Three dimensional crystallographic orientation relationships for hexagonal close packed structure to face centered cubic structure transformation in pure titanium

In this work, two types of stress induced hexagonal close packed structure to face centered cubic structure transformation were observed in cold-rolled pure titanium. The corresponding transformation mechanisms were revealed by high resolution transmission electron microscopy. By using stereographic projections and selected area electron diffraction simulations, the three dimensional orientation relationships for the two types of phase transformation were deduced for the first time. The deduced orientation relationships were also verified by high resolution transmission electron microscopy observations, and the dark side of the basal-type face centered cubic phase was revealed at the atomic scale. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.