Alloys on the other hand are man-made materials. You make them by combining a metallic element with something else. Alloys can involve combining a metal with metals, non-metals, or both.
Cast iron is a great example of a non-metal alloy (which is a little misleading, because all alloys have “metal” – it’s referring to the second or added ingredient). The iron is a mixture of iron and carbon. It can range from having about 2-3% carbon. (Learn more about cast iron and wrought iron here!)
Alloys also sometimes get fun names! Like Alnico, an alloy of iron, aluminum, nickel, cobalt, copper and/or titanium. Some of their names are an amalgamation of the names of the alloying agents. Other times they just become so popular that they get their own more “every day” sounding name, like wrought iron.
You can truly find alloys everywhere. In fact, they may be more common than their pure “metal” cousins.
You’ll find them in dental fillings (amalgam), guitar pickups (alnico), posing as musical instruments or doorknobs (brass), as jewelry (white gold), as artwork (bronze statues), in cars and planes (duralumin), on guns (gunmetal), inside electronics (solder), inside nuclear power plants (magnox), holding up buildings (steel), and even on your dining room table (pewter)!
There are more than 160 different known alloys!
Metal Alloy Structures
When metal is magnified through an electron microscope, the atoms appear in a crystalline lattice structure. Also in this structure are alloying agents. Typically, there are two types of alloy structures: substitution alloys and interstitial alloys. Substitution alloys occur if the atoms of an alloying agent replace the atoms of a main metal. Interstitial alloys on the other hand, occur when allots form due to the alloying agents becoming smaller than the main metal.