The metallurgical procedure in which alloys are most often created during the molten stage of a metal, and the alloying element is usually added during the refinement process: Creating alloys involves combining a base metal with at least one other element, that can be metallic or non-metallic, in order to produce a new material

Steel is made by introducing carbon from the coke used in the refinement of iron ore.

Alloys are also divided into ferrous (iron based) and non-ferrous, in which the base is usually copper, aluminum, or titanium.