BackgroundMicrostructure refers to the arrangement of atoms in an orderly, repetitive three-dimensional pattern. The microstructure of a metal is closely linked to its quality, composition, processing history and properties. Metals are typically polycrystalline where they are composed of many grains. The grains generally cannot be seen and therefore require a microscope to see them clearly. Apart from the grain boundaries, the crystalline structure of the material remains the same. Microstructures are characterized by their arrangement, their proportions and the number of phases present. For alloys, their microstructures also depend on what the alloy is made of, the concentration of the components and the heat treatment of the alloy. Eutectic structures are characterized by alternating layers. For ferrocarbon alloys, common microstructures can be pearlite, spheroidite, bainite, and martensite and are composed of varying amounts of ferrite and cementite. Ferrite has a BCC crystalline structure and is the stable form of iron. Cementite is the intermediate compound that forms a 6.7 ...