Substitutional Alloy

Definition

A substitutional alloy is a type of alloy where the atoms of the component metals are about the same size so they can replace each other in the crystal lattice.

Related terms

Brass:

An example of a substitutional alloy made primarily from copper and zinc. The similar atomic sizes allow them to substitute for each other in the lattice structure.

Sterling Silver: Another example which consists mainly of silver with small amounts copper substituted into its crystal lattice structure.

Gold Karat System: This system measures purity based on substitution. 24-karat gold is pure, while 18-karat gold is only 75% gold with the rest being other metals substituted into the lattice.