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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.
English: Wentworth grain size chart from United States Geological Survey Open-File Report 2006-1195, “Surficial sediment character of the Louisiana offshore continental shelf region: A GIS Compilation” by Jeffress Williams, Matthew A. Arsenault, Brian J. Buczkowski, Jane A. Reid, James G. Flocks, Mark A. Kulp, Shea Penland, and Chris J. Jenkins
Grain boundaries are two-dimensional defects in the crystal structure, and tend to decrease the electrical and thermal conductivity of the material. Most grain boundaries are preferred sites for the onset of corrosion [1] and for the precipitation of new phases from the solid. They are also important to many of the mechanisms of creep. [2]
Figure 1: Hall–Petch strengthening is limited by the size of dislocations. Once the grain size reaches about 10 nanometres (3.9 × 10 −7 in), grain boundaries start to slide. In materials science, grain-boundary strengthening (or Hall–Petch strengthening) is a method of strengthening materials by changing their average crystallite (grain ...
In metallurgy, materials science and structural geology, subgrain rotation recrystallization is recognized as an important mechanism for dynamic recrystallisation.It involves the rotation of initially low-angle sub-grain boundaries until the mismatch between the crystal lattices across the boundary is sufficient for them to be regarded as grain boundaries.
Because grains usually have varying crystallographic orientations, grain boundaries arise. While undergoing deformation, slip motion will take place. Grain boundaries act as an impediment to dislocation motion for the following two reasons: 1. Dislocation must change its direction of motion due to the differing orientation of grains. [4] 2.
In materials science, segregation is the enrichment of atoms, ions, or molecules at a microscopic region in a materials system. While the terms segregation and adsorption are essentially synonymous, in practice, segregation is often used to describe the partitioning of molecular constituents to defects from solid solutions, [1] whereas adsorption is generally used to describe such partitioning ...
The pile-up of dislocations at grain boundaries and Orowan loops around strong precipitates are two main sources of these back stresses. When the strain direction is reversed, dislocations of the opposite sign can be produced from the same source that produced the slip-causing dislocations in the initial direction.