Display the equilibrium phases which occur as a function of temperature and composition.
a) Apply the phase rule (P + F = C + 2) for a two component alloy. How many phases can be in equilibrium for various degrees of freedom (temperature, pressure and/or phase composition)?
b) In most cases, the formation of the equilibrium phases (ex: L ? a, a ? a + b) is temperature and time dependent. Briefly explain this statement in terms of the concepts of nucleation, growth, and "C" curve behavior.
c) In some temperature - time transformations, a metastable phase is produced. Explain what we mean by a metastable phase and give an example of how such a phase can be formed.