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

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 ZrxTiNi-CuBe (x = 1.5, 2, 2.5, 3, and 3.5 at. %) HE-BMGs were designed according to the atomic size difference (delta), mixing enthalpy (Delta Hmix), mixing entropy (Delta Smix), valence electron concentration (VEC) and electronegativity difference (Delta chi) parameters. The electrochemical corrosion behaviors in 1 mol/L H2SO4 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 crys-tallization region compare with the traditional BMGs. In 1 mol/L H2SO4, 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.