Reconsideration of Anelastic Relaxation Peaks in Pure Aluminium

The temperature dependence of internal friction (T-tan ψ curves) in pure aluminium (Al) is measured at sixteen different frequencies. Based on T-tan ψ curves, the frequency dependence of internal friction (f-tan ψ curves) is also obtained by the interpolation method. An internal friction peak is observed in both the T-tan ψ curves and the f-tan ψ curves. The activation energy of the peak in the f-tan ψ curves is found to be 2.08 ± 0.02eV and compared to the value of 1.60 ± 0.04eV in the T-tan ψ curves. It is suggested that the change of relaxation strength with temperature should be considered when one calculates the activation energy of the peak in T-tan ψ curves.