Mechanochemical synthesis of AlCoCrFeNi powders via high-energy ball milling

Abstract

AlCoCrFeNi powders in equimolar ratios were synthesized by mechanochemical synthesis on a high-energy ball milling machine (HEBM). The elemental and phase composition of AlCoCrFeNi powders before and after mechanochemical synthesis were investigated by X-ray phase analysis and scanning electron microscopy with EDS analysis. A preliminary mathematical calculation of the physical parameter responsible for the phase stability of the solid solution valence electron concentration (VEC) showed that the fusion of this system should form the FCC phase. However, the result of XRD analysis showed that during the synthesis a solid solution with FCC and BCC phases was formed. The EDS mapping results of AlCoCrFeNi powders after HEBM showed a homogeneous distribution of elements without macro-segregation. The results presented in this work indicate the formation of a high-entropy alloy of AlCoCrFeNi system in a short time of mechanochemical synthesis. Continuous deformation, fracture and cold welding during mechanochemical synthesis leads to increased diffusion of elements and accounts for the formation of the HEA alloy.