In this paper,cyclic twins in high purity single titanium crystal and commerical purity titanium were observed with TEM and OM.It is showed that twinning was an important deformation mode.

• 采用透射电子显微镜和光学显微镜观察高纯钛单晶及工业纯钛循环变形过程中形成的孪晶，证实了孪晶是纯钛循环变形的一种重要方式几乎在所有位向的拉伸时钛单晶中都有孪生发生。