Editing Eutectic system (section)

===Alloys===
Eutectic [[alloy]]s have two or more materials and have a eutectic composition. When a non-eutectic alloy solidifies, its components solidify at different temperatures, exhibiting a plastic melting range. Conversely, when a well-mixed, eutectic alloy melts, it does so at a single, sharp temperature. The various phase transformations that occur during the solidification of a particular alloy composition can be understood by drawing a vertical line from the liquid phase to the solid phase on the phase diagram for that alloy.

Some uses for eutectic alloys include:
*NEMA eutectic alloy overload relays for [[power-system protection|electrical protection]] of three-phase motors for pumps, fans, conveyors, and other factory process equipment.<ref>{{cite web |url= http://www.industrial-electronics.com/output_devices_amplifiers_valves_relays_variable-frequency_drives_stepper_motors_servomotors/Operation_Overloads.html |title= Operation of the Overloads |access-date= 2015-08-05 }}</ref>
*Eutectic alloys for [[soldering]], both traditional alloys composed of [[lead]] (Pb) and [[tin]] (Sn), sometimes with additional [[silver]] (Ag) or [[gold]] (Au) — especially [[Solder alloys#Sn63Pb37|Sn{{sub|63}}Pb{{sub|37}}]] and Sn{{sub|62}}Pb{{sub|36}}Ag{{sub|2}} alloy formula for electronics - and newer lead-free soldering alloys, in particular ones composed of tin, silver, and [[copper]] (Cu) such as Sn{{sub|96.5}}Ag{{sub|3.5}}.
*Casting alloys, such as [[Silumin|aluminium-silicon]] and [[cast iron]] (at the composition of 4.3% carbon in iron producing an [[austenite]]-[[cementite]] eutectic)
*[[Silicon chip]]s are [[eutectic bonding|eutectic bonded]] to gold-plated substrates through a silicon-gold eutectic by the application of [[ultrasound|ultrasonic]] energy to the chip. 
*[[Brazing]], where diffusion can remove alloying elements from the joint, so that eutectic melting is only possible early in the brazing process
*Temperature response, e.g., [[Wood's metal]] and [[Field's metal]] for [[fire sprinkler]]s
*Non-toxic [[Mercury (element)|mercury]] replacements, such as [[galinstan]]
*Experimental [[amorphous metal|glassy metals]], with extremely high strength and [[corrosion]] resistance
*Eutectic alloys of [[sodium]] and [[potassium]] ([[NaK]]) that are liquid at room temperature and used as [[coolant]] in experimental [[Fast neutron reactor|fast neutron nuclear reactor]]s.