<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (June 2007) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (June 2007) (Learn how and when to remove this template message) </Td> </Tr> <P> Microstructure is the very small scale structure of a material, defined as the structure of a prepared surface of material as revealed by a microscope above 25 × magnification . The microstructure of a material (such as metals, polymers, ceramics or composites) can strongly influence physical properties such as strength, toughness, ductility, hardness, corrosion resistance, high / low temperature behavior or wear resistance . These properties in turn govern the application of these materials in industrial practice . Microstructure at scales smaller than can be viewed with optical microscopes is often called nanostructure, while the structure in which individual atoms are arranged is known as crystal structure . The nanostructure of biological specimens is referred to as ultrastructure . A microstructure's influence on the mechanical and physical properties of a material is primarily governed by the different defects present or absent of the structure . These defects can take many forms but the primary ones are the pores . Even if those pores play a very important role in the definition of the characteristics of a material, so does its composition . In fact, for many materials, different phases can exist at the same time . These phases have different properties and if managed correctly, can prevent the fracture of the material . </P>

The crystal structure of a material is generally examined by