Definitions
Alloy - a pure metal to which other elements have been added
Components - the elements which make up an alloy
Phase - a region of material with uniform physical and chemical properties often represented by a Greek symbol (e.g. ?-Iron)
Composition - the percentage of each element in the alloy, usually by weight (wt%)
The constitution of the alloy is described by the overall composition, the number of phases, their composition and proportions