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Title: Kinetics of reordering of Ni[sub 3]Al disordered by ball-milling

Journal Article · · Acta Metallurgica et Materialia; (United States)
; ; ;  [1];  [2];  [3]
  1. Univ. Autonoma de Barcelona (Spain). Dept. de Fisica
  2. Univ. degli Studi di Trento (Italy). Dipt. di Ingegneria dei Materiali
  3. Univ. of Cambridge (United Kingdom). Dept. of Materials Science and Metallurgy

A systematic study of the kinetics of the reordering process, followed by X-ray diffraction and differential scanning calorimetry, of a Ni[sub 3]Al 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 [plus minus] 0.20 eV for reordering and 1.61 [plus minus] 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 [plus minus] 0.21 eV. However, in order to correctly reproduce the calorimetric results obtained upon isothermal annealing, an increasing value for the apparent 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.

OSTI ID:
6303384
Journal Information:
Acta Metallurgica et Materialia; (United States), Vol. 41:4; ISSN 0956-7151
Country of Publication:
United States
Language:
English