Textures, microstructures, anisotropy and formability of aluminum-manganese-magnesium and aluminum-magnesium alloys

In this dissertation work, the microstructure and texture evolution of continuous cast (CC) and direct chill (DC) cast Al-Mn-Mg (AA 3105 and AA 3015) and Al-Mg (AA 5052) alloys during cold rolling and annealing are systematically investigated. Macrotexture analyses were based on three-dimensional orientation distribution functions (ODFs) calculated from incomplete pole figures from X-ray diffraction by using arbitrarily defined cell (ADC) and series expansion methods. A new technique, electron backscatter diffraction (EBSD), was adopted for microtexture and mesotexture investigation. The anisotropy and formability of Al-Mn-Mg and Al-Mg alloys are correlated to the texture results.; For aluminum alloys studied in this work, a stronger Cube orientation is observed in DC hot band than in CC hot band after complete recrystallization. α and β fibers become well developed beyond 50% cold rolling in both CC and DC aluminum alloys. The highest intensity along the β fiber (skeleton line) is located between the Copper and the S orientations in both materials after high cold rolling reductions. In both CC and DC aluminum alloys, a cell structure develops with the indication of increasing CSL Σ1 boundaries during the early stages of cold rolling. There is no evidence of the development of twin boundaries (Σ3, Σ9, Σ27a & 27b) in either CC or DC aluminum alloys when the cold rolling reductions are less than 40%.; The R and Cube textures are dominant recrystallization texture components in CC and DC AA 5052 alloys. The volume fraction of the Cube component is increased by increasing cold rolling reduction and annealing temperature but not by increasing annealing time while the volume fraction of the R component is only increased by increasing cold rolling reduction. Stronger Cube and R orientations are found at the surface layer than at half-thickness layer of cold rolled hot bands after annealing.; The Cube and P textures are dominant recrystallization texture components in DC AA 3105 and CC AA 3015 alloys, respectively. When the hot bands of CC AA 3015 alloy were directly cold rolled followed by annealing the P orientation {lcub}011{rcub}<566>, accompanied by the R-Cube_ND orientation {lcub}001{rcub}<130>, was found to be the major recrystallization texture component for CC AA 3015 alloy. The Brass orientation {lcub}011{rcub}<112> transforms to the P orientation along the α fiber during annealing. The intensity of the P orientation increases with increasing cold rolling reduction and the highest intensity is obtained utilizing a 450°C anneal. The Zener drag mechanism appears to be responsible for the formation of the highly RD-elongated recrystallized grain structure.; For CC AA3015 alloy, the yield strength and ultimate strength of cold rolled hot bands at O-temper condition can be significantly increased by solid solution annealing of hot bands before cold rolling.