Synthesis and characterization of nanocrystalline AlFeTiCrZnCu high entropy solid solution by mechanical alloying

Traditional alloys are based on one or two major alloying elements. High entropy alloys are equiatomic multicomponent alloys, wherein configurational entropy is maximized to obtain single phase solid solutions. The present paper reports synthesis of nanostructured equiatomic high entropy solid solutions from binary to hexanary compositions in Al-Fe-Ti-Cr-Zn-Cu system by mechanical alloying. These alloys have BCC structure with crystallite size less than 10 nm. The high entropy solid solution in these alloys is stable even after annealing at 800 degrees C for 1 h. The hardness of AlFeTiCrZnCu solid solution is 2 GPa in the sintered condition with a density of 99%. The similar nanostructured solid solutions have also been synthesized in CuNiCoZnAlTi and NiFeCrCoMnW alloys. (C) 2007 Elsevier B.V. All rights reserved.