Change in Microstructure and Texture during Annealing of Pure Copper Heavily Deformed by Accumulative Roll Bonding

Abstract

Pure copper sheets were heavily deformed up to equivalent strain of 4.8 by the accumulative roll-bonding (ARB) processed and then annealed. The ARB processed copper showed the ultra-fine grained microstructure which consisted of relatively equiaxed grains having grain thickness of about 0.2 μm. The DSC measurement of the ARB processed specimens revealed that the recrystallization temperature significantly decreased with increasing the number of the ARB cycles. The stored energy did not increase so much at later stage of ARB, which corresponded with the change in microstructure. The recystallization behavior of the ARB processed copper was governed by discontinuous recrystallization characterized by nucleation and growth process. Remarkable development of cube texture ({100}〈001〉) was found in the specimen deformed to the equivalent strain of 3.2 or larger and then annealed. The concentration of the cube recrystallization texture depended on the number of ARB cycles.