Al-Gd-V (Aluminum-Gadolinium-Vanadium)

Recently, [2011Zha] determined an isothermal section for this ternary system at 500 °C.

Binary Systems

The Al-Gd system [2003Cac, Massalski2] has the following intermediate phases: Al₃Gd (D0₁₉, Ni₃Sn-type hexagonal), Al₂Gd (C15, MgCu₂-type cubic), AlGd (ErAl-type orthorhombic), Al₂Gd₃  (Al₂Zr₃-type tetragonal), and AlGd₂ (C23, Co₂Si-type orthorhombic). The Al-V phase diagram [2004Gon, Massalski2] depicts five intermetallic compounds: Al₈V₅  (D8₂, Cu₅Zn₈-type cubic), Al₃V (D0₂₂, TiAl₃-type tetragonal), Al₂₃V₄ (hexagonal), Al₄₅V₇ (monoclinic), and Al₂₁V₂ (cubic). There are no intermediate phases in the Gd-V system [Massalski2].

Ternary Isothermal Section

With starting metals of 99.99% Al, 99.9% Gd and 99.9% V, [2011Zha] arc-melted a number of alloys, which were homogenized and given a final anneal at 500 °C for 240 h and quenched in liquid nitrogen. The phase equilibria were studied with x-ray powder diffraction and scanning electron microscopy with energy dispersive analysis. Two ternary compounds Al₄₃V₄Gd₆  (Al₄₃Mo₄Ho₆-type hexagonal with lattice parameters of a = 1.0996 nm and c = 1.7813 nm; denoted τ₁ here) and Al₂₀V₂Gd (Al₂₀Cr₂Ce-type cubic with a = 1.456 nm; denoted τ₂) were found. The isothermal section constructed by [2011Zha] at 500 °C is shown in Fig. 1. The binary compounds Al₂Gd₃, AlGd and Al₂Gd show a solubility of 1-2 at.% V. The other binary compounds do not show any ternary solubility.

Fig. 1

Al-Gd-V isothermal section at 500 °C [2011Zha]. Narrow two-phase regions are omitted