Relationship Between the Thermodynamic Parameters, Structure, and Anticorrosion Properties of Al-Zr-Ni-Fe-Y Alloys

Abstract

Abstract The influence of the chemical composition on the crystallization process, amorphous phase formation, and the anticorrosion properties of Al-Zr-Ni-Fe-Y alloys are presented. To reduce the number of experiments, a thermodynamic approach was applied in which the entropy and Gibbs free energy of representative alloys were optimized. The low glass-forming ability of Al-Zr-Ni-Fe-Y alloy systems was related to the crystallization of the Al 3 Zr phase from the melt. The structural analysis showed that phases containing Ni and Fe, such as Al 19 Ni 5 Y 3 , Al 10 Fe 2 Y, and Al 23 Ni 6 Y 4 , played a key role in the formation of amorphous alloys. According to this, the simultaneous addition of Ni/Fe and Y is important to prevent the crystallization of Al-based alloys in the melt. The formation of an amorphous phase in Al 80 Zr 5 Ni 5 Fe 5 Y 5 alloys and the complete amorphization of Al 85 Ni 5 Fe 5 Y 5 alloys were responsible for the high corrosion resistance compared with fully crystalline alloys. Moreover, the addition of Y had a significant impact on the anticorrosion properties. The XPS results showed that the alloys tended to form a passive Al 2 O 3 and Y 2 O 3 layer on the surface.