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The partial and the integral enthalpies of mixing of liquid ternary Al-Cr-Ni alloys have been determined by high temperature iso-peribolic calorimetry at 1718-1731 K. Measurements for ternary alloys were performed along 4 isopleths with X Cr :X Ni of 0.20:0.80, 0.50:0.50, 0.70:0.30, and 0.85:0.15. The results were analytically described by the thermodynamically adapted power series according to the Kohler interpolation geometry as well as by the regular association model using the parameters for the constituent binaries and assuming that ternary association reactions with the stoichiometry Al 2 Cr 1 Ni 1 take place in the liquid state. The results were also compared with the calculated ones using the database for the Al-Cr-Ni system. The Gibbs energy of mixing of liquid and undercooled liquid Al-Cr-Ni alloys were estimated in the whole composition range. The latter function demonstrates that the minimum (-41.5 kJ.mol -1 ) shows up near the ternary composition Al 0.48 Cr 0.04 Ni 0.48 .

The partial and the integral enthalpies of mixing of liquid Al–Ni–Zr alloys and liquid Al–Cu–Ni–Zr alloys have been measured by high temperature calorimetry at 1565±5 K. A least square treatment of the data results in the following relationships (kJ mol−1): for Al–Ni–Zr Δ H=α Al–Ni x Al x Ni +α Ni–Zr x Ni x Zr +α Al–Zr x Al x Zr +α Al–Ni–Zr x Al x Ni x Zr α Al–Ni =−129.6−331.6x Al +331.0x Al 2 α Ni–Zr =−83.1−217.8x Ni +419.9x Ni 2 −1195.2x Ni 3 +810.6x Ni 4 α Al–Zr =−177.1−170.0x Zr +230.0x Zr 2 α Al–Ni–Zr =−1955.9+5842.2x Zr +4620.5x Al −3760.2x Zr 2 −2399.9x Al 2 −5964.0x Zr x Al for the quasiternary cut Al–Cu0.63Ni0.37–Zr Δ H= Δ H Cu 0.63 Ni 0.37 x Al +α Cu 0.63 Ni 0.37 –Al x Al x+α Cu 0.63 Ni 0.37 –Zr x x Zr +α Al–Zr x Al x Zr +α Al–Cu 0.63 Ni 0.37 –Zr x Al x x Zr with x=x Cu 0.63 Ni 0.37 Δ H Cu 0.63 Ni 0.37 =2.7 α Cu 0.63 Ni 0.37 –Al =−132.4−132.8x Al +197.4x Al 2 α Cu 0.63 Ni 0.37 –Zr =−64.2−181.1x+539.1x 2 −575.5x 3 α Al–Zr =−177.1−170.0x Zr +230.0x Zr 2 α Al–Cu 0.63 Ni 0.37 –Zr =−531+2020.3x Zr +3079.0x Al −832.8x Zr 2 −2749.7x Al 2 −5530.1x Zr x Al The ΔH(α(x)) relations of the enthalpy show the existence of essential contributions of ternary and quaternary interactions among the alloy components. The excess entropy and Gibbs energy of mixing are estimated on the basis of the ΔH-values data using an empirical relation. The results confirm that the liquid Al–Cu–Ni–Zr alloys exhibits near the ternary composition Al0.42Ni0.42Zr0.16 the strongest tendency toward chemical short-range ordering.