1 Department of Wind Energy, Technical University of Denmark2 Materials science and characterization, Department of Wind Energy, Technical University of Denmark3 Tsinghua University4 Tsinghua University
A combination of electron channeling contrast (ECC) and electron backscatter diffraction pattern (EBSP) techniques has been used to follow in situ the migration during annealing at 323 K (50 A degrees C) of a recrystallizing boundary through the deformed matrix of high-purity aluminum rolled to 86 pct reduction in thickness. The combination of ECC and EBSP techniques allows both detailed measurements of crystallographic orientations to be made, as well as tracking of the boundary migration with good temporal resolution. The measured boundary velocity and the local boundary morphology are analyzed based on calculations of local values for the stored energy of deformation. It is found that the migration of the investigated boundary is very complex with significant spatial and temporal variations in its movement, which cannot directly be explained by the variations in stored energies, but that these variations relate closely to local variations within the deformed microstructure ahead of the boundary, and are found related to the local spatial arrangements and misorientations of the dislocation boundaries. The results of the investigation suggest that local analysis, on the micrometer length scale, is necessary for the further understanding of recrystallization boundary migration mechanisms.
Metallurgical and Materials Transactions a - Physical Metallurgy and Materials Science, 2014, Vol 45A, Issue 6, p. 2899-2905
MATERIALS; METALLURGY; PLANE-STRAIN COMPRESSION; DEFORMED METALS; ORIENTATION DEPENDENCE; GRAIN-ORIENTATION; STORED ENERGY; PURE ALUMINUM; MOBILITY; GROWTH; MICROSTRUCTURE; PROTRUSIONS; Single crystals; Crystallographic orientations; Deformed microstructure; Dislocation boundaries; Electron back scatter diffraction; Electron channeling contrasts; In-situ investigations; Spatial and temporal variation; Spatial arrangements; Recrystallization (metallurgy)