The Effect of Temperature and Phase Shift on the Thermomechanical Fatigue of Nickel-Based Superalloy

0558952 - ÚFM 2023 RIV CH eng J - Journal Article
Šulák, Ivo - Hrbáček, Karel - Obrtlík, Karel
The Effect of Temperature and Phase Shift on the Thermomechanical Fatigue of Nickel-Based Superalloy.
Metals. Roč. 12, č. 6 (2022), č. článku 993. E-ISSN 2075-4701
Institutional support: RVO:68081723
Keywords : nickel-based superalloy * high-temperature fatigue * in-phase * out-of-phase * cyclic stress-strain curves * fatigue life curves
OECD category: Audio engineering, reliability analysis
Impact factor: 2.9, year: 2022
Method of publishing: Open access
https://www.mdpi.com/2075-4701/12/6/993

In this paper, the minimum temperature and phase shift effects on the thermo-mechanical fatigue (TMF) behavior of Inconel 713LC are investigated. TMF tests were performed under 0 degrees (in-phase-IP) and +180 degrees (out-of-phase-OP) phase shifts between mechanical strain and temperature. Cylindrical specimens were cycled at constant mechanical strain amplitude with a strain ratio of R-epsilon =1. Tests were performed with temperature ranges of 300-900 degrees C and 500-900 degrees C. The heating and cooling rate was 5 degrees C/s. Fatigue hardening/softening curves and fatigue life data were assessed. Results show that out-of-phase loading was less damaging than in-phase loading. Scanning electron microscopy (SEM) examination of metallographic sections indicated that the life-reducing damage mechanism was intergranular cavitation under in-phase loading. Transmission electron microscopy (TEM) revealed honeycomb structures for IP loading. The plastic strain localization into persistent slip bands was typical for OP loading. For out-of-phase loading, fatigue damage appeared to be dominant. The increase in the temperature range led to a significant decrease in fatigue life. The reduction of fatigue life was far more pronounced for out-of-phase loading. This can be ascribed to the accelerated crack propagation at high tensile stress under out-of-phase loading as well as the amount of accommodated plastic strain deformation. Based on the SEM scrutiny of metallographic sections and TEM observations of dislocation arrangement, the prevailing damage mechanisms were documented and the lifetime behavior was accordingly discussed.
Permanent Link: https://hdl.handle.net/11104/0332575