Inhomogeneity and size of Microstructure - A new paradigm in understanding deformation mechanism of nanocrystalline metals

Jagannathan Rajagopalan, Jong Han, Taher Saif

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We present experimental evidence showing that plastically deformed polycrystalline free standing thin metal films with average grain size of 50-65 nm recover a large fraction of plastic strain under macroscopically stress-free condition. We hypothesize, inhomogeneities in the microstructure (grain size and orientation variations) create non uniform local stress fields during loading as relatively larger or favorably oriented grain deform plastically while smaller or unfavorably oriented grains accommodate the strain elastically. Upon unloading, the elastically deformed grains, in order to reduce their strain energy, induce reverse plasticity in the larger grains leading to time dependent strain recovery in these films.

Original languageEnglish (US)
Title of host publicationPlasticity, Failure and Fatigue in Structural Materials-from Macro to Nano
Subtitle of host publicationProceedings of the Hael Mughrabi Honorary Symposium - Held during TMS 2008 Annual Meeting and Exhibition
Pages201-206
Number of pages6
StatePublished - Sep 18 2008
Externally publishedYes
EventPlasticity, Failure and Fatigue in Structural Materials-from Macro to Nano: Hael Mughrabi Honorary Symposium - Held during TMS 2008 Annual Meeting and Exhibition - New Orleans, LA, United States
Duration: Mar 9 2008Mar 13 2008

Publication series

NameTMS Annual Meeting

Other

OtherPlasticity, Failure and Fatigue in Structural Materials-from Macro to Nano: Hael Mughrabi Honorary Symposium - Held during TMS 2008 Annual Meeting and Exhibition
CountryUnited States
CityNew Orleans, LA
Period3/9/083/13/08

Keywords

  • Nanocrystalline microstructure
  • Plastic deformation
  • Strain recovery
  • Thin films

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys

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  • Cite this

    Rajagopalan, J., Han, J., & Saif, T. (2008). Inhomogeneity and size of Microstructure - A new paradigm in understanding deformation mechanism of nanocrystalline metals. In Plasticity, Failure and Fatigue in Structural Materials-from Macro to Nano: Proceedings of the Hael Mughrabi Honorary Symposium - Held during TMS 2008 Annual Meeting and Exhibition (pp. 201-206). (TMS Annual Meeting).