First hydrogenation of mechanically processed TiFe-based alloy synthesized by gas atomization. (8th February 2021) - Ulate-Kolitsky, E.
Abstract: The study shows the first hydrogenation (activation) of both a cold-rolled and a ball milled TiFe-based alloy synthesized by gas-atomization. Gas atomization's primary effect was on the microstructure: a TiFe-matrix surrounded by finely distributed secondary phases. The as-received sample did not activate, probably due to the long air exposure before hydrogenation tests. Cold rolling for one and five passes (CR1-CR5) was tested as a way to reactivate the alloy. After CR1 and CR5 activation occurs with fast kinetics, reaching a capacity of 2.1-%wt. Ball milling also resulted in activation but the kinetics were sluggish, requiring more than 60 h to reach full capacity. Based on the results shown and on the comparison between the work done on the same composition synthesized by induction casting it can be concluded that gas-atomization is a good candidate for the production of TiFe-based alloys that present good kinetics and capacity after air exposure. Graphical abstract: Image 1 Highlights: TiFe-based alloy was synthesized by gas-atomization. The sample was air-exposed for 2 months before testing began. The alloy presented fast kinetics after cold rolling under air.