Temperature dependence of the mixing enthalpy and excess heat capacity in the liquid system nickel-zirconium

Abstract

The mixing enthalpy AH m of the liquid system Ni-Zr was measured in the Nirich range at 1916 K up to .Xzr = 0.34 at % and for the first time in the Zr-rich range at 2270 K up to -X' Ni = 0.54 at %. Using the thermodynamic-dapted power series, a composition-and temperature-dependent description of AH m was given. Furthermore, the partial differentiation of AHm(x, T) by T yielded the excess heat capacity CpX~(x, T). The existence of chemical short-range order (associate) in the vicinity of Ni7Zr2 and NiZr was shown and was discussed with reference to AHm(x, T) and CpX~(x, T) ( 1748 to 2270 K). With decreasing temperature, the influence of chemical short-range order tended toward the composition NiZr.

Enthalpies of formation for the Al–Cu–Ni–Zr quaternary alloys calculated via a combined approach of geometric model and Miedema theory

“…The calculated mixing enthalpies of Ni-Zr system have reasonable agreement with available experimental data [33][34]. The maximum of absolute value of the mixing enthalpy is at X Zr = 0.33 from experiment, however, but it is at X Zr = 0.45 from the present calculations.…”

Contribution to the description of the absorber rod behavior in severe accident conditions: An experimental investigation of the Ag–Zr phase diagram

“…As example, a significant variation of the mixing enthalpy at the liquid state with temperature was highlighted by Rosner-Kuhn et al [37] in the NieZr system. They explained it by a possible Zr side reaction between the NieZr liquid (35 at.% Zr) and the alumina crucible.…”

“…Regarding the AleZr studies at high temperature (Table 4) Sudavtsova et al [28] likely addressed the best this problem by using yttrium oxide crucibles, which are known to be stable versus such types of melts [38]. The other determinations were performed in alumina crucibles but at much lower Zr concentration in comparison with the NieZr studies reported by RosnerKuhn et al [37]. In addition, it was shown by Arpshofen et al [39] in the NieZr system that x Zr < 0.4 in the melt was the necessary condition at 1500 Ce1600 C to prevent interaction with alumina.…”

Thermodynamic Modeling of the Undercooled Liquid in the Ni&ndash;Zr System

“…The mixing enthalpies in the liquid have been studied at 1565 K, 19) 1784 K, 22) 1838 K, 22) 1916 K, 23) 1963 K, 24) and 2270 K. 23) At low temperatures, the formation enthalpy of amorphous alloys was measured by Turchanin et al, 25) Spit et al 26) and Henaf et al 27) where there measurements are not in agreement. The formation enthalpy reported by Truchanin et al 25) is a more negative result and in this case the amorphous phase would be more stable than the intermetallic compounds.…”

“…In the present assessment, the driving force starts to deviate from the linear relationship at around 1300 K and gradually decreases, due to the formation of the associate as the temperature decreases. 1565K [19] 1740K [22] 1838K [22] 1916K [23] 1963K [24] 2270K [23] Present work 1565K 2270K 5)…”