Study of the enthalpies of formation and crystallization in the system Zr-Ni

Abstract

Articles you may be interested inOn the atomic structure of Zr-Ni and Zr-Ni-Al metallic glasses

Thermodynamic Modeling of the Undercooled Liquid in the Ni–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.…”

“…29) There are numerous measurements of both latent heats of crystallization from the undercooled liquid. 27,[30][31][32][33][34][35] In the case of the Ni-Zr alloys, it is difficult to measure the glass transition temperature, which it was not detected on the DSC heating curve. 29,36) Altounian et al 34) have pointed out that higher heating rates are required to observe the glass transition because the enthalpy change of the transition is much smaller than that of the crystallization.…”

Crystallization of Zr-Ni metallic glasses

“…Altounian et al [8] and Henaff et al [13] have presented AH data as a function of composition for the Zr-Ni system. Assuming that the enthalpy change on crystallization is almost entirely a change in internal energy between the glass and the crystalline phases, Altounian et al concluded that the AH curve could provide a guide to the crystalline phase diagram [8].…”

“…In that study evidence was found for the presence of two types of short-range order in the amorphous state, indicating that phase separation occurs in this composition range in the Zr-Ni system. Several other researchers have studied crystallization in this system in recent years and have reported data from thermal analysis which were in some cases conflicting [3][4][5][6][7][8][9][10][11][12][13]. All these researchers conducted their studies on melt-spun ribbons which are prone to contamination from the spinning atmosphere or from the crucible material during melting [14].…”

Thermodynamic Analysis of the Phase Equilibria in the Nb-Ni-Zr System

“…In this binary system, the phase boundaries have been investigated over the entire composition range by Kirkpatrick and Larsen,32) and for the Ni-rich region by Bsenko 33) 35,36) and the enthalpy of formation for the compound phases [37][38][39][40] have been reported. A critical assessment of this binary system has been carried out by Nash and Jayanth, 41) and a thermodynamic assessment has been reported by Saunders. 42) Ghosh 43) has performed a thermodynamic reassessment of this binary system, taking into account the formation of Ni 3 Zr and Ni 11 Zr 9 , and the homogeneity range of Ni 5 Zr and Ni 10 Zr 7 , which were excluded by Saunders.…”