Effect of cold rolling and ball milling on first hydrogenation of Ti0.5Zr0.5(Mn0-xFex) Cr1, x=0, 0.2, 0.4

The first hydrogenation of Ti0.5Zr0.5(Mn1-xFex) Cr1, x= 0, 0.2, 0.4 alloys in their as-cast and heat-treated states at room temperature are reported. For alloys with x = 0.2 and x = 0.4, heat treatment had for effect of changing the rate-limiting steps of the first hydrogenation in comparison with the as-cast alloys. Effect of air exposition was investigated. We found that, after a 10 days exposure to the air, the alloys could not absorb hydrogen. However, they quickly absorb hydrogen after mechanical deformation such as ball milling for a short time or one passes of cold rolling. Ball milling produced fast kinetics but with a loss of capacity while cold rolling gave faster kinetics than the as-cast state and with minimal loss of capacity. Therefore, cold rolling is considered to be the best way to regenerate the air exposed alloys. (C) 2018 Elsevier B.V. All rights reserved.