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 YNi_5‑хCu_х (0 ≤ х ≤ 4.6) (structure type CaCu₅, space group P6/mmm a = 0.48861(2)–0.50080(4), c = 0.39592(2)–0.40740(4) nm), Y₂Ni_17‑хCu_х (0 ≤ х ≤ 7.8) (structure type Th₂Ni₁₇, space group P6₃/mmc, a = 0.8314(1)–0.8387(1), c = 0.8042(1)–0.8117(1) nm), YCu_6–7Ni_x (0 ≤ х ≤ 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 (YNi_5‑хCu_х 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 I_o ≥ 2σ(I_o), wR₂ = 0.058. A new ternary compound, YNi_2.85–0.75Cu_1.15–3.25, of unknown structure with an extended homogeneity range, was found.

Phase equilibria in the Y–Ni–Cu system at 600°C

Keywords

Intermetallics / Rare-earth metal system / Phase diagram / X-ray diffraction