Open AccessDevelopment of metal hydride composites
Author(s) -
J.W. Congdon
Publication year - 1992
Language(s) - English
Resource type - Reports
DOI - 10.2172/144787
Subject(s) - hydride , materials science , hydrogen , temperature cycling , composite material , metal , sintering , hydrogen storage , pellets , metallurgy , alloy , chemical engineering , chemistry , thermal , physics , organic chemistry , meteorology , engineering
Most of current hydride technology at Savannah River Site is based on beds of metal hydride powders; the expansion upon hydridation and the cycling results in continued breakdown into finer particles. Goal is to develop a composite which will contain the fines in a dimensionally stable matrix, for use in processes which require a stable gas flow through a hydride bed. Metal hydride composites would benefit the advanced Thermal Cycling Absorption process (hydrogen isotope separation), and the Replacement Tritium Facility (storage, pumping, compression, purification of hydrogen isotopes). These composites were fabricated by cold compaction of a mixture of metal hydride granules and coarse copper powder; the porosity in the granules was introduced by means of ammonium carbonate. The composite pellets were cycled 138 times in hydrogen with the loss of LANA0.75 (LaNi{sub 4.25}Al{sub 0.75}) limited to the surface. Vacuum sintering can provide additional strength at the edges. Without a coating, the metal hydride particles exposed at the pellet surface can be removed by cycling several times in hydrogen