Study On Li-B Based Getter Material

In order to absorb the gases in the environment where there is high temperature and pressure, thermosynthesis was adopted to prepare Li-B based porous high temperature getter material, and the basic performance of this material was researched.To study the gas sorption and releasing characteristics of Li-B alloy, the samples of Li-B alloy were heated in different atmosphere with constant rate. The result showed that Li-B alloy released gases at250～350℃and absorbed nitrogen and hydrogen quickly after450℃. The sorption capacity in hydrogen and nitrogen of Li-B alloy is related to the solution ability of N2, H2in pure lithium.By isothermy, slowly heating,fast heating hydrogen absorption test and thermal stability experiment, basic absorption characteristics of Li-B based getter were got. The sorbed quantity of the getter was determined by the free Li content, LiBC ratio in the compouds and additive content in the getter. The porous structure of the getter disappeared during absorption which lead to the decrease of the sorbed quantity. The sorbed process was controled by diffusion in static test and alternately by chemical reation and diffusion in fast heating test.Passivation could improve the utilization ratio of free Li. Mg and Al coud effecitively stop the getter from nitriding and oxidizing, but when the Al ratio was below lwt.% or up to1.5wt.% coud lead to the decreaion of sobed quantity.The sorbed quantity of lwt.% Mg,1.5wt.% Al and0.5wt.%-0.5wt.% Mg/Al samples in controlled each experiment was a maximum,which was205ml/g,217ml/g,227ml/g (0.01-0.1Mpa)Compared with ZrFeV, Li-B based getter material had a lower activation temperature, higher sorbed quantity and more stable pumping speed when they were used in modeling thermal battery atmospheres. When Li-B based getter was used in thermal battery,the temperature of battery shell dropped to a maximam of47℃...