Abstract Scope |
Refractory high-entropy alloys (RHEAs), particular type of high entropy alloys (HEAs), comprising of mainly refractory metals. RHEAs have emerged as potential structural materials for ultrahigh-temperature applications. These novel alloys require a combination of balanced oxidation resistance and mechanical properties. Previous studies lack the guidelines to develop materials which can form a protective and stable oxide layer such as alumina during high temperature exposure in combination with optimum mechanical properties. Here, we have introduced a strategy to form a stable and protective alumina layer upon high temperature exposure for ductile RHEAs. Ductility is first achieved by maintaining the number of total valence electrons low, tuned by adjusting the alloy composition. Later, oxidation protection is enhanced by two step aluminizing i.e., low activity aluminizing followed by the high activity one. Furthermore, through this approach, the ductile RHEAs resistance to oxidation improved tremendously, thus bringing in a new perspective towards their development. |