Co-authors LEJČEK Pavel, DESRAYAUD Christopher, MONTHEILLET Frank & FRACZKIEWICZ Anna

Low density, high specific strength and good castability predetermine magnesium alloys to become promising engineering materials not only in transport industries. As both the alloying effect and the metal working operations can modify properties of magnesium, the present work compares the development of the microstructures of Mg–4Zn and Mg–4Zn–0.4Ca alloys (in wt.%) processed via two different deformation processes: the uniaxial compression (UC) and the equal channel angular pressing (ECAP). The processes were realized at the same temperature with the final Von Mises equivalent strain close to 1 and at three different strain rates in case of the UC tests. The microstructures were characterized by light and electron microscopy. The stress strain curves exhibited the classic aspect with a strain rate sensitivity slightly higher for Mg–4Zn than for Mg–4Zn–0.4Ca whereas the absolute value of the stress was higher in case of ternary alloy during the both deformation processes. Furthermore, the higher strain rate conditions, especially, resulted in formation of the bimodal structure composed of fine grains of several micrometers and coarse unrecrystallized grains. The aim of the current work is therefore to better describe the effect of the Ca addition into Mg–4Zn alloy on its deformation as well as to reveal the mechanism(s) of the recrystallization phenomenon observed in such alloys.