2014 Volume 55 Issue 8 Pages 1168-1174
The effect of substitution elements on hysteresis and flatness of the equilibrium pressure plateau in ZrxTi1−xMn0.8V0.2Ni1.0 was investigated and suitable hydrogen storage alloys for a metal hydride (MH) actuator in rehabilitation devices were developed. By changing the Zr/Ti ratio, the equilibrium pressure was tuned for the MH actuator. Al substitution made the hysteresis factor smaller, while Fe and Cu substitution did not. In addition, it was confirmed that ferrovanadium is available in these alloys to reduce not only the material cost but also the hysteresis factor leading to better properties for the MH actuator. The developed Zr0.5Ti0.5Mn0.8V0.2Ni0.9Al0.1 showed no significant reduction of hydrogen capacity and no significant change in the shape of the pressure-composition (P-C) isotherms even after 1000 cycles.
