ナノ結晶電着ニッケル薄膜の機械的性質および疲労強度に及ぼす結晶粒径の影響

抄録

Nano-crystallization technique can improve the strength of metallic materials without reducing the toughness by refining the grain size up to nano region. In the present study, nano-crystalline nickel films with 10 μm in thickness were produced by electrodeposition which is one of the nano-crystallization techniques. Four types of electrodeposition baths with different concentration of brightener were prepared: 0.0g/L in bath A, 0.4g/L in bath B, 0.8g/L in bath C and 1.6g/L in bath D. In addition, nickel thin films with heat treatment (250°C, 1 h) were also prepared. From the results of tensile tests, the tensile strength increases with increasing the concentration of the brightener. From the results of the fatigue tests, the fatigue limit increases with increasing the concentration of the brightener. High concentration of the brightener is effective for improving the tensile strength, the 0.2 % proof strength and fatigue limit of Ni film.