Computational Thermodynamics

In order to fulfill all the requirements under service conditions, modern alloys have to be based on very complex multi-component systems, where simplifying assumptions can no longer be made. The thermodynamic properties — which control driving forces, boundary conditions, and kinetic parameters — are complex functions of temperature and chemical composition. Computational approach has emerged and established itself as the most efficient way of designing and studying complex, modern alloys.

The CALPHAD method is based of the fact that a phase diagram is a representation of the thermodynamic properties of a system. Thus, if the thermodynamic properties are known, it would be possible to calculate the multi-component phase diagrams. Thermodynamic descriptions of lower order systems (e.g., the Gibbs energy of each phase) are combined to extrapolate higher order systems.

Finally, the expense of conducting experiments in materials science or metallurgical engineering is often prohibitively high. In many cases, using the experimental route to solve complex metallurgical problems can be more time-consuming and costly for a particular company than they are worth. The cost-benefit picture, however, changes if such problems could be solved numerically (sometimes in just a couple of hours) using computational tools such as Thermo-Calc, DICTRA, JMatPro, FactSage, Pandat, MTDATA, etc.