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The energy of a tilt boundary and the energy per dislocation as the misorientation of the boundary increases The energy of a low-angle boundary is dependent on the degree of misorientation between the neighbouring grains up to the transition to high-angle status.
Grain boundary engineering involves manipulating the grain boundary structure and energy to enhance mechanical properties. By controlling the interfacial energy, it is possible to engineer materials with desirable grain boundary characteristics, such as increased interfacial area, higher grain boundary density, or specific grain boundary types.
In materials science, grain growth is the increase in size of grains (crystallites) in a material at high temperature.This occurs when recovery and recrystallisation are complete and further reduction in the internal energy can only be achieved by reducing the total area of grain boundary.
This is the earliest theory specifically for grain boundaries, in which McLean [3] uses a model of P solute atoms distributed at random amongst N lattice sites and p solute atoms distributed at random amongst n independent grain boundary sites. The total free energy due to the solute atoms is then: = + [ (!!) ()!! ()!
Grain boundary sliding (GBS) is a material deformation mechanism where grains slide against each other. This occurs in polycrystalline material under external stress at high homologous temperature (above ~0.4 [1]) and low strain rate and is intertwined with creep.
Subgrains are defined as grains that are oriented at a < 10–15 degree angle at the grain boundary, making it a low-angle grain boundary (LAGB). Due to the relationship between the energy versus the number of dislocations at the grain boundary, there is a driving force for fewer high-angle grain boundaries (HAGB) to form and grow instead of a ...
Grain boundary areas contain those atoms that have been perturbed from their original lattice sites, dislocations, and impurities that have migrated to the lower energy grain boundary. Treating a grain boundary geometrically as an interface of a single crystal cut into two parts, one of which is rotated, we see that there are five variables ...
This is also known as intercrystalline fracture or grain-boundary separation. More rapid diffusion along grain boundaries than along grain interiors; Faster nucleation and growth of precipitates at the grain boundaries; Quench cracking, or crack growth following a quenching process, is another example of intergranular fracture and almost always ...