Plastic deformation of a porous bcc metal containing nanometer sized voids

• Autores: Ruestes, Carlos Javier; Bringa, Eduardo Marcial; Stukowski, A.; Rodriguez Nieva, J.D.; Tang. Y.; Meyers, M. A.
• Año de publicación: 2014
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: DISLOCATIONS; MOLECULAR DYNAMICS; NANOPOROUS; NANOVOID
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Nanoporous materials, can present an outstanding range of mechanical properties. Both molecular dynamics and dislocation analysis were used to evaluate and quantify the evolution of plasticity in a porous Ta single crystal containing randomly placed voids with 3.3 nm radii and average initial porosity of 4.1%, when subjected to uniaxial compressive strain. Nanovoids act as effective sources for dislocation emission. Dislocation shear loops nucleate at the surface of the voids and expand by the advance of the edge component. The evolution of dislocation configuration and densities were predicted by the molecular dynamics calculations and successfully compared to an analysis based on Ashby?s concept of geometrically-necessary dislocations. Resolved shear stress calculations were performed for all bcc slip systems and used to identify the operating Burgers vectors in the dislocation loops. The temperature excursion during plastic deformation was used to estimate the mobile dislocation density which is found to be less than 10% of the total dislocation density.
Fil: Ruestes, Carlos Javier. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. University of California; Estados Unidos
Fil: Bringa, Eduardo Marcial. Universitat Technische Darmstadt; Alemania. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina
Fil: Stukowski, A.. Universitat Technische Darmstadt; Alemania
Fil: Rodriguez Nieva, J.D.. Massachusetts Institute of Technology; Estados Unidos
Fil: Tang. Y.. University of California; Estados Unidos
Fil: Meyers, M. A.. University of California; Estados Unidos