Phase equilibria and phase transformations

This unit will focus on the microstructure of materials, considering how the stability of different phases of materials depends on basic thermodynamic functions. Phase diagrams and the key concepts of Gibbs energy and chemical potential are used to explain the equilibrium between phases and to predict the microstructures of materials. The mechanisms of new phase formation are discussed in terms of both the driving forces and kinetics of formation, including the role of atomic diffusion. What happens when the thermodynamically stable microstructural state cannot develop is discussed and metastable microstructures are considered in detail. Throughout the unit, technologically important materials systems are used to illustrate these concepts.