Interface between crystallites in a polycrystalline material
Micrograph of a polycrystalline metal; grain boundaries evidenced by acid etching.Differently-oriented crystallites in a polycrystalline material
In materials science, a grain boundary is the interface between two grains, or crystallites, in a polycrystalline material. 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] On the other hand, grain boundaries disrupt the motion of dislocations through a material, so reducing crystallite size is a common way to improve mechanical strength, as described by the Hall–Petch relationship.
^Lehockey, E. M.; Palumbo, G.; Lin, P.; Brennenstuhl, A. M. (1997-05-15). "On the relationship between grain boundary character distribution and intergranular corrosion". Scripta Materialia. 36 (10): 1211–1218. doi:10.1016/S1359-6462(97)00018-3. ISSN 1359-6462.
^Raj, R.; Ashby, M. F. (1971-04-01). "On grain boundary sliding and diffusional creep". Metallurgical Transactions. 2 (4): 1113–1127. Bibcode:1971MT......2.1113R. doi:10.1007/BF02664244. ISSN 1543-1916. S2CID 135851757.
materials science, a grainboundary is the interface between two grains, or crystallites, in a polycrystalline material. Grainboundaries are two-dimensional...
science, grain-boundary strengthening (or Hall–Petch strengthening) is a method of strengthening materials by changing their average crystallite (grain) size...
Grainboundary sliding (GBS) is a material deformation mechanism where grains slide against each other. This occurs in polycrystalline material under...
known as grainboundaries. Crystallite size in monodisperse microstructures is usually approximated from X-ray diffraction patterns and grain size by other...
area of grainboundary. The term is commonly used in metallurgy but is also used in reference to ceramics and minerals. The behaviors of grain growth is...
diffusion from grainboundary – atom from grainboundary diffuses through lattice grainboundary diffusion – atoms diffuse along grainboundary plastic deformation...
occurs when a crack propagates along the grainboundaries of a material, usually when these grainboundaries are weakened. The more commonly seen transgranular...
and a sliding of the grainboundaries. Robert L. Coble first reported his theory of how materials creep across grainboundaries and at high temperatures...
creating physical barriers from second phase precipitates forming along grainboundaries. There are five main strengthening mechanisms for metals, each is a...
Microstructural defects: Pores and crystallites tend to have straight grainboundaries following higher density planes. Cleavage: This typically occurs preferentially...
which reduces the grainboundary energy and results in better grainboundary cohesion and ductility. Another form of grainboundary strengthening is achieved...
grainboundaries. The other process involves differences in stored strain energy between neighboring grains, resulting in migration of existing grain...
weighted average of the grainboundary diffusion coefficient and the lattice diffusion coefficient. Diffusion along both the grainboundary and in the lattice...
The grainboundary diffusion coefficient is the diffusion coefficient of a diffusant along a grainboundary in a polycrystalline solid. It is a physical...
because an increase in grainboundary area results in increased grainboundary sliding. Chandross & Argibay modeled grainboundary sliding as viscous flow...
form in the grainboundaries of stainless alloys. This chemical reaction robs the material of chromium in the zone near the grainboundary, making those...
and a grainboundary. Like a grainboundary, a twin boundary has different crystal orientations on its two sides. But unlike a grainboundary, the orientations...
and local grainboundary bulging, and measuring recrystallized grain size. The nucleation process is triggered at boundaries of existing grains only when...
possible mechanism for producing mechanical weakness is grainboundary sliding, where grains slide slightly past each other under stress, lubricated by...
the defects, such as grain-boundaries (GB) and vacancies, present in the system and the average grain-size. Graphene grainboundaries typically contain heptagon-pentagon...
elastic-plastic zone boundary, and then link back to the main crack tip. This is usually a mixture of cleavages of grains, and ductile fracture of grains known as...
chromium carbide results in reduced corrosion resistance along the grainboundary leaving the stainless steel susceptible to unanticipated corrosion in...
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