A contribution to the Al–Ni–Cr phase diagram

Abstract

The Al-Ni-Cr phase diagram was specified at 1000 • C and partially at 900 • C. The results concerning the region below 60 at.% Al agreed qualitatively with the literature data. The binary Al-Cr phases and ␥ dissolve up to ∼1 and ∼3 at.% Ni, respectively, and Al 3 Ni 2 up to ∼2.5 at.% Cr. Two ternary phases were revealed: hexagonal (a ≈ 1.77, c ≈ 1.24 nm) in a wide range between Al

Reaction Scheme and Liquidus Surface in the Al-Rich Section of the Al-Cr-Ni System

“…(a) The phase s 1 , having the crystal structure reported by Sato et al, [11] is found to have an extended homogeneity range ( Figure 1) closely matching the data of Grushko et al [12] for 900°C. The XRD profile refinements show that the lattice parameters vary little but systematically with composition (Table I).…”

“…This phase was labeled e, because it was found to have lattice parameters virtually identical to the reportedly binary phase e-CrAl 4. [13][14][15] This phase did not occur at 900°C, but Grushko et al [12] mentioned the existence of two more ternary phases at lower temperatures without giving further details.…”

“…For the remaining, more Al-rich part of the system, however, only the exploratory work of Rosell-Laclau et al [9,10] and the crystal structure determination of the ternary phase j-Al 76.2 Cr 18.0 Ni 5.8 (space group P6 3 , a = 1.7674 nm, and c = 1.2516 nm by Sato et al [11] ; in the following labeled s 1 ) existed until Grushko et al [12] reported isothermal sections for 1000°C and 900°C. At both temperatures, the ternary phase f (=s 1 ) exists as single phase over a wide composition range.…”

Investigation of Electrical Resistivity of Ni-Cr-Al Alloys in Liquid and Solid State

“…The results of research [7] indicate the presents of alloys of more complex composition. Thus, combinational manifold of atomic clusters of the Ni-Cr-Al system indicates their considerable disequilibrium and inhomogeneity.…”

“…The diagram approach used in the structural-phase analysis of alloys is developed for binary systems including Ni-Cr and Ni-Al systems [3,4]. As for ternary systems, the Ni-Cr-Al system in particular, the interest in research in this area is insignificant and the published results are few in number but they come into notice [5][6][7].…”