A superalloy contains large amounts of alloying elements intended to produce a combination of high strength at elevated temperatures, and resistances to creep. Superalloy nickels are used in jet engines, heat treatment equipment, and gas turbines because of their high temperature strength, and creep resistance. The symmetry of the nanocrystalline film can be seen on opposite sides of the crack. Also a symmetry is apparent normal to the crack plane. Contained in the picture above are grains, grain boundaries, dislocations, and vaccancies.
Grains are the crystalline regions of a solid.
Randomly oriented grains exhibit isotropic material properties. The grain boundaries in between the grains act as strengthening mechanisms for the metal. As dislocations move through the lattice under load, the grain boundaries will restrict their movement increasing the strength of the material. Vacancies can be seen and are usually a function of temperature. The selected section was chosen because of its variety of lattice features.