Eutectoid vs. Eutectic

Difference Between Eutectoid and Eutectic

Eutectoidadjective

Describing the phase-change reaction of an alloy in which, on cooling, a single solid phase transforms into two other solid phases.

Eutecticadjective

Describing the chemical composition or temperature of a mixture of substances that gives the lowest temperature at which the mixture becomes fully molten. A further requirement is that that temperature is lower than the melting point of any of the pure component substances.

Eutectoidnoun

An alloy of a composition that undergoes the eutectoid transformation.

Eutecticadjective

(chemistry) Describing the thermodynamic equilibrium conditions where a liquid coexists with two solid phases.

For a mixture with two components at a fixed pressure, the eutectic reaction can only happen at a fixed chemical composition and temperature, called the eutectic point.