Synergistic Effects of Nb and Co on the Structural Evolution and Magnetic Hardening of a Multi-Component Al82Fe12Cu2Nb2Co2 Amorphous Alloy

This research investigates the formation of an amorphous phase in a non-equiatomic aluminum-based alloy, Al82Fe12Cu2Nb2Co2, synthesized via mechanical alloying. By utilizing minor additions of Nb, Co, and Cu, structural stability and “chemical complexity” effects are achieved in a matrix dominated by a single element (82% Al). Thermodynamic analysis reveals that a moderately negative mixing enthalpy (ΔHₘᵢₓ = −6.89 kJ/mol) and elevated configurational entropy (ΔSₘᵢₓ = 5.420 J/mol·K) are the primary thermodynamic drivers of amorphization, supplemented by a transitional-regime atomic size mismatch (δ = 4.82%). The evolution of the structure, morphology, and magnetic properties of mechanically alloyed amorphous Al82Fe12Cu2Nb2Co2 as a function of milling time was systematically investigated using X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and a vibrating sample magnetometer.