The corrosion behavior of magnesium-aluminum (Mg-Al) alloy AM50 produced by a rheocasting (RC) technique was examined in the presence and absence of CO2 at three temperatures -4, 4 and 22 degrees C. The slurry preparation in the RC material was performed with the newly developed RheoMetal process. For reference, 99.97% Mg was included in the corrosion exposures. The influence of the microstructure on the atmospheric corrosion of alloy AM50 produced by RC and high pressure die casting (HPDC) was investigated. The RC AM50 alloy showed better corrosion resistance than HPDC AM50 in all the exposure environments studied. For both materials, there was a strong positive correlation between temperature and the atmospheric corrosion rate. The superior atmospheric corrosion behavior of RC AM50 compared to HPDC AM50 is carefully discussed in relation to differences in the as-cast microstructure. This study demonstrates that producing the alloy AM50 by this type of RC technique opens the door to Mg-Al alloys as a promising candidate for various applications where corrosion resistance is of importance. (C) The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: [email protected]. All rights reserved.