Glass-Forming Ability and Corrosion Resistance of Al88Y8-xFe4+x (x = 0, 1, 2 at.%) Alloys

The effect of iron and yttrium additions on glass forming ability and corrosion resistance of Al₈₈Y_8-xFe_4+x (x = 0, 1, 2 at.%) alloys in the form of ingots and melt-spun ribbons was investigated. The crystalline multiphase structure of ingots and amorphous-crystalline structure of ribbons were examined by a number of analytical techniques including X-ray diffraction, Mössbauer spectroscopy, and transmission electron microscopy. It was confirmed that the higher Fe additions contributed to formation of amorphous structures. The impact of chemical composition and structure of alloys on their corrosion resistance was characterized by electrochemical tests in 3.5% NaCl solution at 25 °C. The identification of the mechanism of chemical reactions taking place during polarization test along with the morphology and internal structure of the surface oxide films generated was performed. It was revealed that the best corrosion resistance was achieved for the Al₈₈Y₇Fe₅ alloy in the form of ribbon, which exhibited the lowest corrosion current density (j_corr = 0.09 μA/cm²) and the highest polarization resistance (R_p = 96.7 kΩ∙cm²).