The composites of magnesium hydride and iron-titanium intermetallic

摘要

Hydride-intermetallic composites MgH_2 + X wt.% FeTi (X = 10, 30, 50) were synthesized by Controlled Mechanical Milling (CMM) in a magneto-mill. Their thermal behavior was investigated by Differential Scanning Calorimetry (DSC) and Temperature Programmed Desorption (TPD). It is found that the DSC hydrogen desorption peak temperature as well as the activation energy of hydrogen desorption of the MgH_2 constituent in composites decreases linearly with increasing volume fraction of FeTi with a coefficient of fit R2 = 0.98. A doping of the MgH_2 + FeTi composites with 5 wt.% of nanometric-size nickel (n-Ni) produced by Vale Inco Ltd. further reduces the DSC hydrogen desorption peak temperature of MgH_2 to the temperature range below 300 ℃ for the MgH_2 + 10 and 30 wt.% FeTi composites. The most effective reduction of the DSC hydrogen desorption peak temperature of the MgH_2 constituent by as much as 60 ℃ due to the catalytic effect of n-Ni is observed for the MgH_2 + 10 wt.% FeTi + 5 wt.% n-Ni composite. At this composition the composite also has hydrogen capacity slightly higher than 5 wt.%.