A constitutive model of nanocrystalline metals based on competing grain boundary and grain interior deformation mechanisms

Gürses E., El Sayed T.

MATERIALS LETTERS, cilt.65, ss.3391-3395, 2011 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 65
  • Basım Tarihi: 2011
  • Doi Numarası: 10.1016/j.matlet.2011.07.039
  • Dergi Adı: MATERIALS LETTERS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.3391-3395
  • Anahtar Kelimeler: Nanocrystalline materials, Diffusion, Grain boundaries, Simulation and modeling, SIZE DISTRIBUTION, FCC METALS, PRESSURE, STRENGTH, BEHAVIOR, DIFFUSION, DEPENDENCE, ASYMMETRY, ALLOY
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

In this work, a viscoplastic constitutive model for nanocrystalline metals is presented. The model is based on competing grain boundary and grain interior deformation mechanisms. In particular, inelastic deformations caused by grain boundary diffusion, grain boundary sliding and dislocation activities are considered. Effects of pressure on the grain boundary diffusion and sliding mechanisms are taken into account. Furthermore, the influence of grain size distribution on macroscopic response is studied. The model is shown to capture the fundamental mechanical characteristics of nanocrystalline metals. These include grain size dependence of the strength, i.e., both the traditional and the inverse Hall-Fetch effects, the tension-compression asymmetry and the enhanced rate sensitivity. (C) 2011 Elsevier B.V. All rights reserved.