A Calorimetric Study of Heats of Mixing of Liquid Iron Alloys

Fe-Cr, Fe-Mo, Fe-W, Fe-V, Fe-Nb, Fe-Ta

Abstract

Heats of mixing of liquid iron with a few metals, having higher melting point than iron (i.e., chromium, molybdenum, tungsten, vanadium, niobium or tantalum), were measured at 1600°C by the developed isoperibol calorimeter. The method for measuring the heat of mixing of a liquid metal and another solid metal was checked by comparing the heat of mixing of liquid nickel and solid iron with that of liquid nickel and liquid iron.
The experimental errors were estimated to be less than ±15% for the cases that a liquid metal was mixed with another solid metal.
Heats of mixing of binary iron alloys, for which the both reference states were liquid, were calculated by combining the present experimental results with the previously reported thermochemical properties. Mixing of liquid iron with liquid chromium, molybdenum, vanadium, niobium or tantalum was an exothermic reaction, while mixing of liquid iron-tungsten was endothermic.