Improvement of Yield Locus Calculation From Pole Figures of Zircaloy Tubes

Abstract

Dedicated to the memory of Professor Giinter Wassermann Improvement of yield locus calculation, i.e. better fit with experimental results, was achieved for Zircaloy tubes with deformation and recrysta_llization textures in the following way: (1) Replacement of information from {1010}and (0001)-pole figures by identification of preferred orientation parallel to the tube axis in combination with the basal pole density distribution in the plane between radial and tangential direction as a function of the tilt angle Yi. (2) Calculation of those parts of the yield locus which are independent of mechanical twinning. For uniaxial tensile stress parallel to the tube axis the slope m of the yield locus line for prismatic glide is given by mi cos 2),. (3) Calculation of yield locus parts depending on mechanical twinning using experimentally well established ratios of critical resolved shear stresses for prismatic slip and several twinning systems. Mechanical twinning on {ll.2}-planes was confirmed by texture analysis of plastically deformed tubes after yield locus investigation.