Glass formation, corrosion behavior and mechanical properties of bulk glassy Cu–Hf–Ti–Nb alloys

Abstract Bulk glassy (Cu0.6Hf0.25Ti0.15)100−xNbx (x = 0–8 at.%) alloys with maximum diameters of 2.5–4 mm were produced by copper-mold casting. The corrosion rates in 1 N HCl and 3 mass% NaCl solutions significantly decrease with an increase in Nb content. The 6 at.% Nb alloy shows distinct spontaneous passive region in the HCl solution. The alloys with a larger amount of Nb are spontaneously passivated with lower passive current densities and higher pitting corrosion potentials in the NaCl solution. X-ray photoelectron spectroscopy analysis revealed that the formation of Hf-, Nb- and Ti-enriched surface film on the alloys could be responsible for the high corrosion resistance of the Cu–Hf–Ti–Nb alloys in HCl and NaCl solutions. Young’s modulus, compressive fracture strength and compressive plastic strain are 130 GPa, 2405 MPa and 2.8%, respectively, for the 4 at.% Nb alloy, 126 GPa, 2305 MPa and 2.1%, respectively, for the 8 at.% Nb alloy.