The scandium-ruthenium phase diagram

Thermodynamic optimization of the Ru–Sc system

“…1. The main difference with the results determined by Eremenko et al [7] is about the melting behavior of two compounds RuSc 2 and Ru 4 Sc 11 . In the present work, it is described as liq.…”

“…+ RuSc 2 → Ru 4 Sc 11 at 1403 K and liq. → Ru 4 Sc 11 + Ru 13 Sc 57 at 1343 K reported by Eremenko et al [7] and Tripathi [12]. Thus, the asymmetry of the left-and right-side liquidus of the compound Ru 13 Sc 57 disappeared.…”

“…In the present work, the phase relations and transformation temperatures are based on the phase diagram of the Ru-Sc system determined by Eremenko et al [7] and reviewed by Tripathi [12]. The enthalpy of formation of RuSc determined by Selhaoui and Kleppa [8] is given a larger weight because the enthalpies of formation for many compounds predicated by revised Miedema model of Niessen et al [10,11] are more exothermic than the experimental results reviewed by Guo and Kleppa [16].…”

“…It has the homogeneity range ∼33.3-40.0 at.% Sc [7]. In the present work, Ru 2 Sc is treated as the formula (Ru,Sc) 2 Sc by using a two-sublattice model [14,15].…”

“…It has the homogeneity range 50.0-60.0 at.% Sc [7]. In order to reflect their structural relationship between the compound RuSc (ordered, bcc B2) and the bcc terminal solution phase (disordered, bcc A2), in the present work, the two phases were modeled using the same sublattice formalism represented by (Ru,Sc) 0.5 (Ru,Sc) 0.5 .…”