INFLUENCE OF ANNEALING ON THE MECHANICAL-PROPERTIES OF OXYGEN-DOPED ZIRCONIUM AND ITS ELECTRICAL-RESISTIVITY AT 4.2 K

The variation of mechanical properties and of electrical resistivity during 4. 2 K deformation and during isochronal anneals in the range 4. 2-45 K have been determined in a series of dilute Zr-O alloys, with oxygen atomic concentrations from 30 multiplied by 10** minus **6 to 2700 multiplied by 10** minus **6. The results confirm the important influence of oxygen during deformation even at low concentrations. During recovery, oxygen promotes a strong resistivity variation at 35 K without any modification of the flow stress. This shows that the specific defects created at 4. 2 K by deformation in the presence of oxygen do not contribute to the strengthening mechanisms. The experimental data suggest rather an interpretation in terms of point defects creation and recovery.