ABSTRACT
This chapter talks about the main fundamentals of microstructure and phase transformations. Phase diagrams give us valuable information about the melting points of each alloying constituent. The fundamental term 'phase' is a homogeneous part of a system that has the same chemical and physical properties. The microstructure is specified by the number of phases, their proportions and their arrangement in space. Equilibrium phase diagrams give the relationship of composition of a solution as a function of temperatures and the quantities of phases in equilibrium. The time to achieve equilibrium may be so long that a state that is not at an energy minimum may have a long life and appear to be stable. A binary alloy may be: a single solid solution, essentially pure components, two separated solid solutions, a chemical compound, and together with a solid solution.
