Phase Diagrams Flashcards
Define a binary isomorphous system
Complete solubility of the solute into the solvent
No solubility limit
How does the solidifying process of pure metals differ from alloys?
Pure metals melt/solidify at a single temperature
Alloys melt/solidify at a range of temperatures
How do you determine the composition of a phase in a phase diagram?
Draw a tie line. The composition of each phase is where the line crosses the solubility lines.
How do you determine the fraction of the phases?
The lever rule
How does non equilibrium cooling effect the development of the microstructure in a binary isomorphous system?
It shifts the solidus line down and creates a cored microstucture of different compositions.
How can coring be reduced?
Heat treatment to diffuse the material.
Define a terminal solid solution.
A solid solution that extends to either of the pure components.
Define an intermediate solid solution.
A solid solution that does not extend to either of the pure components.
Define an intermetallic compound.
A compound of two metals with a distinct chemical formula, displayed as a line on a phase diagram.
Define an invariant reaction.
A reaction at one point on a phase diagram.
Define the eutectic reaction.
The reaction of L a +b
Define a eutectoid reaction
One solid being formed by two different solids
g a+b
Define a peritectic reaction.
A solid formed by a different solid and liquid
a L+b
What is a congruent phase transformation. An incongruent phase transformation?
Congruent happens at the same composition, (C L) incongruent changes the composition of at least one phase. (L a+b)
