Comparative simulation study of the structure of the plastic zone produced by nanoindentation

Using molecular-dynamics simulation, we study nanoindentation in fcc (Cu and Al) and bcc (Fe and Ta) metals by a spherical indenter and investigate the size of the plastic zone generated. We find that while it does not strongly depend on crystal structure, surface orientation, and indentation parame...

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Detalles Bibliográficos
Autores: Gao, Yu, Ruestes, Carlos Javier, Tramontina Videla, Diego Ramiro, Urbassek, Herbert M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/50113
Acceso en línea:http://hdl.handle.net/11336/50113
Access Level:acceso abierto
Palabra clave:Dislocation Density
Dislocations
Molecular Dynamics
Nanoindentation
Pile-Up
Plastic Zone
Plasticity
Descripción
Sumario:Using molecular-dynamics simulation, we study nanoindentation in fcc (Cu and Al) and bcc (Fe and Ta) metals by a spherical indenter and investigate the size of the plastic zone generated. We find that while it does not strongly depend on crystal structure, surface orientation, and indentation parameters, the extent of the plastic zone is substantially larger before the retraction of the indenter. After retraction, the results are in good agreement with available published data. Plasticity develops by the generation, propagation and reaction of dislocations; they fall into two groups, those that adhere to the indentation pit, and those that have been emitted either into the substrate interior or glide along the surface. The total length of the dislocation network generated roughly follows available geometrical estimates; results for individual surface orientations may, however, differ quite strongly. The radial distribution of the dislocations attached to the indentation pit is computed; as a rule it shows a maximum at some depth below the indentation pit.