Cyclic twins in high-purity titanium single crystals

The titanium single crystal with special orientation was prepared and the microstructures formed during the cyclic deformation were examined by transmission electron microscope (TEM). Four important twinning systems, {1011} <1012> and {1121}<1126> (both with parallel-sides shape), {1012} <1011>(with lens-shape), {1122}<1123> (with short and narrow shape), were observed in the microstructure of titanium single crystals after cyclic loading. It is found that the deformation mechanisms of titanium single crystals vary with their orientations. With the orientation of the titanium single crystals changing from the center ([0001] direction) to the [1010]-[1120] border of the stereographic projection unit triangle, the deformation mode varies from twinning predominant to slipping predominant.