Analysis of thermodynamic parameters for designing quasicrystalline Al-Ni-Fe alloys with enhanced corrosion resistance

In this work, the compositions of Al-Ni-Fe alloys were determined based on thermodynamic parameters optimization. Decagonal quasicrystalline phase D-Al70.83Fe9.83Ni19.34 was identified in the alloy with the highest Gibbs free energy of solid solution formation, i.e., Al71Ni24Fe5. According to this, the configurational entropy and enthalpy of solid solution formation must reach equilibrium to form quasicrystals in Al-Ni-Fe alloys. Differential thermal analysis and X-ray diffraction were used to describe the crystallization mechanism as a function of Fe concentration. Fe-57 Mossbauer spectroscopy was used to describe the Fe local environment in crystalline alloys and quasicrystals. Moreover, the influence of quasicrystalline phases on improving the corrosion resistance was investigated. Quasicrystalline Al71Ni24Fe5 alloy had a six-times lower corrosion rate than its crystalline counterparts. Although this alloy showed the best corrosion resistance, all high-pressure cast Al-Fe-Ni alloys displayed improved corrosion resistance. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The compositions of Al-Ni-Fe alloys were determined based on thermodynamic parameters optimization, with the formation of quasicrystals requiring equilibrium of configurational entropy and enthalpy in solid solution formation. The Fe concentration affected the crystallization mechanism, and Fe local environment was described by Mossbauer spectroscopy. Quasicrystalline phases were found to significantly improve corrosion resistance in the alloys studied.