The biomedical as well as the aerospace sector are in constant demand of the most advanced materials. Since the Wright brothers took off for the first time, engineers are in steady search for light materials that are strong at the high temperatures prevailing e.g. in combustion chambers of aero-engines. In the biomedical sector, on the other hand, the novel alloying strategy provides an excellent opportunity to develop a new generation of alloys with excellent biocompatibility and low elastic moduli closer to that of human bone than alloys previously applied.

Here we demonstrate the opportunities offered by refractory high entropy alloys (RHEAs) for high-temperature applications in the aerospace sector. A variety of RHEAs exhibit high mechanical strength at elevated temperatures, surpassing those of the widely used superalloys, as well as good wear and corrosion resistance. The density of some RHEAs is lower than that of many superalloys, resulting in extraordinary values of the specific strength at temperatures exceeding 1000˚C. In addition to design and development of new RHEAs, research at Cranfield comprises the investigation of high temperature fatigue, creep and corrosion behaviour. A potential increase of the operational temperature of materials in turbine engines can significantly increase their efficiency. We further report on the microstructure and properties of Ti-Zr-Nb-Ta-based HEAs with good biocompatibility and high potential for applications in the biomedical sector.