23.6+Alloys

Alloys are chemical compounds containing more than one element that as a whole possess the properties of a metal. The formation of alloys is the main way to manipulate the properties of specific pure metals. There are three main classifications of alloys, those being solution alloys, heterogeneous alloys, and intermetallic compounds, each differing slightly from the others while still maintaining the general concept of an alloy being a mixture of more than one element and behaving like a metal.
 * Alloys General Info:**

Solution alloys are homogeneous mixtures of two different elements. This type of alloy can be further divided into substitutional alloys and interstitial alloys. Substitutional alloys are created when solute atoms take the places of some of the solvent atoms as shown in the first image below. These alloys are usually composed of two metallic elements with very similar atomic radii and bonding patterns. Interstitial alloys are formed when the second element fits in the interstitial spaces between the atoms of the first element. This second element must be a good bit smaller than the first in order to fit in the small spaces, because of this it is usually a nonmetal. An interstitial alloy is shown in the second image below.
 * Solution Alloys:**



The defining difference between heterogeneous alloys and solution alloys is that the heterogeneous alloys do not contain an even distribution of the multiple elements throughout the substance. The other important thing to note is that these distribution patterns are temperature dependent, or dependent on how rapidly the alloy is cooled from its molten form.
 * Heterogeneous Alloys:**

Intermetallic compounds are homogeneous mixtures like the solution alloys, however, they have definite characteristics and compositions. The atoms of these compounds are arranged in fixed, orderly, lattice structures. These structures generally increase the stability of the material as well as its melting point, but also make it more brittle. Some examples are shown in the images below.
 * Intermetallic Compounds:**




 * Related Links:**
 * [|Shape memory alloys]**
 * [|Solution Alloy]**


 * Sources:**
 * Brown, Theodore L., and H. Eugene LeMay. Chemistry: The Central Science. Upper Saddle River, NJ: Pearson Prentice Hall, 2008. Print.
 * "Solid Solution Alloys." University of Limerick. Web. 22 March 2011. <__http://www.ul.ie/~walshem/fyp/Solid%20solution.htm__>.
 * "Shape Memory Alloys and Their Applications." Stanford University. Web. 22 March 2011. <__http://www.stanford.edu/~richlin1/sma/sma.html__>.