Changes of Structures by Rolling in Pure Aluminum Bi-Crystals

Abstract

For the purpose of clarifying the influence of grain boundaries on the hardness and structure, a investigation was performed on changes in hardness as reported previously. In the present study, changes in structure were investigated.
Bi-crystals were prepared from 99.999% pure aluminum ingots by Bridgman’s method. The bi-crystals were rolled by 95% at room temperature.
Main experimental results obtained were as follows:
(1) Recrystallization occurs in a crystal grain of which both the direction normal to the rolling plane and the rolling direction lies near ⟨111⟩, but no recrystallization is observed in a crystal grain of which the both direction normal to the rolling plane and the rolling direction lies near ⟨100⟩ or ⟨110⟩. These phenomena were observed by means of micro-structure studies and Laue X-ray photography.
(2) The shape of the bi-crystal boundary was not changed after rolling of high working degree.
(3) Deformation bands were observed in a crystal of which the vertical direction of the rolling plane and the rolling direction is near ⟨111⟩.