Corrosion behaviour of Zr-based bulk glass-forming alloys containing Nb or Ti

• Published in: Materials letters Vol. 57; no. 1; pp. 173 - 177
• Main Authors: Raju, V.R, Kühn, U, Wolff, U, Schneider, F, Eckert, J, Reiche, R, Gebert, A
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2002; Elsevier
• Subjects: Applied sciences; Bulk metallic glass; Corrosion; Corrosion mechanisms; Exact sciences and technology; Metals. Metallurgy; Passivity; Pitting; Zirconium-based alloys; Pitting; Zirconium-based alloys; Corrosion; Passivity; Bulk metallic glass; Alloying element; Experimental study; Corrosion protection; Multi-element alloys; Corrosion resistance; Casting; Pitting corrosion; Anodic corrosion; Transition metal alloy; Microstructure; Auger electron spectrometry; Zirconium base alloys; Metallic glass; Passivation
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/S0167-577X(02)00725-5

Cylindrical bulk samples of Zr–Cu–Al–Ni–X (X=Nb, Ti up to 5 at.%) alloys with 3 mm diameter were prepared by copper mould casting. The microstructure of the samples was characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The corrosion properties of the Nb- and Ti-containing alloys were studied in comparison to those of the bulk glass-forming Zr 55Cu 30Al 10Ni 5 alloy in aqueous electrolytes at 298 K. It was found that in 0.1 M Na 2SO 4 electrolyte with pH=8, the corrosion resistance of these new alloys is comparable to that of the quaternary alloy. However, in 0.01 M NaCl solution, the pitting susceptibility of the Nb- or Ti-containing bulk alloys is significantly lower. Auger electron spectroscopy depth profile analysis (AES) was applied to passivated sample surfaces in order to study the role of alloying elements for corrosion protection. Nb-containing amorphous alloys with higher Zr content than that of the Zr 55Cu 30Al 10Ni 5 reference alloy form comparatively thinner passive films which are more enriched in copper and nickel species close to the interface oxide/alloy and which provide a lower protective effect.