporate Authors:

    University of California, Los Angeles

    School of Architecture and Urban Planning
    Los Angeles, CA  USA  90024

    Department of Transportation

    1200 New Jersey Avenue, SE
    Washington, DC  USA  20590
  • Authors:
    • Douglass, D L
  • Publication Date: 1974-10

Media Info

  • Pagination: 42 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00091546
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: UCLA-ENG-7489-PTA Final Rpt.
  • Contract Numbers: DOT-OS-40011
  • Files: NTIS, TRIS, USDOT
  • Created Date: Aug 13 1975 12:00AM