Internal friction in Fe-Al-Si alloys at elevated temperatures

Anelastic effects in ternary Fe-Al-Si alloys at elevated temperatures (from 400 to ∼700 °C) have been studied by mechanical spectroscopy. The contributions of several damping mechanisms (high temperature background, Zener and grain boundary relaxations), which are sensitive to the structural state in the temperature range studied, are analysed. The structure of the alloys was examined by different methods. The results of computer analyses of the experimental data justify the superposition of several relaxation processes. Parameters of the Zener relaxation in two ternary Fe-Al-Si alloys are determined: the peak temperature is about 545 °C (f ≈ 2 Hz); the mean value of the activation energy of the Zener relaxation is about 2.54 eV.