Low-cycle fatigue behavior of NIMONIC PE16 at room temperature

Abstract

The fatigue behavior of NIMONIC PE16 has been investigated at room temperature as a function of γ′ particle size (from 10 to 30 nm) and total strain amplitude (0.44 to 2.60 pct). All specimens initially harden and then soften on further deformation. The degrees of hardening and softening show a marked variation with γ′ particle size and strain amplitude. Cyclic stress-strain and Coffin-Manson plots show a bilinear behavior with a change of slope at Δεp/2, the plastic strain amplitude, of about 0.3 pct. These results are interpreted in terms of microstructural observations, namely, the number of slip systems activated and mutual interaction of dislocations on these systems, as well as their interaction with γ′ particles. © 1991 The Minerals, Metals and Materials Society, and ASM International.