Lt. Zhang et al., Hydrogen absorption and desorption in a B2 single-phase Ti-22Al-27Nb alloybefore and after deformation, ACT MATER, 49(5), 2001, pp. 751-758
The effects of deformation on the hydrogen absorption/desorption behavior o
f a B2 single-phase Ti-22Al-27Nb (at.%) alloy were investigated mainly by m
easuring the static pressure-composition (P-C) isotherms from room temperat
ure to 100 degreesC for specimens quenched from 1200 degreesC and deformed
to 5-similar to 90% in compression or by cold-rolling. beta hydride is form
ed at a very low hydrogen pressure similarly to bcc hydrogen absorbing allo
ys. In as-quenched specimens; further absorption to gamma hydride is sluggi
sh and there is no obviously reverse gamma --> beta hydride transformation.
Both the beta --> gamma and reverse gamma -->beta hydride transformations
are promoted by deformation. The best hydrogen absorption/desorption proper
ties are attained in specimens deformed to 5-10%, the deformation structure
of which consists of well-aligned and uniformly distributed <111> screw di
slocations. The beneficial effects of deformation on the hydrogen absorptio
n/desorption behavior of the alloy are interpreted in terms of similarities
between atomic displacements around straight screw dislocations and those
taking place during the beta-gamma hydride transformation. (C) 2001 Acta Ma
terialia Inc. Published by Elsevier Science Ltd. All rights reserved.