Exploration of Multicomponent Phase Diagrams and Evaluation of Calphad Databases

Abstract

Abstract:  With the emergence of modern materials such as high-entropy alloys (HEAs) and the ever-increasing demand for improvement in conventional metallic materials, it becomes essential to have multicomponent phase diagrams. The availability of such diagrams, however, is very scarce. Calphad (CALculation of PHAse Diagram) method offers a way to construct such diagrams, combining theoretical and experimental methods into appropriate computational programs. The various visualization of multicomponent diagrams, the associated advantages and compromises are reviewed in the present work with a few example calculations on CoCrFeNi and AlCoCrFeNi systems. Besides, the accuracy of the Calphad method relies mainly on the available multi-component thermodynamic databases. A few of such databases are evaluated in this work as well.

Index Terms: Phase diagrams, Calphad, Gibbs energy, Thermo-calc.