Grain boundary versus transgranular ductile failure

T. Pardoen, D. Dumont, A. Deschamps, Y. Brechet

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106 Citations (Scopus)

Abstract

The competition between intergranular and intragranular fracture is investigated using a bilayer damage model, which incorporates the relevant microstructural features of aluminium alloys with precipitate free zones (PFZ) nearby the grain boundary. One layer represents the grain behaviour: due to precipitation, it presents a high yield stress and low hardening exponent. The other layer represents the PFZ which has the behaviour of a solid solution: it is much softer but with a much higher strain hardening capacity. In both layers, void growth and coalescence is modelled using an enhanced Gurson-type model incorporating the effects of the void aspect ratio and of the relative void spacing. The effects on the ductility (i) of the flow properties of each zone, (ii) of the relative thickness of the PFZ, and (iii) of the particles spacing and volume fraction in the PFZ are elucidated. Comparisons are made with experimental data. Based on the previous analysis, qualitative understanding of trends in the fracture toughness of aluminium alloys can be gained in order to provide a link with the thermal treatment process.

Original languageEnglish
Pages (from-to)637-665
Number of pages29
JournalJournal of the Mechanics and Physics of Solids
Volume51
Issue number4
DOIs
Publication statusPublished - Apr 2003
Externally publishedYes

Keywords

  • A. Fracture mechanisms
  • A. Grain boundaries
  • A. Voids and inclusions
  • B. Constitutive behaviour
  • B. Elastic-plastic porous material

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