http://www.ck12.org Chapter 3. Chemical Interactions
3.11 Alloys
- Define alloy.
- Describe examples of alloys.
Metals such as iron are useful for many purposes because of their unique properties. For example, they can conduct
electricity and bend without breaking. However, pure metals may be less useful than mixtures of metals with other
elements. For example, adding a little carbon to iron makes it much stronger. This mixture is called steel. Steel is
so strong that it can hold up huge bridges, like the one pictured above. Steel is also used to make skyscrapers, cargo
ships, cars, and trains. Steel is an example of an alloy.
What Are Alloys?
Analloyis a mixture of a metal with one or more other elements. The other elements may be metals, nonmetals,
or both. An alloy is formed by melting a metal and dissolving the other elements in it. The molten solution is
then allowed to cool and harden. Alloys generally have more useful properties than pure metals. Several examples
of alloys are described and pictured below. You can learn about another alloy—the amazing alloy called memory
wire—at the following URL. If you have braces on your teeth, you might even have this alloy in your mouth!
http://www.youtube.com/watch?v=LSNRwtTMH6w
Examples of Alloys
Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in
theFigure3.19.