Fatigue-induced phase formation and its deformation behavior in a cobalt-based superalloy (prop. 2002-090)
- ORNL
- University of Tennessee, Knoxville (UTK)
- Los Alamos National Laboratory (LANL)
- Queen's University, Ontario, Canada
- Oak Ridge Associated Universities (ORAU)
- Haynes International, Inc.
The low-cycle fatigue behavior of a cobalt-based superalloy was studied in situ using neutron-diffraction experiments. The alloy exhibited stress-induced formation of a hexagonal-close-packed (hcp) phase within its parent face-centered-cubic (fcc) phase at ambient temperature under strain-controlled fatigue conditions with a total strain range, {Delta}{var_epsilon} = 2.5%. The (101) hcp peak was first observed during the 12th fatigue cycle under the given conditions following a period during which no hcp phase was detected. Subsequently, the intensity of the hcp peaks increased as fatigue progressed. Furthermore, within a single fatigue cycle, the intensity of the (101) hcp peak decreased during the compression half-cycle and increased again when the specimen was subjected to a subsequent tensile strain. The result suggests that the fcc to hcp transformation is partially reversible within one fatigue cycle.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Temperature Materials Lab. (HTML)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 989515
- Journal Information:
- Powder Diffraction, Vol. 20, Issue 2; ISSN 0885-7156
- Country of Publication:
- United States
- Language:
- English
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