Microstructures and properties of ZrCu-based high-entropy amorphous alloys

Abstract

Based on the conventional metallic glass Cu₄₆Zr₄₆Al₈, the ZrCu-based high-entropy alloys were fabricated via similar-element substitution, resulting in the preparation of φ2 mm Zr₃₅Hf₁₅Ti₅Cu_17.5Ni₁₀Co_7.5Al₁₀ (denoted as Hf15) high-entropy metallic glass. The alloy's microstructures, thermal behavior, compressive properties, and corrosion resistance were systematically characterized. Its non-isothermal crystallization kinetics was also investigated. Results indicate that partially substituting Cu with Ni/Co and Zr with Ti significantly reduces the glass-forming ability (GFA) compared to the Cu₄₆Zr₄₆Al₈ alloy, whereas the introduction of Hf enhances the GFA of the ZrCuTiNiCoAl high-entropy alloys. The average compressive fracture strength and plastic strain of the Hf15 high-entropy metallic glass reach 2384 ± 192 MPa and 24.7 ± 0.6%, respectively, markedly exceeding those of the Cu₄₆Zr₄₆Al₈ metallic glass. However, the compressive fracture mechanism and fracture morphology for Hf15 remain essentially consistent with those of the conventional metallic glass. Furthermore, the Hf15 alloy exhibits considerably higher corrosion potential, supercooled liquid region ΔT_x, and apparent activation energies (E_g, E_x, E_p) for various crystallization stages compared to Cu₄₆Zr₄₆Al₈. These findings demonstrate that the high-entropy metallic glass possesses superior corrosion resistance and thermal stability relative to the conventional metallic glass for the same alloy system.