Effects of anisotropy and slip geometry on fatigue fracture of Cu/sapphire bicrystals

Pedro Peralta, U. Ramamurty, S. Suresh, G. H. Campbell, W. E. King, T. E. Mitchell

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

Interfacial fatigue cracks were propagated in Cu/sapphire bicrystals with effect of anisotropy and slip geometry in the fracture process. Compact tension specimens with two different crystallographic crack growth directions were loaded to ΔKla ≃ 2 Mpa m1/2 with R*0. Interfacial cracks grew preferentially along <110>Cu and less favorably along <001>Cu. Large areas of the copper fracture surface were relatively featureless for crack growth along <110>Cu, whereas well defined striations could be observed for the second direction. A refined elastic analysis of the anisotropic near-tip fields for the interfacial crack revealed that the preferential crack growth direction had the highest energy release rate and mode I crack tip opening displacement. The second direction corresponded to a minimum mode II mix. Similar correlations were found in other Cu/sapphire bicrystal experiments described in the literature. Dislocation nucleation from the interfacial crack tip is also analyzed.

Original languageEnglish (US)
Pages (from-to)55-66
Number of pages12
JournalMaterials Science and Engineering A
Volume314
Issue number1-2
DOIs
StatePublished - Sep 15 2001

Keywords

  • Anisotropy
  • Compact tension
  • Cu/sapphire bicrystal
  • Interfacial crack

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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