Effect of Sc addition on the work-hardening behavior of ZK60 magnesium alloy

The effects of Sc addition on the work-hardening behavior of ZK60 magnesium alloy were investigated by using uniaxial tensile tests at room temperature. The work-hardening rate and the hardening capacity were obtained from true stress–strain curves of the as-extruded and heat-treated samples. For the as-extruded samples, the work-hardening rate decreased due to the decrease of the grain size by Sc addition. After T6 heat-treatment, both the work-hardening rate and the hardening capacity were extremely low in the samples with Sc addition. These effects were analyzed based on the evolution of microstructure as well as dislocation activity in experimental alloys. The results might be an important reference for optimizing the mechanical properties of magnesium alloys.

► The addition of Sc decreases the work-hardening rate of as-extruded ZK60 Mg alloy.
► A steep hardening drop and a fast elastoplastic transition occurred via T6 treatment.
► The precipitates may cause the fast elastoplastic transition.