What is an 'alloy'?

Also see

 * 1) Useful metals
 * 2) Cupronickel (also known as copper-nickel)
 * 3) Depleted uranium
 * 4) Tungsten carbide (chemical formula: WC)
 * 5) Tungsten-steel
 * 6) Thoriated magnesium (AKA- Mag-Thor)
 * 7) Minerals and fuel in central Africa
 * 8) Mineral mining, smelting and shipping videos
 * 9) What is 'galvanizing'
 * 10) Minerals and fuel in central Africa
 * 11) Mineral mining, smelting, processing and shipping videos!
 * 12) Today's OTL types of economies, societies and regimes