The effect of stacking-fault energy upon the evolution of microstructures during wire drawing at room temperature was studied in pure aluminium, pure copper and Cu-2.2%Al and Cu-4.5%Al alloys, which covered a range of stacking-fault energy values from 4 to 166mJ/m2. The microstructures were characterized using samples which were obtained by deforming rods of the materials to true wire drawing strain values of up to 1.47. A decrease in the stacking-fault energy changed the deformation mechanism from the formation of cell structures, and their size-refinement, in a high stacking-fault energy material to the formation of deformation bands and deformation twins in a low stacking-fault energy material. The Cu-2.2%Al alloy deformed via deformation banding at low true strain values, while deformation twins within the bands controlled the deformation mechanism at higher true-strain values. The Cu-4.5%Al, having the lowest stacking-fault energy, deformed only via deformation twins even at low true-strain values. Overlapping and intersecting deformation twins were the dominant features as the rods were drawn to higher true wire drawing strains.

The Effect of Stacking Fault Energy on the Microstructural Development during Room Temperature Wire Drawing in Cu, Al and their Dilute Alloys. S.K.Varma, V.Caballero, J.Ponce, A.De La Cruz, D.Salas: Journal of Materials Science, 1966, 31[21], 5623-30