Plastic Deformation of Textured Zircaloy 2

Abstract

The present study deals with deformation behaviour of textured Zircaloy 2 with two dominant orientations: basal and non-basal. During initial stages (<10%) of deformation twinning predominates slip in Zircaloy 2 of non-basal texture. Extensive electron backscattered diffraction (EBSD) analysis showed that twinning is strongly orientation sensitive. Positron annihilation spectroscopy (PAS) analysis also offered some insight towards effect of twinning/slip on positron lifetime. At higher deformations (>20%), two distinct class of grains were observed – non-deforming/non-fragmenting grains and deforming/fragmenting grains. The so-called non- deforming/non-fragmenting grains remain equiaxed even after 50% of deformation. They also have insignificant in-grain misorientation developments and have more residual stresses. Dislocation dynamics simulation showed that the dislocation interactions/mobility is insignificant in basal orientations at room temperature deformations.