INFLUENCE OF OXYGEN ON THE PRODUCTION AND RECOVERY OF DEFECTS IN LOW-TEMPERATURE DEFORMED ZIRCONIUM

The production and elimination of defects in high-purity zirconium and in oxygen doped zirconium (750 and 1100 × 10-6 at.), deformed by torsion at 4.2 K, were investigated by using electrical resistivity measurements. In all types of samples, the resistivity produced by cold-work increases linearly with shear strain. The rate of increase in resistivity is more important in oxygen doped zirconium than in the pure metal (it is multiplied by a factor of about 2.5). This increase in resistivity increment was attributed to an effect of oxygen on the deformation mechanisms. An important fraction of the excess of resistivity produced by deformation in the Zr-O dilute alloys anneals at about 35 K. The amplitude of this recovery stage increases with oxygen content and might be due to the elimination of the supplementary defects induced by oxygen atoms. Several small recovery stages were observed up to room temperature in pure zirconium and the addition of oxygen appears to have little effect on them. © 1979.