A Calorimetric Study of Heats of Mixing of Nickel or Cobalt Alloys

Abstract

The isothermal calorimeter previously reported was improved particularly by changing the heating system to the molybdenum winding heater. These improvements made it possible to measure the heats of mixing of nickel or cobalt alloys at 1450 to 1550°C under a controlled gas atmosphere.
It was also observed that so called “Newton's law of cooling” was applicable to the calibration of the calorimeter at such higher temperature.
The maximum heats of mixing of the Ni-Cu and the Co-Cu systems were 1035 and 2310 cal/g·atom, respectively. And the Ni-Cu system is considered to be the regular solution. The heats of mixing of theNi-Co system were very small, and this system could be treated as an ideal solution.
The errors of those heats of mixing were estimated approximately as ±15%.