Apparent steady state creep of Zn–40 wt% Al and Zn–0.5 wt% Al alloys, is studied under different constant stresses ranging from 44.7 to 78.6 MPa near the transformation temperature. The strain rate of the steady state creep is found to be maximum at 523 K for Zn–40 wt% Al alloy at 463 and 533 K for Zn–0.5 wt% Al alloy. The strain rate sensitivity parameter m amounts to 0.5 ± 0.05 at the apparent maximum strain rate peak of Zn–40 wt% Al alloy, and it was equal to 0.3 ± 0.05 and 0.4 ± 0.05, respectively, at the two maxima of strain rate of Zn–0.5 wt% Al alloy. The activation energy of the steady state creep, determined in the vicinity of these peaks amounts to (1.2 ± 0.07) × 10−22 kJ/atom; to (1.3 ± 0.07) × 10−22 kJ/atom and (1.1 ± 0.07) × 10−22 kJ/atom, characterizing dislocation climb along grain boundaries thus causing grain boundary sliding and migration of the dissolved gains into new grains of product phases. Microstructural analysis confirms that the mechanism of grain boundary sliding takes place during apparent steady state transformation creep.

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