Interaction of a dislocation pileup with {332} tilt grain boundary in bcc metals studied by MD simulations
The sustainability and capacity of macroscopic deformation by polycrystalline metals and metallic alloys is controlled by the propagation of dislocation-mediated slip through grains. In this paper, the interaction of a pileup of 1/2¿111¿ dislocations with the {332} tilt grain boundary (GB) is studie...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/346611 |
| Acceso en línea: | https://hdl.handle.net/2117/346611 https://dx.doi.org/10.1103/PhysRevMaterials.5.013605 |
| Access Level: | acceso abierto |
| Palabra clave: | Metals--Plastic properties--Mathematical models Molecular dynamics Grain boundary Dislocation pileup Disconnection Plastic deformation Metalls -- Propietats plàstiques Àrees temàtiques de la UPC::Enginyeria dels materials::Materials compostos Àrees temàtiques de la UPC::Enginyeria dels materials::Metal·lúrgia |
| Sumario: | The sustainability and capacity of macroscopic deformation by polycrystalline metals and metallic alloys is controlled by the propagation of dislocation-mediated slip through grains. In this paper, the interaction of a pileup of 1/2¿111¿ dislocations with the {332} tilt grain boundary (GB) is studied as a function of temperature in three bcc metals: iron (Fe), chromium (Cr), and tungsten (W). The interaction results in the transformation of the crystal dislocation into GB dislocations. The {332} tilt GB absorbs the crystal dislocations of the pileup, neither the transmission nor reflection of dislocations was observed. The reaction product at the GB is determined by the crystallography of the GB and the features of the crystal dislocations involved, specifically, the orientation of the Burgers vector and the glide plane of the dislocation. In general, the decomposition results in the formation of a sessile GB dislocation with a riser that facets the GB and several elementary disconnections that glide away. In some cases, the riser increases its length with the number of dislocations absorbed and a new asymmetrical grain boundary of {112}/{110} type is created. For a given external shear stress, the number of dislocations absorbed depends on the orientation of the Burgers vector, glide plane of the pileup, and material. |
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