Al-Ce-Zr (Aluminum-Cerium-Zirconium)

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Phase Diagram Evaluations: Section II

Al-Ce-Zr (Aluminum-Cerium-Zirconium) V. Raghavan

An isothermal section of this ternary system at 500 °C was determined by [2010Hu], which depicts no ternary compounds.

Binary Systems The Al-Ce phase diagram was reassessed thermodynamically by [2005Gao], using new experimental results as additional input. The intermediate phases in this system are: aCe3Al (D019, Ni3Sn-type hexagonal), bCe3Al (L12, AuCu3-type cubic), Ce2Al (stable between 775 and 648 °C; Co2Si-type orthorhombic?), CeAl (CeAl-type orthorhombic), CeAl2 (C15, MgCu2-type cubic), aCeAl3 (Ni3Sn-type hexagonal), bCeAl3 (stable between 1192 and 973 °C), CeAl4 or bCe3Al11 (D13, Al4Ba-type tetragonal), and aCe3Al11 (aCe3La11-type orthorhombic). The Al-Zr phase diagram [Massalski2] depicts ten intermediate phases: ZrAl3 (D023-type tetragonal), ZrAl2 (C14, MgZn2-type hexagonal), Zr2Al3 (Zr2Al3-type orthorhombic), ZrAl (Bf, CrB-type orthorhombic), Zr5Al4 (Ga4Ti5-type hexagonal), Zr4Al3 (Ir4Al3-type hexagonal), Zr3Al2 (Zr3Al2-type tetragonal), Zr5Al3 (D8m, W5Si3-type tetragonal), Zr2Al (B82, Ni2In-type hexagonal), and Zr3Al (L12, AuCu3-type cubic). There are no intermediate phases in the Ce-Zr system [Massalski2].

Fig. 1 Al-Ce-Zr isothermal section at 500 °C [2010Hu]. Narrow two-phase regions are omitted

is in line with the binary results. No ternary phases were found. The solubility of the third component in the binary compounds is less than 1 at.%.

Ternary Isothermal Section With starting metals of 99.99% purity, [2010Hu] arcmelted under Ar atm 53 alloys. The alloys were given a final anneal at 500 °C for 350 h and quenched in liquid nitrogen. The phase equilibria were studied with scanning electron microscope equipped with energy dispersive analyzer, x-ray powder diffraction and differential thermal analysis. The isothermal section at 500 °C constructed by [2010Hu] is shown in Fig. 1. The high-temperature binary compounds Zr5Al3, Zr5Al4 and Ce2Al were not found at 500 °C, which

References 2005Gao: M.C. Gao, N. Unlu, G.J. Shiflet, M. Mihalkovic, and M. Widom, Reassessment of Al-Ce and Al-Nd Binary Systems Supported by Critical Experiments and First-Principles Energy Calculations, Metall. Mater. Trans. A, 2005, 36A, p 3269-3279 2010Hu: Z. Hu, Y. Zhan, J. She, Y. Du, and H. Xu, Phase Equilibria in the Al-Zr-Ce System at 773 K, J. Alloys Compd., 2010, 491, p 200-202

Journal of Phase Equilibria and Diffusion Vol. 31 No. 6 2010

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