Carburize

Part of speech: verb

Definitions

1. to chemically treat steel or iron by introducing carbon into its surface layer to increase hardness
2. to enhance the surface hardness of metal through carbon absorption or diffusion
3. to impregnate the outer portion of ferrous metal with carbon to improve its strength and wear resistance

Etymology: Carburize is a technical coinage built from "carbon" and the suffix "-ize," which turns a noun into a verb meaning "to treat with or cause to become." The verb is essentially a metallurgist's shorthand for the older process of case hardening, in which iron or steel was packed in charcoal and heated so that carbon diffused into the surface, leaving a hard outer skin over a tougher core. The process itself is much older than the word. Blacksmiths and armourers were doing versions of it for centuries before anyone had a name for carbon as an element, since the charcoal supplied the carbon without them needing to understand the chemistry. The term came into use in English in the 19th century, when industrial metallurgy began describing these methods precisely. The noun "carbon" itself was coined by Antoine Lavoisier in the 1780s from Latin "carbo," meaning charcoal or ember, which is why the word for this element still points back to the fuel that did the work.