ISSN:
1460-2695
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract— The high temperature low cycle fatigue behaviour of a directionally solidified Ni-base superalloy hardened by about 65% volume fraction of γ'-precipitates was investigated in order to determine the fatigue life parameters for longitudinal (L) and longitudinal transverse (LT) grain orientations. The fatigue resistance was compared with that of two oxide dispersion strengthened (ODS) Ni-base superalloys with a similar elongated grain structure.The fatigue life of the alloy can be adequately predicted by Basquin and Coffin-Manson empirical relationships and the fatigue ductility parameters in these relationships show a similar trend with the tensile ductility properties.The studied alloy exhibits a fairly stable cyclic stress response, with only a slight stress softening. Fatigue crack initiation occurs mainly at shrinkage pores on the surface or sub-surface of the specimens. The crack growth direction is predominantly perpendicular to the applied load. The fracture mode in the LT-direction is transgranular and fatigue life is shorter by a factor of about six compared to the L-direction. The fatigue life of the alloy is longer than that of the ODS Ni-base superalloys with which it is compared.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1460-2695.1996.tb01031.x
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