Application of calorimetry and DTA to metal systems

The calorimetric methods employed for the study of metal systems (solution, combustion, direct reaction calorimetry) are considered and briefly discussed with respect to each other.The development of apparatus for the calorimetry of metals and alloys is examined as a whole, with particular reference to the progressive increase of the maximum limit of the working temperature.The employment of calorimetric methods for the determination of equilibrium phase diagrams is described according to two different approaches: (1) corresponding to classical DTA, based on the identification of phase boundaries by the exploration of the system as a function of temperature, at constant composition; (2) corresponding to the measurement of partial and integral enthalpies of alloy formation as a function of the composition, at constant temperature.A brief report is given of the utilization of calorimetric data for the computation of equilibrium phase diagrams and equations are also given that allow the equilibrium temperature to be calculated between a liquid solution (binary or multicomponent) and a pure component (or an intermetallic compound) as a function of the thermodynamic parameters obtained by calorimetric methods.