A method to produce an iron-titanium alloy for H2-storage

摘要

Anew and inexpensive way to produce TiFe — an alloy with potential as a material for reversibly storing hydrogen — has been developed by the research groups of professors Zenji Horita and Etsuo Akiba at Kyushu University (Fukuoka, Japan; www.kyushu-u. ac.jp). The TiFe is made by a technique known as high-pressure torsion (HPT), whereby a precursor is both pressed and twisted between two dies under high pressure. Treating a brittle TiFe with B2 structure as a precursor, the HPT (8 MPa pressure) yields a TiFe alloy exhibiting heterogeneous microstruc-tures composed of nano-grains, coarse-grains, amorphous-like phases and disordered phases with a high, steady-state hardness of around 1,050 Hv. The TiFe made by this process adsorbs 1.7 wt.% H2, which is near the theoretical maximum of 1.9 wt.%.