Al-Er-V (Aluminum-Erbium-Vanadium)

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Section II: Phase Diagram Evaluations

Al-Er-V (Aluminum-Erbium-Vanadium) V. Raghavan

Recently, an isothermal section at 500 °C was reported for this ternary system by [2010Yan]. It depicts the previously-known ternary compound Al43Er6V4.

Binary Systems The Al-Er phase diagram [Massalski2] depicts the following intermediate phases: Al3Er (L12, AuCu3-type cubic), Al2Er (C15, MgCu2-type cubic), AlEr (AlEr-type

orthorhombic), Al2Er3 (Zr3Al2-type tetragonal), and AlEr2 (C23, Co2Si-type orthorhombic). The Al-V phase diagram [2004Gon, 2010Yan, Massalski2] depicts five intermetallic compounds: Al8V5 (D82, Cu5Zn8-type cubic), Al3V (D022, TiAl3-type tetragonal), Al23V4 (hexagonal), Al45V7 (monoclinic), and Al10V (cubic). There are no intermediate phases in the Er-V system. Here, a liquid miscibility gap is present with a monotectic reaction at 1870 °C.

Ternary Isothermal Section With starting metals of 99.99% Al, 99.99% Er and 99.9% V, [2010Yan] arc-melted under Ar atm 58 binary and ternary alloys. The alloys were given a final anneal at 500 °C for 240 h and quenched in liquid nitrogen. The phase equilibria were studied with optical and scanning electron microscopy and x-ray powder diffraction. The isothermal section constructed at 500 °C by [2010Yan] is shown in Fig. 1. The ternary compound Al43Er6V4 (denoted s; Al43Ho6Mo4type hexagonal, Pearson symbol hP106, space group P63/mcm, lattice parameters a = 1.08967 nm and c = 1.76236 nm) is present. The Al-Er compounds Al2Er, AlEr and Al2Er3 dissolve up to about 1-2 at.% V. The solubility of the third component in the other binary compounds is negligible.

References

Fig. 1 Al-Er-V isothermal section at 500 °C [2010Yan]. Narrow two-phase regions are omitted

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2004Gon: W. Gong, Y. Du, B. Huang, R. Schmid-Fetzer, C. Zhang, and H. Xu, Thermodynamic Reassessment of the Al-V System, Z. Metallkd., 2004, 95(11), p 978-986 2010Yan: Z. Yan, Y. Zhan, H. Mo, Y. Du, and H. Xu, Determination of the Phase Equilibria in the Al-Er-V Ternary System at 773 K, J. Alloys Compd., 2010, 503, p 61-64

Journal of Phase Equilibria and Diffusion Vol. 32 No. 1 2011

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