Electrochemical hydrogenation after mechanical activated near equiatomic Ti-Ni powder

Abstract

It has been studied an effect of mechanical activation in a planetary ball milling on the electrochemical hydrogenation of Ti-Ni powder near equiatomic content. It has been shown that average particle sizes measured by scanning electron microscope decreased from 11.1 to 7.8 μm up to 30 s mechanical activation, then increased to 33.2 μm for 300 s activation. Beside, with an increase in the time of mechanical activation was formed state with small the coherently diffracting domain which correspond to quasi-amorphous state of material. It has been shown that after hydrogenation, the particle size distribution did not change. There is an incubation time hydrogenation for mechanical activation, when hydrogenation is not occurring. Mechanical activation for more than 30 s leads to the formation of the Ti2NiHx phase based on the Ti2Ni and 50 s activation is sufficient to form the Ti2NiH0.5 stoichiometry. For a longer mechanical activation a phase with the stoichiometry Ti2NiH0.85 was formed and to obtain the Ti2NiH stoichiometry it is necessary to carry out activation for 4.5 hours.