EFFECT OF INITIAL TEXTURES ON DEFORMATION MECHANISMS AND TEXTURE EVOLUTIONS OF ZR-ALPHA POLYCRYSTALS DEFORMED BY CHANNEL-DIE COMPRESSION TESTS

Channel die compression tests were performed at room temperature on zi rconium polycrystalline samples (Zr 702) up to 40% plastic strain. Thr ee initial textures (T3, T4 and T5) with [c] axes concentrations along the die axes (ND, TD and LD) are considered. The macroscopic stress-s train curves, the active mechanisms (slip and twinning systems) and th e texture evolutions obtained for T3, T4 and T5 show an anisotropic be haviour of the material. Identification of the deformation modes by EB SD (Electron Back Scattering Diffraction) indicates an important contr ibution of {<10(1)over bar 0>} prismatic glide in the different sample s. Estimates of twinned volume fractions show an important activation of {<10(1)over bar 2>} twinning in the T5 samples. The correlation bet ween the active mechanisms and the texture evolutions is partly explai ned by geometrical considerations. (C) 1997 Elsevier Science S.A.