Metallurgy is a term used to describe any process that involves changing the properties of a metal element. There are three main categories of metallurgy: extractive, physical and mechanical. Metallurgy is one of the most important fields of material manipulation in history: the beginning of the Bronze Age is considered to be a milestone in social evolution. This article lists some of the most important metallurgical processes.
Annealment is a kind of metallurgical process that involves the rapid heating and cooling of a metal – usually steel – in order to make it less brittle. There are many applications for malleable steel that will bend and not break. Baling wire and cable ties are both often made from annealed steel. Balingwiredirect.com, for example, is a major seller of steel wire that has been annealed. The more flexible a wire is, the less likely it is to break when tightly wound around a bale of compressed material.
Iron, and alloys that contain iron (like steel), are prone to oxidization when exposed to moisture and oxygen. This reaction – otherwise known as rusting – can seriously deteriorate the durability of a metal component. Galvanization is one of the most effective ways of preventing rust and prolonging the life of a component. During the process, steel or iron components are dipped into molten zinc that has been heated to around 450 degrees. The zinc and the iron combine to form a layer of alloy that is highly resistant to oxygenation and corrosion.
Deep drawing is a form of metallurgic shaping that is completed using a punch and a die. A high-pressure shaped punch pushes sheet metal into a shaped die.
Rolling is a kind of physical metallurgy that has been conducted since around 600 BC in the Middle East. Leonardo Da Vinci also drew up plans for a metal rolling mill in Renaissance Italy. Metal rolling involves exactly what it sounds like: sheets of milled metal are passed through a series of rollers in order to reduce thickness and increase strength. In a process known as ‘hot rolling’, the metal is heated up so that is more easily manipulated by the rollers. Rolling is essential in creating sheets of steel or iron with completely uniform properties.
Metal alloys are materials composed of two or more metallic elements. Alloys are often far stronger than their constituent elements. Steel, for instance, is an alloy that is far stronger and more corrosion-resistant than its primary element: iron. This increased strength is often down to the interactions between the atoms of each separate element. Larger atoms exert a compressive force on smaller atoms, while smaller atoms exert a tensile force.
The first alloy discovered was bronze – made by melting together copper and tin. The discovery of bronze in around 3500 BC completely changed human society. Bronze was a tough and easily workable metal that sparked massive changes in art, agriculture, warfare and human expansion. The ensuing time period is aptly known as The Bronze Age.