Twinning during recrystallization cooling in α-Zr alloy

Recently, twinning induced by intergranular thermal residual stresses (ITRSs) has been first reported in a Zr alloy after beta -> alpha furnace cooling. To further explore this kind of twinning behavior, microstructures and textures of the Zr alloy during a annealing between 650 and 750 degrees C after beta quenching were investigated in the present work, by use of X-ray diffraction, electron backscatter diffraction and electron channeling contrast imaging techniques. Results indicate that the ITRS-induced twins could also occur during cooling after alpha-recrystailization annealing in the Zr alloy, closely related to both the grain size and the texture. When the recrystallization texture is relatively random, high tensile ITRSs up to similar to 200 MPa along c-axis could be accumulated. Tensile twins can only be induced by the tensile ITRS in the nearly texture-free Zr specimen with an average grain size larger than similar to 20 mu m. (C) 2013 Elsevier B.V. All rights reserved.