Creep-induced local lattice parameter changes in a monocrystalline nickel-base superalloy

H. Mughrabi, H. Biermann, T. Ungar

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The γ-γ lattice mismatch of specimens of the monocrystalline nickel-base superalloy SRR 99 has been measured by a high-resolution X-ray diffraction technique for the undeformed state and after high-tem-perature creep deformation. During creep deformation beyond the minimum creep rate (total strain =0.5%), the lattice mismatches, measured in and perpendicular to the [001] stress axis, respectively, un-dergo changes in opposite directions. This reflects the buildup of a complex deformation-induced triaxial state of internal stress in the phases y and γ. The overall resolved shear stresses that act in γ and y due to the combined action of the external and internal stresses are estimated, and the conditions under which cutting of the γ phase by dislocations should occur are discussed.

Original languageEnglish
Pages (from-to)557-564
Number of pages8
JournalJournal of Materials Engineering and Performance
Volume2
Issue number4
DOIs
Publication statusPublished - Aug 1 1993

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Keywords

  • X-ray diffraction
  • high-temperature creep
  • internal stress
  • lattice mismatch
  • nickel-base superalloy
  • residual stress

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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