FACTOID # 1: Idaho produces more milk than Iowa, Indiana and Illinois combined.

 Home Encyclopedia Statistics States A-Z Flags Maps FAQ About

 WHAT'S NEW

SEARCH ALL

Search encyclopedia, statistics and forums:

(* = Graphable)

Encyclopedia > Eutectic point

A eutectic or eutectic mixture is a mixture of two or more phases at a composition that has the lowest melting point, and where the phases simultaneously crystallise from molten solution at this temperature. The proper ratios of phases to obtain a eutectic is identified by the eutectic point on a phase diagram. The term comes from the Greek 'eutektos', meaning 'easily melted.' In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... The melting point of a solid is the temperature at which it changes state from solid to liquid. ... In physical chemistry and materials science, a phase diagram is a type of graph used to show the equilibrium conditions between the thermodynamically-distinct phases. ...

The phase diagram at right displays a simple binary system composed of two components, A and B, which has a eutectic point. The phase diagram plots relative concentrations of A and B along the X-axis, and temperature along the Y-axis. The eutectic point is the point at which the liquid phase borders directly on the solid α + β phase (A solid phase composed of both A and B), representing the minimum melting temperature of any possible alloy of A and B. The temperature that corresponds to this point is known as the eutectic temperature. Image File history File links Binary phase diagram of eutectic alloy This image created by me, Bryan Antman, on November 19, 2004. ... Temperature is also the name of a song by Sean Paul. ... A liquid will assume the shape of its container. ... Look up Phase in Wiktionary, the free dictionary Phase may refer to: Phase (matter), a physically distinctive form of a substance, such as the solid, liquid, and gaseous states of ordinary matter Phase (waves), the time position (or angle in the complex plane) within a cycle of a periodic waveform... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ...

Not all binary system alloys have a eutectic point: those that form a solid solution at all concentrations, such as the gold-silver system, have no eutectic. A binary phase diagram displaying solid solutions over the full range of relative concentrations. ... General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ... General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ...

Solid products of a eutectic transformation can often be identified by their lamellar structure, as opposed to the dendritic structures commonly seen in non-eutectic solidification. The same conditions that force the material to form lamellae can instead form an amorphous solid if pushed to an extreme. Lamellar structures or microstructures are composed of fine, alternating layers of different materials in the form of lamellae. ... A crystal dendrite is a crystal that develops with a typical multi-branching tree-like form. ... An amorphous solid is a solid in which there is no long-range order of the positions of the atoms. ...

## Contents

The term is often used in metallurgy to describe the alloy of two or more component materials having the relative concentrations specified at the eutectic point. When a non-eutectic alloy freezes, one component of the alloy crystallizes at one temperature and the other at a different temperature. With a eutectic alloy, the mixture freezes as one at a single temperature. A eutectic alloy therefore has a sharp melting point, and a non-eutectic alloy exhibits a plastic melting range. The phase transformations that occur while freezing a given alloy can be understood using the phase diagram by drawing a vertical line from the liquid phase to the solid phase on a phase diagram; each point along the line describes the composition at a given temperature. Metallurgy is a domain of materials science and of materials engineering that studies the physical and chemical behavior of metallic elements, their intermetallic compounds and their mixtures, which are called alloys. ... An alloy is a combination, either in solution or compound, of two or more elements, at least one of which is a metal, and where the resulting material has metallic properties. ... Crystal (disambiguation) Insulin crystals A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ...

Some uses include:

(De)soldering a contact from a wire. ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ... General Name, Symbol, Number lead, Pb, 82 Chemical series poor metals Group, Period, Block 14, 6, p Appearance bluish white Atomic mass 207. ... General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ... General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ... Aluminum is a soft and lightweight metal with a dull silvery appearance, due to a thin layer of oxidation that forms quickly when it is exposed to air. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... Cast iron usually refers to grey cast iron, but can mean any of a group of iron-based alloys containing more than 2% carbon (alloys with less carbon are carbon steel by definition). ... Iron-carbon phase diagram, showing the conditions under which austenite (Î³) is stable in carbon steel. ... Cementite or iron carbide is a chemical compound with the formula Fe3C, and an orthorhombic crystal structure. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... Brazing is a joining process whereby a non-ferrous filler metal and an alloy are heated to melting temperature (above 450Â°C / 800Â°F) and distributed between two or more close-fitting parts by capillary action. ... Woods metal is a fusible alloy that becomes liquid at approximately 70 Â°C. It is a eutectic alloy of bismuth, lead, tin, and cadmium with the following percentages by weight: 50% Bi, 26. ... Fields metal, or Fields alloy, is a fusible alloy that becomes liquid at approximately 62 Â°C (144 Â°F). ... This typical sprinkler head will spray water into the room if sufficient heat reaches the bulb and causes it to shatter. ... General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery white Atomic mass 200. ... Galinstan is an eutectic alloy of gallium, indium, and tin which is liquid at room temperature, typically freezing at -20 Â°C (-4 Â°F). ... An amorphous metal is a metallic material with a disordered atomic-scale structure. ... Corrosion, atmospheric and biologic (Barnacles) Corrosion is deterioration of intrinsic properties in a material due to reactions with its environment. ... General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Atomic mass 22. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Atomic mass 39. ... NaK is an alloy of sodium and potassium, and particularly one that is liquid at room temperatures. ... A coolant, or heat transfer fluid, is a fluid which flows through a device in order to prevent its overheating, transferring the heat produced by the device to other devices that utilize or dissipate it. ... A fast neutron reactor or simply a fast reactor is a category of nuclear reactor in which the fission chain reaction is sustained by fast neutrons. ...

## Other eutectic mixtures

Sodium chloride and water form a eutectic mixture. It has a eutectic point of -21.2 C[1] and 23.3%[2] salt by weight. The eutectic nature of salt and water is exploited when salt is spread on roads to aid snow removal, or mixed with ice to produce low temperatures (for example, in traditional ice cream making). Sodium chloride, also known as common salt, table salt, or halite, is a chemical compound with the formula NaCl. ... Water (from the Old English waeter; c. ... A sidewalk clearing plow in Ottawa, Canada Snow removal is the job of removing snow after a snowfall to make travel easier and safer. ... Missing image Ice cream is often served on a stick Boxes of ice cream are often found in stores in a display freezer. ...

Minerals may form eutectic mixtures in igneous rocks.[3] Minerals are natural compounds formed through geological processes. ... Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ...

Some inks are eutectic mixtures, allowing inkjet printers to operate at lower temperatures.[4] Inkjet printers are a type of computer printer that operates by propelling tiny droplets of liquid ink onto paper. ...

## Other critical points

### Eutectoid

When the solution above the transformation point is solid, rather than liquid, an analogous eutectoid transformation can occur. For instance, in the iron-carbon system, the austenite phase can undergo a eutectoid transformation to produce ferrite and cementite (iron carbide), often in lamellar structures such as pearlite and bainite. This eutectoid point is at about 0.6% carbon; alloys of nearly this composition are called high-carbon steel, while those which do not undergo eutectoid transformation are termed mild steel. The process analogous to glass formation in this system is the martensitic transformation. General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... Iron-carbon phase diagram, showing the conditions under which austenite (Î³) is stable in carbon steel. ... Ferrite may refer to: (1) ferromagnetic ceramic materials, used in magnetic applications; (2) iron or iron alloys with a body centred cubic crystal structure. ... Cementite or iron carbide is a chemical compound with the formula Fe3C, and an orthorhombic crystal structure. ... Cementite or iron carbide is a chemical compound with the formula Fe3C. It is a hard, brittle component of carbon steel, with orthorhombic crystals, and forms from austenite during cooling. ... Lamellar structures or microstructures are composed of fine, alternating layers of different materials in the form of lamellae. ... Pearlite occurs at the eutectoid of the iron-carbon phase diagram (near the lower left). ... Iron-carbon phase diagram, showing the eutectoid temperature and composition, at which bainite can form. ... Martensite, named after the German metallurgist Adolf Martens, is a class of hard minerals occurring as lathe- or plate-shaped crystals. ...

Iron-carbon phase diagram, showing the euctectoid transformation between austenite (γ) and pearlite.

Image File history File links An English version of Diag phase fer carbone. ... Image File history File links An English version of Diag phase fer carbone. ... In physical chemistry and materials science, a phase diagram is a type of graph used to show the equilibrium conditions between the thermodynamically-distinct phases. ... Iron-carbon phase diagram, showing the conditions under which austenite (Î³) is stable in carbon steel. ... Pearlite occurs at the eutectoid of the iron-carbon phase diagram (near the lower left). ...

### Peritectic

Peritectic transformations are also similar to eutectic reactions. Here, a liquid and solid phase of fixed proportions react at a fixed temperature to yield a single solid phase. Since the solid product forms at the interface between the two reactants, it can form a diffusion barrier and generally causes such reactions to proceed much more slowly than eutectic or eutectoid transformations.

Three-Phase Reactions

Such a transformation exists in the iron-carbon system, as seen near the upper-left corner of the figure. It resembles an inverted eutectic, with the δ phase combining with the liquid to produce pure austenite at 1495 °C and 0.17 mass percent carbon. Image File history File links Download high resolution version (833x699, 18 KB)I created this file using paint. ... Image File history File links Download high resolution version (833x699, 18 KB)I created this file using paint. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... Iron-carbon phase diagram, showing the conditions under which austenite (Î³) is stable in carbon steel. ...

## References

1. ^ Muldrew, Ken; Locksley E. McGann (1997). "Phase Diagrams." Cryobiology - A Short Course. University of Calgary. URL accessed on 2006-04-29.
2. ^ Senese, Fred (1999). "Does salt water expand as much as fresh water does when it freezes?." Solutions: Frequently asked questions. Department of Chemistry, Frostburg State University. URL accessed on 2006-04-29.
3. ^ Fichter, Lynn S. (2000). "Igneous Phase Diagrams." Igneous Rocks. James Madison University. URL accessed on 2006-04-29.
4. ^ Davies, Nicholas A.; Beatrice M. Nicholas (1992). "Eutectic compositions for hot melt jet inks." US Patent & Trademark Office, Patent Full Text and Image Database. United States Patent and Trademark Office. URL accessed on 2006-04-29.

2006 (MMVI) is a common year starting on Sunday of the Gregorian calendar. ... April 29 is the 119th day of the year in the Gregorian calendar (120th in leap years). ... 2006 (MMVI) is a common year starting on Sunday of the Gregorian calendar. ... April 29 is the 119th day of the year in the Gregorian calendar (120th in leap years). ... 2006 (MMVI) is a common year starting on Sunday of the Gregorian calendar. ... April 29 is the 119th day of the year in the Gregorian calendar (120th in leap years). ... 2006 (MMVI) is a common year starting on Sunday of the Gregorian calendar. ... April 29 is the 119th day of the year in the Gregorian calendar (120th in leap years). ... 2006 (MMVI) is a common year starting on Sunday of the Gregorian calendar. ... April 12 is the 102nd day of the year in the Gregorian calendar (103rd in leap years). ...

## Bibliography

• Mortimer, Robert G. (2000). Physical Chemistry. Academic Press. ISBN 0125083459.
• Reed-Hill, R.E.; Reza Abbaschian (1992). Physical Metallurgy Principles. Thomson-Engineering. ISBN 0534921736.
• Easterling, Edward (1992). Phase Transformations in Metals and Alloys. CRC. ISBN 0748757414.
• Askeland, Donald R.; Pradeep P. Phule (2005). The Science and Engineering of Materials. Thomson-Engineering. ISBN 0534553966.

Results from FactBites:

 Eutectic point - Wikipedia, the free encyclopedia (818 words) A eutectic or eutectic mixture is a mixture of two or more phases at a composition that has the lowest melting point, and where the phases simultaneously crystallise from molten solution at this temperature. The proper ratios of phases to obtain a eutectic is identified by the eutectic point on a phase diagram. The eutectic point is the point at which the liquid phase borders directly on the solid α + β phase (A solid phase composed of both A and B), representing the minimum melting temperature of any possible alloy of A and B. The temperature that corresponds to this point is known as the eutectic temperature.
 Melting point - Wikipedia, the free encyclopedia (328 words) Unlike the boiling point, the melting point is relatively insensitive to pressure. In the presence of nucleating substances the freezing point of water is the same as the melting point. Melting points are often used to ascertain the purity of and to characterise organic compounds.
More results at FactBites »

Share your thoughts, questions and commentary here