アルミニウム-2 wt%マグネシウム合金の恒温軟化スペクトラムに関する電子顕微鏡的研究

抄録

Changes in the microstructure during cold drawing and at various stages of the isothermal softening process of a highly cold drawn aluminium-2 wt% magnesium alloy have been studied by a transmission electron microscopy and X-ray measurements.
Nearly parallel narrow segments, began to occur with the deformation, which appear to be a basic characteristic of the microstructure during cold drawing and are named the “Narrow band”.
The structure of the narrow bands is closely related to the ⟨111⟩ preferred orientation resulting from cold drawing.
In the steps proceeding the primary recrystallization, the density of dislocations decreases slowly and gradually, and the formation of sub-grains begins, and a well-defined substructure is developed chiefly by the coalescence of sub-grains in the narrow bands during isothermal annealing.
The present experiment indicates that the coalescence of sub-grains leads to the formation of recrystallization nuclei in the early stage of primary recrystallization.