Local structure and properties of refractory high-entropy alloys

High-entropy alloys (HEAs) are a hot topic of research for their many interesting potential applications and ease of synthesis. In HEAs generally 4 or more different metallic elements are randomly distributed in a W or Cu type average structure. Refractory elements based HEAs can have potential use in high-temperature aerospace applications and ambient temperature use in micro-manipulators, MEMS etc. In HEAs the observed mechanical and functional properties have largely been qualitatively explained and a deeper quantitative study was much awaited. In this work 6 different refractory HEAs have been synthesized and critically analyzed for local structure, mechanical properties and atomistic modeling to explain their mechanical and structural properties. Experimental methods like powder and single-crystal XRD, neutron diffraction, HRTEM and 3d APT were utilized to investigate into the structure. Micro and bulk mechanical properties were adequately explained by different models and MD simulations. In some HEAs short-range ordering can significantly influence the mechanical and structural properties, which have been explained by MD and ab initio calculations.