The high-temperature oxidation behavior of Co-Re-Cr-based alloys

Co-Re-Cr-based model alloys have been developed for high-temperature applications beyond 1,200°C. The purpose of the present investigation is to gain an insight into the oxidation mechanisms of the model Co-Re-Cr alloys and to find ways to improve oxidation resistance of this class of materials. The first generation of this class of alloys showed a rather poor oxidation resistance during exposure to laboratory air. As a consequence of the lack of protectiveness of the oxide layer, the vaporization of rhenium oxide takes place during oxidation. It has been found that Si stabilizes the Cr₂O₃ scale, enhancing the oxidation resistance significantly.