Electrochemical characterization of rapidly solidified Al-(Cr,Cu,Ni,Y,Zr)-Fe alloys

• Published in: Electrochimica acta 2022-03, Vol.409, p.139836, Article 139836
• Main Authors: Młynarek-Żak, Katarzyna, Wierzbicka-Miernik, Anna, Kądziołka-Gaweł, Mariola, Czeppe, Tomasz, Radoń, Adrian, Babilas, Rafał
• Format: Article
• Language: English
• Subjects: Alloying additive; Alloys; Aluminum alloys; Aluminum base alloys; Chemical composition; Chromium; Cooling curves; Cooling rate; Copper; Corrosion; Corrosion resistance; Crystallization; Die casting; Differential scanning calorimetry; Electrochemical analysis; Electrochemical impedance spectroscopy; Electrode polarization; Foundry practice; Iron; Light diffraction; Master alloys; Mossbauer spectroscopy; Multiphase; Nickel; Optical microscopy; Plates; Quasicrystalline phases; Rapid solidification; Spectrum analysis; X-ray diffraction; Yttrium
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2022.139836

•New compositions of Al-based alloys were obtained by the high-pressure die casting method.•Yttrium alloys showed the worst corrosion resistance, for the two different cooling rates.•The best corrosion resistance was found for alloys with added zirconium.•Quasicrystalline phases were identified in Al71Ni24Fe5, Al71Cu24Fe5, Al71Cr24Fe5, and Al65Cr20Fe15 alloys.•Al65Cr27Fe8 - complex metallic alloy (CMA) phase was found for all chemical compositions of Al-Cr-Fe. The aim of this work was to investigate the multiphase structure of new Al71(Cr, Cu, Ni, Y, Zr)24Fe5 and Al65(Cr, Cu, Ni, Y, Zr)20Fe15 alloys, and the influence of chemical composition on their corrosion behavior. Samples were prepared using two different cooling rates: slowly cooled (master alloys), and rapidly solidified by high-pressure die casting into a water-cooled copper mold (plates). The structure of the studied alloys were investigated by X-ray diffraction (XRD), light microscopy, and Mössbauer spectroscopy. The crystallization mechanisms are described based on differential scanning calorimetry (DSC) heating and cooling curves. Electrochemical potentiodynamic measurements were conducted in 3.5% NaCl solution at 25 °C, and electrochemical impedance spectroscopy (EIS) tests were also carried out. The alloys were characterized by a multiphase crystalline structure, except Al65Cu20Fe15 and the plate form of Al71Ni24Fe5 alloy, for which a quasicrystalline phases were identified. Moreover, the complex metallic alloy (CMA) phase was detected for Al-Cr-Fe alloys. For samples in the form of plates, structure fragmentation was found. On the basis of the experimental polarization curves, extrapolation of Tafel curves and EIS results, the best corrosion properties were found for alloys with zirconium additions, while the alloys with addition of yttrium showed the least resistance.