A calorimetric study of alloy formation in Au-Cu and An-In systems

A calorimetric study of alloy formation in Au-Cu and Au-In systems was carr ied out. The heats of mixing, Delta H-mix, were measured at 1380, 1484 and 1604 K for Au-Cu and at 1387, 1449 and 1505 K for Au-In in the full concent ration range. The results of experiments were described by approximating eq uations. Observed values of Delta H-mix were discussed using the phase diag rams of the systems. It was shown that the systems become closer to the ide al state with increasing temperature. From the experimental data, the depen dencies of the enthalpies of the systems on the composition and temperature were estimated. The simultaneous effects of composition and temperature on enthalpy are represented in 3D diagrams. The specific heats of the alloys, in the temperature range of experiments, were derived from the slopes of e nthalpy planes.