Exploring the microstructure,mechanical and surface properties of Ti 20 Zr 20 Fe 20 Co 20 Ni 20 high entropy bulk metallic glass (HE-BMG)

Abstract

High-entropy bulk metallic glass (HE-BMG) alloys have recently gained significant attention owing to their unique structural characteristics, outstanding mechanical performance, and potential for advanced engineering applications. In this work, we report the design and development of a Ti₂₀Zr₂₀Fe₂₀Co₂₀Ni₂₀ HE-BMG alloy synthesized via vacuum arc melting. The alloy was systematically characterized to evaluate its phase evolution, microstructure, thermal stability, and mechanical properties. Thermophysical parameters, including ΔH_mix (mixing enthalpy), δ (atomic size difference) and ΔS_mix (mixing entropy), were employed to predict the formation of a glassy phase. X-ray diffraction confirmed an amorphous structure in the as-cast state, while annealed samples revealed intermetallic phase formation. Differential scanning calorimetry measurements indicated a distinct glass transition temperature (T_g), onset crystallization temperature (T_x), and a wide supercooled liquid region (ΔT), signifying excellent thermal stability and high glass-forming ability. Scanning electron microscopy revealed a dual-phase microstructure consisting of dendritic and interdendritic regions, with energy-dispersive spectroscopy confirming elemental segregation. The potentiodynamic polarization results confirm that the HE-BMG combines excellent corrosion resistance, favorable surface wettability, and structural stability. The Ti₂₀Zr₂₀Fe₂₀Co₂₀Ni₂₀ HE-BMG demonstrates a unique balance of hardness, wear resistance, and tribological stability, surpassing many traditional alloys.