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.
University of California, Los AngelesSchool of Architecture and Urban Planning
Los Angeles, CA USA 90024
Department of Transportation1200 New Jersey Avenue, SE
Washington, DC USA 20590
- Douglass, D L
- Publication Date: 1974-10
- Pagination: 42 p.
- TRT Terms: Automobiles; Chemical reactions; Crystallization; Diffusion (Optics); Fuel storage; Fuels; Hydrides; Hydrogen; Inorganic compounds; Kinetics; Magnesium; Magnesium alloys; Motor fuels; Motor reactions; Nickel; Nickel alloys
- Old TRIS Terms: Aluminum containing alloys; Crystal growth; Magnesium hydrides; Nickel inorganic compounds; Phase studies; Reaction kinetics
- Subject Areas: Energy; Geotechnology; Highways; Materials; Safety and Human Factors;
- 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