The rate-controlling mechanisms for {101̄0}〈112̄0〉 prismatic slip in Zr-O alloy crystals, in the range 77–473°K, have been determined by means of differential strain-rate and differential temperature techniques. Two separate rate-controlling processes occur; below 300°K the rate of deformation is regulated by dislocation-interstitial oxygen atom interactions and at elevated temperatures by the non-conservative motion of vacancy jogs in screw dislocations. These two mechanisms have been found to apply for alloys containing between 135–2000 ppm of oxygen.
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