Ti-Ni合金の繰り返し形状記憶特性におよぼす微量水素の影響

抄録

The effect of hydrogen on the cyclic shape memory behavior of Ti-Ni alloy has been studied. A cyclic test machine was constructed. As the result, shape memory recovery stress and recovery % decreased with a small amout of hydrogen absorption. After degasing of the hydrogen following the cathodic charge, recovery stress and recovery % approached the level of a hydrogen-free specimen. The rate of this approaching depended on the amount of cyclic strains. During deformations at martensitic phases, no effect of hydrogen was observed on the coalescence of martensite variants. The decrease in recovery stress under mild hydrogen conditions, in which no hydride has been formed, was attributed to interactions between mobile hydrogen and dislocation introduced by the cyclic deformations.