Phase transformation of the metastable Al6Fe intermetallic phase to Al3Fe in an Al-0.58 wt Pct Fe alloy was investigated by Mössbauer spectroscopy. The kinetics of the process were estimated by the Avrami equation:A=A 0e -(kt). The concentration of Al6Fe, A, was followed in time, t, at different temperatures between 650 and 580 °C. It was found that the kinetics of the phase transformation at 650 ‡ differed from those found in the 635 to 580 °C temperature range. In the latter case the activation energy of the overall process was 3.33 ± 0.47 eV as determined from the rate constants (K). The optimal value obtained for the parameter n was 0.71. A simple model suggested for the mechanism of the transformation proved that this process was interface controlled between 635 and 580 °C.
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