Substructures and recrystallization of deformed (100)[001]-oriented crystals of high-purity silicon-iron

Abstract

(100)[001]-oriented crystals of high-purity 3% silicon-iron were rolled to reductions of 10–90 per cent of thickness and annealed. The substructures of the deformed crystals, before and after annealing, were observed by transmission electron microscopy. At low reductions (10–20 per cent), the substructure consists of cells, 0.2–0.3 μ in diameter. With further reduction to 50 per cent, the cells elongate in the rolling direction and the crystal reorients to form two major texture components contained within deformation bands. The major components are related to the initial orientation of the single crystal by rotations about an axis normal to the (100) or rolling plane. With heavier reductions, the elongated cells evolve into sub-bands, 0.2–0.3 μ wide, separated by low-angle tilt boundaries. Groups of sub-bands form “transition bands” which separate the deformation bands and across which the change in orientation from one deformation band to the next is accomplished. When annealed, the low-angle boundaries become more perfect tilt boundaries. Migration of portions of the tilt boundaries across successive adjacent sub-bands leads to formation of recrystallization nuclei. The nuclei have the same orientation as the orientation of the sub-band from which they originate.