Masa-aki Yamada1, Toshio Shimizu2 and Kazuhide Tanaka3
1Graduate School, Nagoya Institute of Technology, Nagoya
Recovery of dislocations introduced by room temperature deformation in 99.99% pure Al and Al-(0.1∼3 wt%)Cu alloys has been investigated by means of resistivity measurement and X-ray diffraction technique. Isochronal annealing curves of resistivity of Al-Cu alloys of low Cu concentration (∼<0.3%Cu) appear to consist of, roughly, three stages, i.e., 1 (room temperature∼140°C), 2 (140°∼280°C) and 3 (280°∼340°C), respectively. In pure Al, the separation of stages 2 and 3 is not very clear. At a higher Cu concentration, these stages are almost masked by a remarkable contribution of the precipitation of Cu to the resistivity. Annealing of the half-breadth of the (220) diffraction line shows the recovery stages quite similar to those of resistivity stated above irrespective of the Cu concentration, though the amount of the overall recovery depends greatly on the concentration. The dislocation density estimated from the resistivity and the half-breadth independently increases with the Cu concentration from ∼ 1010/cm2 for pure Al to ∼ 1011/cm2 for 3%Cu after 80∼85% deformation. Stages 1, 2 and 3 may be attributed to dislocation rearrangement, subgrain-coalescence (or subgrain-grouping) and recrystallization, respectively.
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