銅板における立方体再結晶組織の形成の電子顕微鏡観察

Abstract

A process of the formation of cube recrystallization texture in a heavily cold rolled copper sheet was examined mainly by using a transmission electron microscope technique, and the following characteristic findings were observed. (1) At the early stage of annealing, small recrystallized grains of more than about 1μ in diameter, with cube orientation, suddenly appear in the deformed matrix and contain annealing twins. (2) They are arranged in straight rows parallel to R.D., at each side of which crystal orientations differ. (3) Recrystallization does not occur preferentially in the region with cube orientation which has been formed during rolling. (4) The deformed matrix is slowly recovered and polygonized. Polygons slowly grow, but rarely become larger than 3μ in diameter. Recrystallized grains with cube orientation rapidly grow at the expense of the recovering deformed matrix.From these observations, it seems reasonable to think that cube recrystallization nuclei would be formed due to inverse Rowland transformation near the boundary between {112}〈111〉 twin components and also the simultaneous recovery of defects formed at the boundary during the rolling.It was clarified in a previous paper(1) that {112}〈111〉 twin components could be obtained during rolling by slip rotations in the reverse direction, therefore, if the nuclei are assumed to be formed only when the components are just in the twin relationship, the fact that the spread of the cube texture is extremely small can be explained.Recovery in the deformed matrix takes place by the decrease in the density of dislocations due to the unification of unlike ones and annihilation, and further polygonizations due to the rearrangement. Finally, a model of formation of cube texture is given.