Nucleation of paired twins at grain boundaries in titanium

An experimental study of deformation twins in a polycrystalline alpha-Ti bend specimen was performed. In some grain pairs, mechanical twins in adjacent grains were coincident at a grain boundary (T + T). Based on the identified T + T pairs, factors including twin system alignment, twinning Schmid factor, misorientation of the parent grains and parent grain size were assessed. An combination of geometric conditions was identified that can account for the formation of most of the observed T + T pairs. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.