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The microstructure that results when a metal of eutectic composition solidifies.
(physical chemistry)
An alloy or solution that has the lowest possible constant melting point.



a liquid system that, at a given pressure, is in equilibrium with solid phases whose number is equal to the number of components of the system. The liquid system may be a solution or a melt. According to the phase rule, the solidification of a eutectic system occurs at constant temperature, as does the solidification of pure substances. Hence, upon solidification, a eutectic mixture of solid phases having the same composition is formed. For a given system, the melting point of the eutectic mixture is lower than the melting point of a mixture of any other composition.

The eutectic reaction is characteristic of both metallic and non-metallic systems whose components are completely soluble in one another in the liquid state but are only partly soluble or insoluble in the solid state (seeBINARY SYSTEMS and TERNARY SYSTEM). In the phase diagram of a binary eutectic system whose components are not soluble in one another in the solid state (see Figure 1), the liquidus lines TAE and TBE of the pure components A and B, respectively, intersect at E, which is called the eutectic point. At E, the liquid L is simultaneously saturated in both components.

Figure 1. Phase diagram of a binary eutectic system whose components are not soluble in one another in the solid state: (FEG) eutectic-temperature line

In engineering, eutectics are widely used as, for example, casting alloys and solders. Cryohydrates, which are eutectic aqueous salt systems, are often used as freezing mixtures.


Bochvar, A. A. Issledovanie mekhanizma i kinetiki kristallizatsii splavov evtekticheskogo tipa. Moscow-Leningrad, 1935.
Anosov, V. Ia., M. I. Ozerova, and Iu. Ia. Fialkov. Osnovy fiziko-khimicheskogo analiza. Moscow, 1976.


References in periodicals archive ?
The three alternative eutectic systems investigated, namely the Al-Ni eutectic, the Al-Fe eutectic and the Al-Ni-Fe eutectic, exhibit very good casting ability and tensile properties at both room temperature and elevated temperature; and in this regard, they compare favorably with the Al-Si eutectic.
These eutectic ILs have some superior characters in the preparation procedure exhibited as following; firstly, the preparation procedure of these eutectic mixtures is very simple, only needs to mix two different compounds mechanically and requires no medium; secondly, 100% reaction mass efficiency and zero emission in the synthesis are achieved, and which is relatively environmentally benign.
Significantly, while its competitors sell through distributors, who also stock consumables of other companies, Castolin Eutectic alloys are primarily sold direct through its own associated companies who can identify new repair subcontract opportunities.
In cast aluminum alloys, casting flaw and microstructure features such as porosity, oxides, eutectic particles and dendrite cell and grain structures are not uniform in the entire stressed volume.
The system has been chosen because it is a simple, purely eutectic, binary system used in solder applications.
The characteristics of the eutectic arrest were significantly modified by lanthanum and cerium additions of up to 1.
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The 3500-III is capable of performing automated eutectic die attach utilizing backside metalized die or preforms, and enables bonding of thin die with air bridges using 2 or 4 sided perimeter collets.
LONDON, June 7 /PRNewswire/ -- The 2009 Frost & Sullivan Award for Product Market Growth Leadership is presented to Castolin Eutectic.
The results of fluidity tests are normally scattered, and although a large standard deviation emerged in this examination, a clear trend emerged showing that fluidity improved with increased aluminum content in the hypoeutectic regime, reached the maximum values at the eutectic composition and gradually decreased as aluminum content increased further in the hypereutectic regime.
Reflow temperatures are higher, time above the higher reflow temperatures is different, appearance of the joint has considerably changed, and the need for process control is even greater than it was for eutectic solders.
To deliver high-speed rewriteable performance, Verbatim BD-RE media is produced with a technology based on Super Eutectic Recording Layer (SERL) technology, the proprietary phase-change recording layer technology developed by MKM and proven in Verbatim's earlier DVD+RW and DVD-RW media.