Mechanical alloying of nanocrystalline intermetallic compound TiFe doped by aluminum and chromium

A series of nanostructured alloys based on TiFe intermetallic compound were synthesized from the metallic elements in a planetary ball mill by solid state mechanical alloying. Al and Cr were added as doping components to a Fe-50% (at.) Ti powder mixture. Phase and structure transformations during mechanical alloying and subsequent annealing as well as hydrogen interaction with the alloys prepared were studied. It was shown that reversible hydrogen sorption capacity of the nanostructural alloys based on the TiFe intermetallic compound was of 0.7 wt.% at room temperature. The alloys studied demonstrated a simplified activation of hydrogenation. A correlation between the alloys behavior in their reactions with hydrogen and structure parameters of the hydrogenated samples has been discussed.

► By mechanical alloying method have been produced ternary TiFe-based compounds.
► The doped TiFe + 5%Al and TiFe + 4%Cr alloys demonstrated a simplified activation.
► The doped alloys demonstrated reversible hydrogen capacity of 0.7 wt.%.
► TiFe + 5%Al possessed the highest plateau in the two-phase region of the isotherms.
► The ternary compounds had a reduced hysteresis as compared with unalloyed TiFe.