Eutectic aluminum alloys, based on the Al-Ce and Al-Co binary systems, have been developed to provide alternative materials for elevated temperature applications, aiming to replace heavier steels and more expensive titanium alloys. These alloys are further strengthened with L12-ordered precipitates, containing Er, Sc, and Zr, which provide a high level of mechanical strength and microstructural stability. In this study, we aim to investigate the effects of long-term heat treatments and evaluate their resulting mechanical properties. The microstructure of the alloys was analyzed using various techniques, including electron microscopy and X-ray diffraction. The mechanical properties were evaluated using tensile and hardness tests. The results showed that these alloys provide good microstructural stability and maintained their mechanical properties after long-term heat treatments, suggesting that they have potential for use in applications at elevated temperatures, particularly in the aerospace and automotive industries.