Synthesis of AlFeCuCrMgx (x = 0, 0.5, 1, 1.7) alloy powders by mechanical alloying

• Novel AlFeCuCrMgx (x = 0, 0.5, 1, 1.7) HEAs were prepared by mechanical alloying.
• Phase evolution and lattice parameter were studied by X-Ray Diffraction.
• Crystallite size and lattice microstrain calculated failed to obey the Williamson–Hall method.
• Criterions for formation of simple solid solution were compared to the thermodynamic parameters of the present HEAs.
• Increase in the Mg concentration in AlMgxFeCuCr (x = 0, 0.5, 1, 1.7) HEAs supports the formation of BCC phase.

Novel AlFeCuCrMgx (x = 0, 0.5, 1, 1.7 mol) high-entropy alloys (HEAs) were synthesized by mechanical alloying. The effect of Mg content on the phase evolution of HEAs was investigated using X-Ray diffractometry (XRD), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) pattern analysis. The particle morphology and composition of HEAs were investigated by scanning electron microscopy (SEM). Thermodynamic parameters were calculated and analyzed to explain the formation of a solid solution. XRD analysis revealed BCC as major phase and FCC as a minor phase in as-milled AlFeCuCr and AlFeCuCrMg0.5 HEAs. Also, XRD analysis of as-milled AlFeCuCrMg, AlFeCuCrMg1.7 confirmed the formation of two BCC phases (BCC 1 and BCC 2). TEM–SAED analysis of AlFeCuCrMgx HEAs concurred with XRD results. Microstructural features and mechanism for solid solution formation have been conferred in detail. Phase formation of the present HEAs has been correlated with calculated thermodynamic parameters. Differential thermal analysis (TGA-DTA) of these alloys confirmed that there is no substantial phase change up to 500 °C.

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