Glossary

A eutectic blend is a specific mixture of two or more substances—usually metals, alloys, or chemical compounds—that melts and solidifies at a single, sharply defined temperature, which is lower than the melting point of any of the individual components. This special composition is called the eutectic point, and the resulting mixture behaves almost like a pure substance in the way it melts and freezes.

In a eutectic blend, the components do not dissolve into one another to form a single uniform solid solution. Instead, when the mixture solidifies, it forms a distinct, fine-scale microstructure—often alternating layers or interlocking crystals of the individual phases. This microstructure can provide desirable properties such as improved machinability, enhanced strength, or lower melting temperature. Because eutectic mixtures melt uniformly at a single temperature rather than over a range, they are widely used in solders, brazing alloys, casting alloys, and fusible materials where precise melting behavior is important.

A classic example is the eutectic solder alloy of 63% tin and 37% lead (Sn–Pb), which melts sharply at 183°C, lower than either pure tin or pure lead. In industrial metals, eutectic structures also appear in systems like aluminum–silicon, iron–carbon (where the eutectic point produces ledeburite), and many others. Because the eutectic composition yields both predictable melting behavior and a unique microstructure, eutectic blends are critical in metallurgy, manufacturing, electronics, and materials engineering.