Analysis of deformation substructures in a notched LCF sample under dwell condition in a Ni-based superalloy

G. B. Viswanathan, Ken Bain, Dan Huber, S. Jha, S. Sam, J. Tiley, Christopher Woodward, H. L. Fraser

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

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Detailed transmission electron microscopy (TEM) studies were conducted on low cycle fatigue (LCF) sample of René 104 alloy samples tested under dwell conditions to analyze the deformation substructures. Specifically, the focus was to investigate the effect of crack length, in other words, stress intensity factor range AK, on the deformation substructures. Thin foils were prepared by focused ion beam method (FIB) from two specific grains along the crack path at varying distances representing varying AK values. The TEM analysis indicated that the character of deformation substructures significantly differed in these two grains. It is therefore speculated that local stress conditions and the grain orientations played a key role in the damage accumulation and subsequent substructure evolution. The regions below the fracture surface were also investigated. Detailed scanning electron microscopy (SEM) investigations of the grains immediately below the fracture surface revealed extensive nucrostructure degradation and potential hot spots for crack nucleation.

Original languageEnglish
Title of host publicationSuperalloys 2012
Subtitle of host publicationProceedings of the 12th International Symposium on Superalloys, held, September 9-13, 2012, at Seven Springs Mountain Resort, Seven Springs, PA
EditorsEric S. Huron, Roger C. Reed, Mark C. Hardy, Michael J. Mills, Rick E. Montero, Pedro D. Portella, Jack Telesman
Place of PublicationHoboken, New Jersey
PublisherJohn Wiley & Sons
Number of pages7
ISBN (Electronic)9781118516430
ISBN (Print)9780470943205
Publication statusPublished - 2012
Externally publishedYes
EventInternational Symposium on Superalloys 2012 - Seven Springs, United States of America
Duration: 9 Sep 201213 Sep 2012
Conference number: 12th


ConferenceInternational Symposium on Superalloys 2012
Abbreviated titleSuperalloys 2012
Country/TerritoryUnited States of America
CitySeven Springs


  • Deformation
  • Dislocations
  • Dwell-fatigue
  • Low cycle fatigue
  • Superalloy
  • Transmission electron microscopy

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