Alloy

Alloy is a  metallic substance that composed of two or more elements, as either a compound or a solution atleast one of them metal.

Almost all metals are used as alloy and it is mixtures of several element because these have properties superior to pure metals.

Examples of alloys including  stainless steel, brass, bronze, white gold, and sterling silver. The principal alloying elements for steel are chromium, nickel, manganese, molybdenum, silicon, tungsten, vanadium, and boron. Some metal alloys are naturally occurring and require little processing to be converted into industrial grade materials. Ferro-alloys such as Ferro-chromium and Ferro-silicon, for instance, are produced by smelting mixed ores and are used in the production of various steels.

Over 90% of metal used is in the form of alloys. Alloys are used because their chemical and physical properties are superior for an application than that of the pure element components. Typical improvements include corrosion resistance, improved wear, special electrical or magnetic properties, and heat resistance. Alloys are used because they retain the key properties of component metals are less expensive.

The components of alloys cannot be separated using a physical means. An alloy is homogeneous and retains the properties of a metal, even though it may include metalloids or nonmetals in its composition.


Reference
 https://www.thebalance.com/metal-alloys-2340254
https://www.thoughtco.com/alloy-definition-examples-and-uses-606371
https://www.britannica.com/technology/alloy
https://en.wikipedia.org/wiki/Alloy