Abstract
The high temperature creep data for an ODS Cu-0.01ZrO₂ alloy reported by Nagorka et al. (Metall. Mater. Trans. A, 26A, 1995, p. 873) are reinterpreted applying some microstructural data of the same authors. Two concepts of creep in this dispersion strengthened alloy are considered: (1) the true threshold stress concept and (2) the concept of thermally activated detachment of dislocations from interacting dispersed particles, specifically the model of creep presented by Rösler and Arzt - RA model (Acta Metall. Mater., 38, 1990, p. 671). The creep data analysed cover relatively narrow interval (not exceeding three orders of magnitude) of the creep strain rates measured at two temperatures only. Nevertheless, the application of the true threshold stress concept led to the conclusion that the creep in the ODS Cu alloy is lattice-diffusion-controlled and the true stress exponent of creep rate n is close to that of creep in copper. The model of creep, controlled by thermally activated detachment of dislocations from fine interacting particles, provides perhaps an alternative but certainly far from satisfactory interpretation of creep in the alloy under consideration. The model of diffusional creep inhibited by the particles located at grain boundaries developed by Arzt, Ashby and Verrall - AAV model (Acta Metall., 31, 1983, p. 1977) and accepted by Nagorka et al. was not found to be relevant to account for the creep behaviour of the alloy even at the creep strain rates below about 10^-6s^-1.

Key words
ODS Cu alloys, high temperature creep, threshold-like creep behaviour, true threshold stress, thermally activated detachment

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