by Jenny Knodell, IQS Editor
Almost all the metals we use today—silver, aluminum, brass, even steel—are alloys, a homogenous mix of a metal and one or more other substances that enhances or changes its properties. In fact, very few metals are actually put to use in their pure form. From ancient times till now, humans have been experimenting and engineering alloys so they exhibit certain properties for thousands of years. There are literally an infinite number of combinations, all resulting in very different structural properties. In a way, metals and elements team up, work together and pool their strengths to make different metallic substances. Alloys may be a homogenous solid solution, a heterogeneous mix of tiny crystals or a true chemical compound.
The very first alloy was bronze, used appropriately, during the Bronze Age. It’s a simple formula: 90% copper 10% tin = a stronger, more chemically resistant metal that can be slightly changed to make musical instruments, weapons and currency. The steel alloy formula is iron and a little bit of carbon, and this simple mixture makes by far the most commonly used metal, often considered the building block of modern society. Gold is alloyed with copper, aluminum, nickel and silver to give jewelry different colored tints, as well as create less expensive alternatives like 18k yellow gold.
Old bronze coins. Ring made of green and rose gold.
Alloying allows metals to become harder, softer, more chemically and erosion resistant, more or less electrically conductive, have a higher or lower melting point, different colors, textures, densities, and perhaps most importantly, lighter weight. If it wasn’t for the Wright Brothers and their ingenious idea to build their engine out of an ultra light aluminum alloy, air planes would never have taken flight. As you can see, we would be stuck in the Stone Age if metallurgists never got creative. In fact, it’s the never ending search for lighter and lighter metal alloys that lead to space exploration and improvements in automotive and mass transportation. Today, scientists are coming up with new and improved alloys that replace outdated existing metals and allow for technological advances.
A few years ago, a titanium-based alloy was created in an automotive lab that had ultra high strength and super elasticity. It was created by using quantum mechanics and its properties are unparalleled by any other metal or alloy to date. This alloy, along with others made in the same lab, plan to serve the space program to be used on satellites, deep space probes and shuttles as springs and other instruments. Last year a nickel-tungsten alloy, developed by an MIT professor, promises to replace chrome, the shiny protective coating applied to car bumpers and bathroom faucets. Chrome has been used for over half a century, and works very well, but its manufacturing process is dangerous and polluting. The new alloy looks identical to chrome and exhibits all of its same properties, but is more durable and safer to produce.
Titanium alloy spring. Nickel-tungsten chrome replacement.
Who knows what the future holds for alloy development. Some scientists predict that eventually, we’ll be able to create alloys that can detect when they’ve been damaged and are able to fix themselves. They seem to have infinite possibilities, and we can only wait and see what new alloys hold in store.