Texture and microstructure evolution of commercially pure titanium during hot rolling: Role of strain-paths

Abstract

Commercially pure (CP) titanium plates were subjected to hot rolling down to 50%, 70%, 80% and 90% reduction in thickness through unidirectional rolling (UDR), multistep cross-rolling (MSCR) and reverse-rolling (RR). It was observed that the samples had dominant basal texture (basal fiber) irrespective of the reduction percentages and the modes of rolling. Two types of twins, {11̅02}<112̅0> type tensile twins and {12̅12}<11̅00> type compressive twins, were observed in the microstructures. These twins were present in more abundance in the samples processed under MSCR and RR conditions, particularly for 50% reduction in thickness. A decreasing trend of average grain size, average grain orientation spread and fractions of twin boundaries as well as low angle grain boundaries was observed as a function of deformation for the UDR and RR strain paths. The MSCR samples have shown a deviation from the trend, which has been attributed to dominance of twinning in the deformation mechanism.