Alloys have been used since as early as 3000 BCE. The first known alloys were brass (Copper and Zinc) and bronze (Copper and Tin). Both of these likely originated from early metallurgical learning, where two ores of different compositions were smelted together. We will never know if the first alloys were the result of brilliance or mistake, but what followed is the entire history of metallurgy and our technological society.
Notably, the element Nickel was not isolated until the 19th Century, but its presence was felt in some Copper deposits, which, when smelted, formed cupro-nickel. These ores were often described as ‘having the devil in them’ as the Nickel content made the Copper very hard to work. Nick is an old word for the devil.
Brass and the much more serviceable bronze both alter the soft and ductile nature of Copper to deliver harder, tougher, and more resilient materials – and in the case of bronze, the ability to hold an edge. Bronze was the first weapons-grade metal, and it destroyed empires. The best bronze in ancient Europe came from Cyprus, and the Mycenaeans, Greeks, and Romans built their empires on it. Today, brass and bronze are still frequently used to create parts and components; you can find them as auto-quotable options within Xometry’s instant quoting engine.
In about 1,600 BCE, wrought iron and cast iron began to be produced. Iron is much harder to extract from the ore, and it is unlikely that it was refined by accident. We have experimental metallurgists from 4,000 years ago to thank for it. Pure iron is soft, ductile and malleable and really not of much utility. The big step comes in smelting and working the Iron with a pretty high Carbon content, to alter its structure. The first Carbon is used as a reducing agent in the smelt, so it became an alloying agent by stealth. Cast and then hot-worked (wrought) Iron displaced bronze, and empires fell.
Iron and the alloy family then remained mostly unchanged for 3,000 years, other than a few highlights:
- Adding/controlling the Carbon content became an art form. Sword makers in Toledo (which is an awesome city in Spain with great views) and Jōmon period Japan (up to 1,000 BCE) both learned to make steel, either by adding Carbon by hand (Japan) or by using wooden anvils (Toledo).
- Later on, in various regions, a kind of case hardening by quenching in Nitrogen-rich water added an extra bite to the blade.
It really wasn’t until the Industrial Revolution in the 18-19th centuries that metallurgy became a formal science, delivering many of the alloys commonly used today. Advances in chemistry allowed the isolation of metallic elements such as Manganese, Nickel, and Chromium, Aluminum, Titanium, Magnesium and other elements used in alloys today. The Industrial Revolution is one of my favorite periods of history and continues to shape our lives today.
