Effect of extension 101-2 twins on texture evolution at elevated temperature deformation accompanied by dynamic recrystallization. (15th April 2016) - Popova, E.
Abstract: High temperature deformation processing of magnesium and its alloys is often accompanied by dynamic recrystallization (DRX). Deformation twinning is one of the main deformation mechanisms in HCP metals, but very few works are available in literature (experimental or modelling) which investigate the effect of the deformation twinning on dynamic recrystallization. The current study provides insights regarding the deformation mechanisms of magnesium alloy during compression test at elevated temperatures. The role of the extension twins in DRX is examined using a previously developed dynamic recrystallization model based on the crystal plasticity finite element approach. In order to consider extension twins, an EBSD IPF map with reoriented twinning elements is used as input. An entire element is reoriented into twin orientation and DRX proceeds within the new microstructure. This way, twins can serve as a nucleation site because they provide high angle grain boundaries. The results of compression simulations for extruded AZ31 Mg alloy are presented and validated with the experimental data available in the literature. The results show twinning when present affects the resultant texture as most of the new nucleating grains are clos eto the twin matrix interface and have twin orientation. Graphical abstract: Highlights: A DRX model that includes the effect of extension twins is proposed. When present, twinning has a huge impact on the final texture after DRX. The model predicts that Matrix-Twin interfaces are dominant nucleation sites. Nuclei formed at twin interfaces predominantly adopt twin orientations.