Distribution Characteristics of In-Grain Misorientation Axes in Cold-Rolled Commercially Pure Titanium and Their Correlation with Active Slip Modes

The distribution characteristics of in-grain misorientation axes (IGMA) in cold-rolled pure titanium were investigated using electron backscatter diffraction (EBSD). Depending on the orientation of individual grains, two distinct IGMA distribution patterns were observed: one with strong intensities of IGMA around ⟨0001⟩ and the other with those around ⟨ uvt 0⟩. Analyses based on the Taylor axes and Schmid factors of possible slip modes suggested that the former pattern arises from predominant activation of prism ⟨ a ⟩ slip, while activation of slip under the suppression of prism ⟨ a ⟩ slip results in the latter pattern. It was also found that prism ⟨ a ⟩ slip becomes more active with increasing strain, playing a critical role in the plasticity of pure titanium. The present work demonstrates that IGMA analysis of EBSD data may be used to explore the active slip mode in polycrystalline hexagonal-close-packed (hcp) metals deformed to moderate to large strains.