Journal of Alloys and Compounds 364 (2004) 164–170 An investigation of the Al–Pd–Fe phase diagram between 50 and 100 at.% Al: phase equilibria at 900–1020 ◦ C S. Balanetskyy a,b , B. Grushko a,∗ , E. Kowalska-Strz¸ eciwilk a,1 , T.Ya. Velikanova b , K. Urban a a Institut für Festkörperforschung, Forschungszentrum Jülich, D-52425 Jülich, Germany b I.N. Frantsevich Institute for Problems of Materials Science, 03680 Kiev 142, Ukraine Received 22 May 2003; accepted 28 May 2003 Abstract The Al–Pd–Fe alloy system exhibits a continuous range between the solid solution of b.c.c. Fe extending at 1000 ◦ C up to 53 at.% Al and congruent AlPd. At higher Al concentrations three ternary cubic phases designated C, C 1 and C 2 and orthorhombic O–Al 13 (Fe,Pd) 4 were revealed. The Al–Pd orthorhombic ε-phases dissolve up to ∼10 at.% Fe and exhibit ε 16 and ε 22 structural variants in addition to ε 6 and ε 28 typical of binary compositions. Al 13 Fe 4 dissolves < 1.0 at.% Pd, Al 5 Fe 2 up to 3.9 at.% Pd, Al 2 Fe up to 1.4 at.% Pd, Al 3 Pd 2 up to 1.1 at.% Fe. Partial isothermal sections are presented for 1020, 995, 975 and 900 ◦ C. © 2003 Elsevier B.V. All rights reserved. Keywords: Transition metal alloys; Intermetallics; Phase diagram; TEM; X-Ray diffraction 1. Introduction Al–Pd–Fe belongs to a group of alloy systems exhibit- ing formation of quasicrystals and phases with associated periodic structures. According to the position of Fe in the periodic table this alloy system is related to the exten- sively studied Al–Pd–Mn ([1] and references therein) and Al–Pd–Co [2]. While Al–Pd–Mn contains stable icosahe- dral and decagonal phases, only metastable decagonal phase was revealed in Al–Pd–Co [3]. On the other hand, stable decagonal phases are known in Al–Ni–Fe [4] and Al–Ni–Ru [5]. In contrast to the above-mentioned alloy systems, the literature data on Al–Pd–Fe are significantly poorer. Formation of a stable high-temperature Al 75 Pd 15 Fe 10 decagonal quasicrystalline phase was reported in Ref. [6] and of low-temperature one-dimensional quasicrystalline phases of the same composition in Ref. [7]. In Ref. [8] the formation of a metastable Al 70 Pd 17 Fe 13 icosahedral phase was also mentioned. A stable cubic phase of Al 70 Pd 10 Fe 20 ∗ Corresponding author. Tel.: +49-2461-612-399; fax: +49-2461-616-444. E-mail address: b.grushko@fz-juelich.de (B. Grushko). 1 On leave from the Institute of Physics and Chemistry of Metals, University of Silesia, 40007 Katowice, Poland. composition and a lattice parameter ∼2.05 nm was reported in Ref. [9]. At about the same time, the Al-rich part of the Al–Pd–Fe phase diagram was independently investigated [10]. The 500 ◦ C isothermal section determined in this work did not contain ternary compounds. According to this work, the Al–Fe and Al–Pd -phases form a continuous compositional range, Al 3 Pd 2 extends towards about Al 3 Fe (old designation of Al 13 Fe 4 [11]) up to about 15 at.% Fe and Al 4 Pd extends towards about Al 3 Fe up to about 10 at.% Fe. These results are significantly different from the earlier report of these au- thors (cited in Ref. [12]) where the binary phases exhibit only small extensions and the Al–Fe and Al–Pd -phases are split by a wide miscibility gap, Al 3 Fe is in equilibrium with Al 3 Pd (designated Al 8 Pd 3 by the authors) and Al 3 Pd 2 while in Ref. [10] the Al 3 Pd phase is in equilibrium with Al 3 Fe and Al 5 Fe 2 . In Ref. [10] the Al 3 Fe is mentioned as having an orthorhombic structure with the lattice parame- ters of a = 1.5696, b = 0.8166 and c = 4.8226 nm but not a monoclinic structure as accepted in Ref. [11]. In view of this disagreement, the Al-rich part of Al–Pd–Fe was reinvestigated [13]. The latter study did not confirm the formation of either stable quasicrystals or the above- mentioned cubic phase, but revealed three other ternary cubic compounds designated C 1 (P 23, a≈1.55 nm, at Al 69 Pd 21 Fe 10 ), C 1 ′ (Pm 3, a = 0.7654 nm, in Al 73 Pd 17 Fe 10 ) 0925-8388/$ – see front matter © 2003 Elsevier B.V. All rights reserved. doi:10.1016/S0925-8388(03)00609-1