A systematic study of the kinetics of the recording process, followed by X-ray diffraction and differential scanning calorimetry, of a Ni3Al based alloy, previously disordered by high energy ball-milling, is reported. X-ray diffraction analysis of isothermally annealed samples gives apparent activation energies of 1.57 ± 0.20 eV for reordering and 1.61 ± 0.07 eV for ordered domain growth. Good agreement is found between these values and that obtained from the calorimetric analysis of the continuous heating transformation, which gives a value for the apparent activation energy of 1.64 ± 0.21 eV. However, in order to correctly reproduce the calorimetric results upon isothermal annealing, an increasing value for the activation energy of the process is needed. As the experimental results suggest that point defect diffusion has an active role in the reordering process, a vacancy trapping mechanism via impurity is put forward to account for the slowing down of the kinetics of reordering. © 1993.
|Journal||Acta Metallurgica et Materialia|
|Publication status||Published - 1 Jan 1993|