Effect of strain path change on the evolution of texture and microstructure during rolling of copper and nickel

Abstract

The effect of strain path change during rolling has been investigated for copper and nickel using X-ray diffraction and electron back scatter diffraction as well as crystal plasticity simulations. Four different strain paths namely: (i) unidirectional rolling; (ii) reverse rolling; (iii) two-step cross rolling and (iv) multi-step cross rolling were employed to decipher the effect of strain path change on the evolution of deformation texture and microstructure. The cross rolled samples showed weaker texture with a prominent Bs {1 1 0}〈1 1 2〉 and P(BND) {1 1 0}〈1 1 1〉 component in contrast to the unidirectional and reverse rolled samples where strong S {1 2 3}〈6 3 4〉 and Cu {1 1 2}〈1 1 1〉 components were formed. This was more pronounced for copper samples compared to nickel. The cross rolled samples were characterized by lower anisotropy and Taylor factor as well as less variation in Lankford parameter. Viscoplastic self-consistent simulations indicated that slip activity on higher number of octahedral slip systems can explain the weaker texture as well as reduced anisotropy in the cross rolled samples.