Intergranular stresses in Zircaloy-2 with rod texture

The intergranular strains in thermally and mechanically anisotropic Zircaloy-2 with rod texture have been measured in situ under uniaxial tension along the rod axis by neutron diffraction. An in-plane biaxial stress state was developed in the grains as deformation proceeded. The tensors describing the stress state of the grains throughout the deformation process have been determined experimentally in the natural crystallographic axes system. After 5% deformation, the stress tensor components of the grains, sigma(11) and sigma(33)-stresses acting along the [a]-axes and [c]-axes lying in the transverse plane-are 230 +/- 20 MPa and -241 +/- 21 MPa, respectively. The angular dependence of the initial thermal residual stress state and the final deformed state have also been obtained. The elasto-plastic self-consistent model has been used to simulate the experiments and exhibits agreement with experiment. It appears that the introduction of basal slip {0001}[1210] considerably improves the agreement with experiment. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.