An amalgam is an alloy that contains mercury, which is a soft liquid metal. Dental amalgams are mixtures of mercury, silver, and zinc. These metals are used because they are soft and can be kneaded into the cavity, while the chemical reactions that go on in your mouth harden them. These amalgams are more commonly known as fillings. Most metallic objects are manufactured from alloys.
Steel is an alloy of carbon with other metals.
Steel production is greater than that of any other alloy. Aluminum alloys are the second largest group of alloys produced. Aluminum alloys are used to manufacture products as different as food wrap and airplanes. Since the 1980's, aluminum-lithium alloys have become very important. Lithium is the lightest metal known, so alloys of this type are lightweight, yet very strong.