1999 Volume 49 Issue 5 Pages 209-213
Grain refinement of aluminum alloys can be achieved by introducing a large amount of lattice distortions during an intense plastic deformation. In order to introduce high plastic strain to 3004 and 5083 aluminum alloys and to restrain a dynamic recovery, a two-directional rolling method at cryogenic temperature was applied. Superiority of the two-directional rolling method was verified by a stored energy obtained from differential scanning calorimetry (DSC) analysis, by a microstructure and by a work hardening. The stored energy and work hardening given by the two-directional rolling at cryogenic temperature to 50% reduction of area were larger than those given by the other types of rolling with same reduction such as two-directional rolling at room temperature, one-directional rolling at cryogenic temperature and one-directional rolling at room temperature. A recrystallized grain size at peak temperature of remarkable exothermal reaction was smallest in the two-directional rolling at cryogenic temperature compared with in the other rolling conditions. The recrystallized grain size at the peak temperature of the exothermal reaction was decreased with increasing the stored energy. The work hardening on ST–LT cross-sectional plane of these alloys strained by the two-directional rolling at cryogenic temperature was distributed more uniformly compared with that of these alloys strained by the other rolling.
