W–Ni–Co ternary system thermodynamic description at intermediate temperatures
Résumé
Tungsten heavy alloy (W–Ni–Co) samples of different compositions were prepared by powder
metallurgy (solid liquid sintering), heat treated at 1000°C and subsequently analyzed. The isothermal
section at 1000°C is more complex than expected since a new intermetallic phase appears to be
stable (D0a structure - Cu3Ti prototype). Formation enthalpies associated with the new phase were
obtained through ab initio calculations. Both data are currently used to develop a new CALPHAD
modelization of the W-Ni-Co system