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

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 Al3Zr phase from the melt. The structural analysis showed that phases containing Ni and Fe, such as Al19Ni5Y3, Al10Fe2Y, and Al23Ni6Y4, 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 Al80Zr5Ni5Fe5Y5 alloys and the complete amorphization of Al85Ni5Fe5Y5 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 Al2O3 and Y2O3 layer on the surface.

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

“…The ingots were consisted of the following phases: α-Al, Al 3 Y, and Al 10 Fe 2 Y. The same phase composition was also confirmed in the literature for Al 80 Fe 10 Y 10 (induction melted) [24] and Al 82.71 Y 11.22 Fe 6.07 (prepared by arc-melting) alloys [25]. The XRD patterns of Al 88 Y 8 Fe 4 and Al 88 Y 7 Fe 5 ribbons showed broad diffraction lines as well as sharp peaks corresponding to the following crystalline phases: α-Al, Al 3 Y, Al 3 FeY 2 , Al 7 Fe 5 Y, and Al 13 Fe 4 .…”

“…The Al 10 Fe 2 Y formed dendritic structures, which are especially visible for the alloys Al 88 Y 8 Fe 4 ( Figure 3 a) and Al 88 Y 7 Fe 5 ( Figure 3 b). In the work [ 24 ] for the Al 80 Fe 10 Y 10 alloy, the same phases were identified, however, there was a greater proportion of Al 3 Y and Al 10 Fe 2 Y phases. The paper proposes a crystallization mechanism based on the differential thermal analysis (DTA) cooling curves.…”

“…3a) and Al 88 Y 7 Fe 5 (Figure 3b). In the work [24] for the Al 80 Fe 10 Y 10 alloy, the same phases were identified, however, there was a greater proportion of Al To identify the detailed structure of Al88Y6Fe6 alloy, the HRTEM examinations were carried out in the ribbon sample in as-cast state (Figure 4). Selected area electron diffraction (SAED), presented in Figure 4b, confirmed the presence of α-Al, Al13Fe4, and Al3FeY2 phases in the studied ribbon.…”

Structure and Magnetic Properties of Thermodynamically Predicted Rapidly Quenched Fe85-xCuxB15 Alloys

“…The thermodynamic approach was recently proposed and validated for different alloys based on the Fe, Fe-Co, and even Al to avoid this situation. Interestingly, this approach can obtain information about the formation of amorphous and quasicrystalline phases and crystallization from the liquid state, avoiding numerous experiments [13][14][15]. Three thermodynamics parameters, configurational entropy (∆S config ), Gibbs free energy of amorphous phase formation (∆G amorph ), and Gibbs free energy of mixing (∆G mix ), were calculated according to the Equations ( 2)-(4) (for more details and explanations, see [15]):…”

Microstructure and corrosion behavior of Al95−xNixY5 (x = 7,10) glassy ribbons

“…At t e ¼ 0, the Ni 2p peaks with x ¼ 7 and 10 are much lower than the peak at other t e (Fig. 7a(2) and b(2)), similar to the Al-Zr-Ni-Fe-Y glassy ribbon, 20 indicating that Ni oxide is very sparse on the ribbon surface. The Y 3d spectra are located at the range of E ¼ 164-153 eV and have 4 peaks, corresponding to Y 0 3d 3/2 , Y 0 3d 5/2 , Y I 3d 3/2 , and Y I 3d 5/2 (Fig.…”