DIRECT OBSERVATION OF THE DEVELOPMENT OF RECRYSTALLIZATION TEXTURE IN COMMERCIAL PURITY ALUMINUM

To test if oriented nucleation or oriented growth causes recrystallization texture, orientations of new grains were measured in a study of cube texture in commercial-purity aluminum after warm, near plane-strain, extrusion. After full and partial recrystallization the frequency of near-cube grains (within 20-degrees of cube) was very high, 40-75%, compared to the 4% frequency expected for random nucleation. The mean sizes of near and non-cube grains were however indistinguishable at all stages of recrystallization. Quantitative (ODF) studies of the textures of just new grains after partial recrystallization showed cube intensities of 48, 30 and 24 (times random) and values of 16 and 24 after 100% recrystallization. Brief studies of cold-rolled A 1, which gave negligible cube texture showed near random frequency of cube nuclei on partial recrystallization. The present study, with that of Hjelen et al. [Acta metall. mater. 39, 137 (1991)], shows that strong cube textures in polycrystalline aluminum come from oriented nucleation.