Zener Relaxation Peak in an Fe-Cr-Al Alloy

We have studied the temperature spectra of internal friction and relative dynamic modulus of the Fe-(25 wt.%)Cr-(5 wt.%)Al alloy with different grain sizes. It is found that a peak appears in the internal friction-temperature plot at about 550 °C. The peak is of a stable relaxation and is reversible, which occurs not only during heating, but also during cooling. Its activation energy is 2.5 (± 0.15) eV in terms of Arrhenius relation. In addition, the peak is not obvious in the specimens with smaller grain size. It is suggested that the peak originates from Zener relaxation.