Preparation and electrochemical corrosion performances of Zr-Ti-Ni-Cu-Be high-entropy bulk metallic glasses.

• 6 mm diameters non-equiatomic Zr x TiNiCuBe (x = 1.5, 2, 2.5, 3, and 3.5 at. %) HE-BMGs were obtained by suction casting designed according to the atomic size difference (δ), mixing enthalpy (ΔH mix), mixing entropy (ΔS mix), valence electron concentration (VEC) and electronegativity difference (Δχ) parameters. • The obtained HE-BMGs have higher glass forming ability, thermal stability and a wider crystallization zone, due to the sluggish diffusion effect of high-entropy alloy. • In 1 mol/L H 2 SO 4 solution, the designed HE-BMGs exhibit obvious passivation behavior and have higher corrosion potential, lower corrosion current density and passive current density, wider passivation interval and larger polarization resistance, proving their better corrosion resistance than 304L stainless steel. • The designed HE-BMGs possess a bit lower corrosion potential but much lower i corr than 304L stainless steel in cyclic polarization. As sweeping potential increases, the HE-BMGs show lower pitting potential than 304L stainless steel, but have better re-passivation ability for pitting. The high entropy bulk metallic glasses (HE-BMGs) are the mathematical intersection of sets of bulk metallic glasses (BMGs) and high entropy alloys (HEAs). Owing to their unique structural and compositional features, HE-BMGs exhibit peculiar physical, chemical, and mechanical properties. Herein, non-equiatomic alloys Zr x TiNiCuBe (x = 1.5, 2, 2.5, 3, and 3.5 at. %) HE-BMGs were designed according to the atomic size difference (δ), mixing enthalpy (ΔH mix), mixing entropy (ΔS mix), valence electron concentration (VEC) and electronegativity difference (Δχ) parameters. The electrochemical corrosion behaviors in 1 mol/L H 2 SO 4 and 3.5% NaCl solutions were also studied in this paper. The results show that fully glassy rods with diameters of 6 mm were obtained. The designed HE-BMGs show large glass forming ability, a narrow supercooled liquid region and a wide crystallization region compare with the traditional BMGs. In 1 mol/L H 2 SO 4 , the designed HE-BMGs show very small corrosion current densities and a typical passivation behavior, and their corrosion resistance is much better than that of 304L stainless steel. In 3.5% NaCl, the prepared HE-BMGs also have much smaller corrosion current densities than 304L stainless steel. As potential increases, the pitting corrosion resistance is not as good as 304L stainless, however, the HE-BMGs all show superior pitting corrosion re-passivation abilities. [ABSTRACT FROM AUTHOR]