Orientation dependence of deformation twinning in Cu single crystals

摘要

Cu single crystals were subjected to dynamic compression plastic deformation to investigate orientationdependent twinning.The experimental results showed that twinning is closely related to the ratio of the maximum Schmid factor for twinning partial(m_T)to the maximum Schmid factor for perfect dislocation(m_S),i.e.,m_T/m_S,rather than m_T.The twin volume fraction V_Tincreases with the m_T/m_Svalue and the most favorable orientation for twinning has the maximum m_T/m_Svalue(1.15).The relationships of m_T/m_Swith both effective stacking fault energy γ_(eff)and threshold stress for twinning τ_Twere established for understanding orientation-dependent twinning.Further insights into the orientation-dependent twinning and guidance for developing bulk high density nanotwinned materials are provided.