Twinning behavior of polycrystalline alpha-uranium under quasi static compression

Deformation twins in cast uranium strained to 4.2% and 6.2% by quasi static compression were investigated using electron backscattered diffraction and transmission electron microscopy. Twin types of {130}, '{172}',{112} and '{176}'were observed in present experiment. All the operative twin variants in each twin type have the highest Schmid factor among the equivalent variants. Some {130} twins in cast uranium were inclined to disappear during subsequent loading through the re-twinning processes with Schmid factor values greater than 0.4. The '(-176)' variant was identified by indexing the electron diffraction pattern combining with the stereographic projection analysis. Twin pairs of '(-176)' e'(-17-2)' occurred in the adjacent grains were well matched with the geometric compatibility factor value of 0.933. (C) 2016 Elsevier B.V. All rights reserved.