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Nanoscale contact plasticity of crystalline metal / T. Tsuru in Acta materialia, Vol. 58 N° 8 (Mai 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 8 (Mai 2010) . - pp. 3096–3102 Titre : Nanoscale contact plasticity of crystalline metal : Experiment and analytical investigation via atomistic and discrete dislocation models Type de document : texte imprimé Auteurs : T. Tsuru, Auteur ; Y. Shibutani, Auteur ; Y. Kaji, Auteur Année de publication : 2011 Article en page(s) : pp. 3096–3102 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Nanoplasticity  Molecular  statics  Discrete  dislocation  mechanics  Boundary  element  method  Nanoindentation Résumé : Nanoscale incipient plastic deformation in crystalline metals occurs as the result of the collective motion of dislocations. It is known as “nanoplasticity” and is recognized as the elementary process of the macroscopic deformation. Abrupt increases in indent displacements called displacement bursts were observed in recent nanoindentation experiments; that is, the specific behavior for nanoplasticity. In the present study, experimental tests are first conducted to educe the unique nature of the nanoscale deformation. Subsequently, large-scale atomistic simulations are performed to predict the incipient plastic deformation and a new discrete dislocation model combined with the boundary element analysis is constructed to capture the collective motion of the dislocations. Our results suggest that the incipient plastic deformation requires much higher critical shear stress than the theoretical shear strength due to high compressive stress distribution beneath the indenter, and that the displacement burst is induced by surface rearrangement corresponding to hundreds of dislocation dipoles. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410000789 [article] Nanoscale contact plasticity of crystalline metal : Experiment and analytical investigation via atomistic and discrete dislocation models [texte imprimé] / T. Tsuru, Auteur ; Y. Shibutani, Auteur ; Y. Kaji, Auteur . - 2011 . - pp. 3096–3102. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 8 (Mai 2010) . - pp. 3096–3102 Mots-clés : Nanoplasticity  Molecular  statics  Discrete  dislocation  mechanics  Boundary  element  method  Nanoindentation Résumé : Nanoscale incipient plastic deformation in crystalline metals occurs as the result of the collective motion of dislocations. It is known as “nanoplasticity” and is recognized as the elementary process of the macroscopic deformation. Abrupt increases in indent displacements called displacement bursts were observed in recent nanoindentation experiments; that is, the specific behavior for nanoplasticity. In the present study, experimental tests are first conducted to educe the unique nature of the nanoscale deformation. Subsequently, large-scale atomistic simulations are performed to predict the incipient plastic deformation and a new discrete dislocation model combined with the boundary element analysis is constructed to capture the collective motion of the dislocations. Our results suggest that the incipient plastic deformation requires much higher critical shear stress than the theoretical shear strength due to high compressive stress distribution beneath the indenter, and that the displacement burst is induced by surface rearrangement corresponding to hundreds of dislocation dipoles. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410000789