Effect of accumulative roll-bonding process on phase transformation and magnetic properties of polycrystalline cobalt

Abstract

In this paper, the cobalt was deformed by accumulative roll-bonding (ARB) process. The phase transformation behavior of cobalt during accumulative rolling and its effect on the magnetic properties of polycrystalline cobalt were investigated. Twinning occurs in α-Co phase with hexagonal closepacked (HCP) structure during the ARB process, and a large number of twin boundaries hinder the phase transformation from β-Co phase to α-Co phase. {0001} texture forms in α-Co phase during rolling deformation, however, the intensity of {0001} texture decreases with the growth of twins. The coercivity of polycrystalline cobalt gradually decreases with the increasing rolling deformation, which can be attributed to the evolutions of phase and texture.