**4. Conclusions**

The damage mechanism under thermal cycling is complicated and not very well understood. Creep and fatigue failure mechanisms related to several factors of dwell time and stress level are detected to have a major degradation effect on fatigue life. It was found that increasing the dwell time and/or the stress magnitude will reduce life. Moreover, at certain stress magnitudes, life is substantially decreased when increasing dwell time. The relation between life and stress amplitude is explored according to the life– stress equation. Results found to fit a power equation for all cases, and empirical models to predict the reliability as a function of dwell time and stress level, were generated accordingly. Furthermore, increasing the dwell time and/or stress level leads to more damage per cycle, which means more dissipated work per cycle and plastic strain. Degradation models were generated as a function of plastic strain and inelastic work per cycle based on Coffin– Manson and Morrow Energy models, respectively.

**Author Contributions:** Conceptualization, S.H. and M.A.; methodology, R.A.A., S.H. and M.A.; validation, R.A.A. and M.A.; formal analysis, M.A.; investigation, M.A. and M.T.; resources, M.A.; data curation, S.H. and M.A.; writing—original draft preparation, S.H. and M.A.; writing—review and editing, M.T. and S.H.; visualization, S.H.; supervision, S.H.; project administration, R.A.A., M.T. and S.H. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable. **Data Availability Statement:** The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

**Conflicts of Interest:** The authors declare no conflict of interest.
