Corrosion behavior of Zr55Cu30Al10Ni5 amorphous alloy produced by two-roll strip casting in aqueous environments

Abstract

The corrosion resistance of Zr₅₅Cu₃₀Al₁₀Ni₅ amorphous alloys fabricated by twin-roll strip casting using various process parameters was systematically investigated compared with 316 stainless steel. Potentiodynamic polarization tests indicated that pure amorphous alloy sheets possessed the best passivation in NaOH and H₂SO₄ solutions, but pitting corrosion was observed in NaCl solution. In NaOH and H₂SO₄ solution, the corrosion current density of amorphous matrix is increased by nearly two times, and the corrosion rate increases accordingly. The presence of Al-rich microcrystallites retained from the melt in the amorphous matrix reduces the corrosion resistance of the sheets. The preferential attack occurs on the microcrystallites due to the formation of a passivation film of composition and structure different from that of the substrate. The study on the corrosion properties of twin-roll cast-rolling amorphous provides theoretical guidance for expanding its practical application. It provides new ideas to extend the application of amorphous alloys in practical environments.