ECO-Al alloys are introduced as a game-changer for the aluminum industry and it is of utmost importance to determine the role of alloying elements on their processing characteristics. This study investigates the effects of Cr on the hot deformation behavior of newly-developed ECO-7175 alloy. ECO-7175 samples with and without Cr were hot-compressed using a Gleeble simulator (temperature range of 350-500˚C and strain rates of 0.001-1s-1). The results were used to study the constitutive equations, the processing maps, and the microstructural evolution of the alloys. In Cr-containing alloy, the analysis of the deformation activation energy revealed that the rate-controlling mechanisms of the deformation change gradually from self-diffusion of Al (or diffusion of Mg in Al) to diffusion of Cr in Al by decreasing the Zener-Hollomon parameter. The analysis of the processing maps of Cr-containing alloy showed that the dynamic recrystallization (DRX) zone is limited to the deformation at high temperatures and low strain rates and expands with increasing applied strain. On the other hand, it was found that the self-diffusion of Al (or Mg in Al) is the only rate-controlling mechanism during hot deformation of Cr-free alloy in all processing conditions and its DRX zone is independent of the plastic strain.
