Twinning in pure Ti subjected to monotonic simple shear deformation

Two different textures of pure Ti were subjected to monotonic simple shear and this for three different orientations of the texture versus the shear direction. EBSD and TEM observations reveal the presence of {10-12} and {11-22} twins. A statistical relevant analysis of the morphology of these twins combined with a resolved shear stress (RSS) analysis was performed. This analysis reveals that {10-12} and {11-22} twins have a similar average thickness, but the {10-12} twins show a far larger spread on their thickness compared to {11- 22} twins and can grow to almost the size of the original parent grain. Correlation of the twin
fractions with the RSS analysis shows that this RSS technique is an acceptable method explaining the difference in twin fractions for different textures and orientations. A detailed analysis shows that {11-22} twins occur in average with a smaller volume fraction but with a higher RSS, indicating they are more difficult to nucleate or grow compared to {10-12} twinning. In general a higher RSS value on the twin plane is not connected with a higher twin thickness; only in case of {10-12} twins the highest RSS values show clearly thicker twins.