Effect of Al addition on the microstructure, mechanical and wear properties of TiZrNbHf refractory high entropy alloys

A series of AlxTiZrNbHf refractory high entropy alloys (RHEAs) were prepared to investigate the mechanical and wear properties. Despite the different crystal structures of each constituent, the RHEAs exhibited body centered cubic (BCC) phase structures as revealed by X-ray diffraction and transmission electron microscopy. Along with the primary BCC phase, another ordered BCC phase appeared in AlTiZrNbHf, being supported by a high negative mixing enthalpy (<-16.28 kJ-mol(-1)) and a low valence electron concentration (< 4.04). The improved mechanical properties and wear resistance by the Al addition are ascribed to severe lattice distortion and second phase strengthening. These findings highlight significant alterations in the microstructure, mechanical and wear properties with the Al addition, which are beneficial to the design of alloys for wear applications.

Automated summary

A series of AlxTiZrNbHf refractory high entropy alloys (RHEAs) were prepared to investigate their mechanical and wear properties. It was found that the addition of Al improved the mechanical and wear resistance properties by causing lattice distortion and second phase strengthening in the alloys. The study highlighted significant alterations in microstructure, mechanical properties, and wear resistance with the inclusion of Al, which is beneficial for designing alloys for wear applications.