PSI - Issue 51

Juraj Belan et al. / Procedia Structural Integrity 51 (2023) 109–114 J. Belan et al. / Structural Integrity Procedia 00 (2022) 000–000

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4. Conclusions In conclusion, it can be summarized that the method of loading during the fatigue, represented by the cycle asymmetry parameter R, does not significantly influence how the fatigue cracks initiate. However, it significantly affects the initiation time and thus also the fatigue life of the alloy itself, because approximately 75-80% of the fatigue life of the alloy is represented by the fatigue crack initiation phase. In three-point bending, crack initiation occurred at higher load amplitudes earlier than compared to push-pull loading. In all cases, with a decreasing value of the load amplitude, the number of initiation sites also changed and decreased. The effect of frequency on the mechanism of fatigue crack initiation was negligible for the number of cycles over 10 5 because, at higher numbers of cycles to fracture, the stress component represented by the load amplitude is more likely to be responsible for the initiation. Acknowledgements The authors acknowledge the KEGA project 004ŽU-4/2023 for the financial support of this work. References Alexandre, F., Deyber, S., Pineau, A., 2004. Modelling the optimum grain size on the low cycle fatigue life of a Ni based superalloy in the presence of two possible crack initiation sites. Scripta Materialia 50, 25-30. Almaraz, G. M. D., Tapia, M. G., Dominguez, A., 2020. Ultrasonic Fatigue Tests on the Inconel Alloy 718. Procedia Structural Integrity 26, 20 27. Almaraz, G. M. D., Tapia, M. G., Tello, I. F. Z., 2022. Ultrasonic fatigue endurance of Inconel 718 after the heat treatments: solution annealing and double aging. Procedia Structural Integrity 39, 281-289. Belan, J., Hurtalová, L., Vaško, A., Tillová, E., 2004. Metallography Evaluation of IN 718 after Applied Heat Treatment. Manufacturing Technology 14, 262-267. Belan, J., 2016. GCP and TCP Phases Presented in Nickel-base Superalloys. Materials Today: Proceedings 3, 936-941. Belan, J., Kuchariková, L., Tillová, E., Matvija, M., Uhríčik, M., 2021. The Hardness Evolution of Cast and the High-Cycle Fatigue Life Change of Wrought Ni-Base Superalloys after Additional Heat Treatment. Materials, vol. 14. Buque, C., 2001. Persistent slip bands in cyclically deformed nickel polycrystals. International Journal of Fatigue, vol. 23, iss. 6, pp. 459-466. Davis, J. R. (Eds.), 2000. Nickel, Cobalt, and Their Alloys. ASM Specialty Hndbook, ASM International, Materials Park, OH 44073-0002, ISBN 13: 987-087170-685-0, p. 442. Geddes, B., Leon, H., Huang, X., 2010. Superalloys: Alloying and Performance, ASM International, Materials Park, OH 44073-0002, ISBN-13: 978-1615030408, p. 176. Ghorbanpour, S., Saswat, S., Kaustubh, D., Borisov, E., Riemslag, T., Reinton, E., Bertolo, V., Jiang, Q., Popovich, A., Shamshurin, A., Knezevic, M., Popovich, V., 2021. Effect of microstructure induced anisotropy on fatigue behaviour of functionally graded Inconel 718 fabricated by additive manufacturing. Materials Characterization 179, 1-18. Huang, J. F., Wang, Z. L., Yang, E. F. et al., 2017. Molecular dynamics simulation of persistent slip bands formation in nickel-base superalloys. International Journal of Automation and Computing 14, 68–79. Chen, C., Wang, Q., Dong, C. et al., 2020. Composition rules of Ni-base single crystal superalloys and its influence on creep properties via a cluster formula approach. Scientific Reports 10, 1-13. Liu, D., Pons, D. J., 2018. Crack Propagation Mechanisms for Creep Fatigue: A Consolidated Explanation of Fundamental Behaviours from Initiation to Failure. Metals 8, 1-32. Man, J., Obrtlík, K., Polák, J., 2009. Extrusions and intrusions in fatigued metals. Part 1. State of the art and history. Philosophical Magazine 89, 1295–1336. Ono, Y., Yuri, T., Sumiyoshi, H., Takeuchi, E., Matsuoka, S., Ogata, T., 2004. High-Cycle Fatigue Properties at Cryogenic Temperatures in INCONEL 718 Nickel-based Superalloy. Materials Transactions 45, 342-345. Pieraggi, B., Uginet, J. F., 1994. Fatigue and creep properties in relation with alloy 718 microstructure, Superalloys 718,625,706 and Various Derivatives, Edited by E.A. Loria, The Minerals, Metals & Materials Society, pp. 535- 544. Rafiei, M., Mirzadeh, H., Malekan, M., 2020. Delta processing effects on the creep behavior of a typical Nb-bearing nickel-based superalloy. Vacuum 184, 1-4. Zhang, Y. Y., Duan, Z., Shi, H. J., 2013. Comparison of the very high cycle fatigue behaviours of INCONEL 718 with different loading frequencies. Science China 56, 617-623.