Metallic alloys are important for a variety of products in many industries. Several thousand standard alloys are currently in use and new ones with better performance are developed all the time to meet new demands. For example, there are multiple alloys of steel and aluminum which are used to build automobiles, trucks, planes, and trains.
When exploiting alloys, it is important to understand their properties which are related to the composition and microstructure. The microstructure - phases, grains, or inclusions - has a significant effect on tensile strength, elongation, and both thermal and electrical conductivity.
Understanding well the relationship between the composition, microstructure, and macroscopic properties is important for the design and manufacture of alloys. Grains are crystallites (microscopic crystals) which form in alloys during the cooling stage of production.