Enhanced twinning-induced plasticity effect by novel {315}α/{332}β correlated deformation twins in a Ti-Nb alloy

This paper reports a new {315}(alpha '') type deformation twinning system, in adition to {130}< 310 >(alpha '') in a full alpha '' Ti-23Nb (at.%) alloy. The {315}(alpha '') twins were identified by trace analyzes based on electron backscatter diffraction (EBSD) results, meanwhile ex-situ EBSD measurements showed that both {315}(alpha '') and {130}(alpha '') deformation twins transform into {332}(beta) twins of the beta parent phase after annealing at 573 K. The crystallographic correspondences between the alpha '' twinning systems and the {332}(beta) twins have been analyzed theorectically, of which {315}(alpha '')/{332}(beta) and {130}(alpha '')/{332}(beta) correlated deformation twins were confirmed experimentally. The calculations of twinning shear, shuffle and Schmid factor were carried out to survey the priority of occurrence of these alpha '' twins. It is concluded that the remarkable work-hardening and enhanced plasticity arise from both {315}(alpha '') and {130}(alpha '') deformation twins in the present full alpha '' Ti-23Nb alloy.

Automated summary

A new {315}(alpha '') type deformation twinning system was discovered in a full alpha '' Ti-23Nb alloy, in addition to the {130}< 310 >(alpha '') system. After annealing, it was found that the {315}(alpha '') and {130}(alpha '') deformation twins transform into {332}(beta) twins of the beta parent phase. The study concluded that the presence of these deformation twins enhances work-hardening and plasticity in the alloy.