The volume expansions of Ti0.95Zr0.05V0.4Mn1.45Fe0.1Cr0.05 alloy during
hydrogenation with various conditions have been investigated. The theoretical
volume expansion measured with XRD for this alloy with hydrogenation was 21%.
The apparent volume expansion of this alloy ingot with hydrogenation was composed
of two effects. One is a hydrogenation and the other is a pulverization. The
apparent volume of free alloy powder was 1.8 times greater than that of an ingot,
implying the pulverization effect on the apparent volume expansion is 80%. The
apparent volume expansion of the alloy ingot with hydrogenation under a unconstrained
condition was about 80 (±15)%, much smaller than that of free alloy
powder which expected as 118%. In addition, The apparent volume expansion of
the alloy ingot with hydrogenation under a constrained condition(Al container)
was about 50%, much smaller than that of the unconsrained. This reduced apparent
volume expansion of the alloy ingot could be attributed to an arrangement
of alloy powder keeping its original shape of the ingot even after hydrogenation.