Hydrogen-induced internal friction of Zr-based bulk glassy alloys in a rod shape above 90 K

Hydrogen-induced internal friction of Zr₆₅Al _7.5Ni₁₀Cu_17.5 bulk glassy alloys in a short rod shape (1.5mm in diameter, 44mm in length) have been investigated above 90K using a vibrating reed technique. A quite broad and asymmetric peak is observed around 240K (H=2.21at.%) in the temperature dependence of internal friction. Strain amplitude dependence of internal friction of Zr_63.57Al _7.32Ni_9.79Cu_17.11H_2.21 have been also measured at about the peak temperature and room temperature. It is found that the internal frictions at both temperatures are independent of the strain amplitude. Effects of hydrogen concentration (H=0.24-2.21at.%) on the temperature dependence of internal friction have been also clarified. The peak temperature decreases with increasing hydrogen concentration and the peak internal friction increases almost linearly. These results are compared with the reported results of Zr-Al-Ni-Cu-Pd bulk glassy alloys and discussed from the viewpoints of local structure of the Zr-based glassy alloys.