The Y–Ni–Cu ternary system at
600°C
Chem.
Met. Alloys 9 (2016)
1-10
https://doi.org/10.30970/cma9.0315
Oksana MYAKUSH, Volodymyr BABIZHETSKYY, Volodymyr LEVYTSKYY, Bogdan KOTUR
The isothermal section of the Y–Ni–Cu phase
diagram at 600°C has been investigated by means of X-ray diffraction and
microstructure analyses. The homogeneity ranges of the solid solutions YNi5‑õCuõ (0 ≤ õ ≤ 4.6) (structure type CaCu5, space
group P6/mmm a = 0.48861(2)–0.50080(4),
c = 0.39592(2)–0.40740(4) nm),
Y2Ni17‑õCuõ (0 ≤ õ ≤ 7.8) (structure type
Th2Ni17, space group P63/mmc,
a = 0.8314(1)–0.8387(1),
c = 0.8042(1)–0.8117(1) nm),
YCu6–7Nix
(0 ≤ õ ≤ 0.28)
(structure type TbCu7, space group P6/mmm, a = 0.49470(4)–0.49540(4),
c = 0.4133(4)–0.4227(4) nm) were
refined. It was found that the maximal solubility of the third component does
not exceed 3.8 at.% in Y2Cu7
and less than 1 at.% in Y2Ni7, YCu,
and YCu4. The crystal structure of a single crystal of
composition YNi4Cu
(YNi5‑õCuõ solid solution) was
investigated by X-ray diffraction: a = 0.4899(2), c = 0.3979(3) nm, R1 = 0.028 for 57 independent reflections with Io ≥ 2σ(Io),
wR2 = 0.058. A new ternary compound, YNi2.85–0.75Cu1.15–3.25,
of unknown structure with an extended homogeneity range, was found.
Phase equilibria in
the Y–Ni–Cu system at
Keywords
Intermetallics / Rare-earth metal system / Phase
diagram / X-ray diffraction