Corrosion behavior of amorphous Zr59Nb3Al10Ni8Cu20 alloy in aqueous HNO3 media

Abstract

Purpose – The purpose of this paper was to investigate the corrosion behavior of the Zr59Nb3Al10Ni8Cu20 amorphous alloy in aqueous 1M, 6M and 11.5M HNO3 media using potentiodynamic polarization and weight loss determinations. Design/methodology/approach – The electrochemical study, weight loss analysis and surface investigation were carried out on amorphous Zr59Nb3Al10Ni8Cu20 alloy that had been immersed in aqueous HNO3 medium at room temperature to understand the corrosion behavior of Zr-based amorphous Zr59Nb3Al10Ni8Cu20 alloy. The amorphous state of the alloy was investigated using X-ray diffraction. Electrochemical studies were carried out in aqueous 1M, 6M and 11.5M HNO3 media by recording open circuit potential/time and potentiodynamic polarization characteristics. Optical microscopy and scanning electron microscopy were used to examine the surface morphology of the alloy after the electrochemical tests and weight loss determinations. Findings – The electrochemical results revealed that Ecorr values shifted toward more noble values, as the concentration of the nitric acid was increased, and this was attributed to the higher oxidizing power of the nitric acid. The higher value of corrosion current density was obtained for the Zr59Nb3Al10Ni8Cu20 amorphous alloy in aqueous 11.5M HNO3 medium at room temperature. The optical microscopy and scanning electron microscopy examinations revealed that the formation of protective oxide layer on the surface of amorphous Zr59Nb3Al10Ni8Cu20 alloy leads to the improvement in the corrosion behavior in nitric acid medium at room temperature. Originality/value – The results can be helpful in finding the suitable material for fuel reprocessing applications.