Phase relations in the Cu-poor part of the Ce–Al–Cu system at 503 K

The phase relations of the ternary system Ce–Al–Cu in the Cu-poor part at 503 K were investigated by X-ray powder diffraction (XRD). The investigated composition region consists of 16 single-phase, 32 two-phase and 17 three-phase regions. At 503 K, the maximum solid solubilities of Cu in Al, α-Ce3Al11, CeAl3 and CeAl2 are about 2.5 at.%, 1.6, 3.6 and 5.3, respectively, and Al in CeCu5 is about 39.2 at.%. The homogeneity ranges of Al2Cu and AlCu phases extend from about 32.1 to 32.6 at.% Cu and 49.7 to 52.4 at.% Cu, respectively. Five ternary compounds and their solid solutions have been observed in this work: CeAl12−xCux (4.0 ≤ x ≤ 4.52), Ce2Al17−xCux (6.50 ≤ x ≤ 7.55), CeAl13−xCux (6.62 ≤ x ≤ 6.92), CeAl4−xCux (0.74 ≤ x ≤ 1.10) and CeAlCu.