Eutectic Point
From Soft-Matter
Entry by Emily Redston
Figure 1 shows a common and relatively simple binary phase diagram known as a eutectic phase diagram. A eutectic diagram can be thought of as the intersection of two solid solution diagrams. At the intersection of the two liquidus lines, the melt is in equilibrium with the two solid phases. In other words, a liquid phase is transformed into two solid phases upon cooling, and the opposite occurs upon heating. This is called a eutectic reaction, and can be written as
According to Gibbs Phase Rule, at this phase transition, we know that the number of degrees of freedom is
There is only one degree of freedom, so if we set pressure (a typical choice) then we cannot have a solidification range, and thus the melt must solitify at exactly one point --- the eutectic point! |
References
[1] Spaepen, Frans. Applied Physics 282: Solids: Structure and Defects. Harvard University
[2] Haasen, Peter. Physical Metallurgy. Cambridge: Cambridge UP, 1996.
[3] Callister, William D. Materials Science and Engineering: an Introduction. New York: John Wiley & Sons, 2007.
Keyword in References
Stretchable Microfluidic Radiofrequency Antennas
See also:
Phase separation in Phases and Phase Diagrams from Lectures for AP225.
