SLIP PATTERN, MICROSTRUCTURE AND LOCAL CRYSTALLOGRAPHY IN AN ALUMINUMSINGLE-CRYSTAL OF BRASS ORIENTATION (110)[112]

The evolution of microstructure and local crystallography has been exa mined in pure Al single crystals of {110}[112] orientation (brass or B -orientation) deformed by channel die compression at room temperature to logarithmic strains of epsilon = 0.5 and epsilon = 1.5. A homogeneo us cell block deformation microstructure is seen at the low strain. At higher strain the cell blocks are less distinct and some evidence of strain localisation is observed. A shallow texture gradient is seen, c orresponding to a lattice rotation about [101] and consistent with sli p occuring on just the two most highly stressed slip systems. However an analysis using the Frank formula of the dislocation content for som e of the observed boundaries suggests that a significant amount of sli p takes place on systems not predicted by a plasticity analysis. This unpredicted slip stabilises the dislocation walls on planes other than those predicted using the Frank formula.