The activation energies of antiphase-boundary tube annihilation in Fe-Al

Abstract

Abstract Analysis of the exothermic peaks obtained at different heating rates during continuous heating in a differential scanning calorimeter of a quenched B2-structured Fe-40at.% Al single crystal yielded a value for the activation energy for vacancy annihilation of 131 ± 8 kJ mol−1, which is very close to the accepted value. Having shown the utility of this method, it was used to determine the activation energies associated with the annihilation of antiphase-boundary (APB) tubes from cold-rolled Fe-40at.% Al and Fe-83 at. % Al single crystals. The activation energies obtained were 101 ± 9kJ mor−1 and 67 ± 9kJ mol−1 respectively. Magnetic measurements showed that the rolled Fe-43 at.% Al specimens need less time and a lower temperature to anneal out the APB tubes produced during rolling compared with Fe-40 at.% Al specimens, consistent with the lower activation energy in this alloy.