Effect of element yttrium on β-relaxation of Cu-based metallic glasses

•The β-relaxation in Cu-Zr-Al-Y metallic glasses was investigated by DMA.•Addition of yttrium enhances the β-relaxation intensity in Cu-Zr-Al metallic glass.•The Cu46Zr42Al7Y5 metallic glass shows the most pronounced β-relaxation.•The ΔHABmix and ΔHchem affect the β-relaxation intensity of Cu-Zr-Al-Y metallic glasses. The β-relaxation behaviors of Cu46Zr47-xAl7Yx (x = 1, 3 and 5, in at.%) metallic glasses were characterized by dynamic mechanical analyzer (DMA). It is found that the Cu-Zr-Al-Y metallic glasses exhibit an observable β-relaxation behavior, and the intensity of β-relaxation will be pronounced with the increase of yttrium. The enthalpy of mixing and the mean chemical affinity of constituent elements are employed to explain the experiment results. The Cu46Zr42Al7Y5 metallic glass with the minimum negative value of mean chemical affinity shows the most pronounced β-relaxation.