Provision and Use of Thermodynamic Data for the Solution of High-Temperature Practical Problems

Abstract

When chemical thermodynamic calculations are applied to the evaluation of· metallurgical processes, it is essential that reliable data are used in order to reach valid conclusions. The compilation of such data from raw experimental results which are reported in the literature is a highly skilled operation. All aspects of the skills involved are described in the present article, including available methods for estimating unknown data. It is desirable that fully self-consistent data should include reliable phase diagram information when available, and the relationships between thermodynamic data and phase equilibria are described. A review is given of the current position in the calculation of phase equilibria for multicomponent alloy systems, employing data from binary systems. The storage of data in computer data banks is discussed and the particular NPL data bank which stores metallurgical thermodynamic data is described. Finally, a review of recent examples in which thermodynamic calculations have been applied to practical problems is given.