PSI - Issue 66

Grzegorz Glodek et al. / Procedia Structural Integrity 66 (2024) 331–336 Author name / Structural Integrity Procedia 00 (2025) 000 – 000

336

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Lack of fusion defects

Sample edge

Critical defect

Figure 5 Crack surface of a dovetail geometry AM-Ti64 sample which failed outside contact with clearly visible lack of fusion defects.

4. Conclusion This work covers a part of the study focused on investigating fretting fatigue response of AM Ti64. The results of tests performed using dovetail geometry set-up show that both investigated materials are sensitive to the magnitude of the fatigue loading and show the inferior performance of AM Ti-64 caused by the presence of internal defects. Those defects, caused by the lack of fusion between subsequent layers during the LPBF process, resulted in failures outside the contact regions. These findings highlights the role of internal defects in AM processes on fretting fatigue response in critical applications such as turbine blades. Acknowledgements The authors gratefully acknowledge the support obtained through the CELSA/23/026#57631873 project. References [1] D.A. Hills, D. Nowell, J.J. O’Connor, On the mechanics of fretting fatigue, Wear 125 (1988) 129 – 146.. [2] C. Ruiz, P.H.B. Boddington, K.C. Chen, An investigation of fatigue and fretting in a dovetail joint, Exp. Mech. 24 (1984) 208 – 217. [3] P.J. Golden, T. Nicholas, The effect of angle on dovetail fretting experiments in Ti-6AI-4V, Fatigue Fract. Eng. Mater. Struct. 28 (2005) 1169 – 1175. https://doi.org/10.1111/j.1460-2695.2005.00956.x. [4] B.P. Conner, Contact Fatigue : Life Prediction and Palliatives, Mater. Sci. (2002). [5] A. Benziner, Siemens achieves breakthrough with 3D printed gas turbine blades, (2017). https://press.siemens.com/global/en/pressrelease/siemens-achieves-breakthrough-3d-printed-gas-turbine-blades. [6] M. Lavella, D. Botto, Fretting fatigue analysis of additively manufactured blade root made of intermetallic Ti-48Al-2Cr-2Nb alloy at high temperature, Materials (Basel). 11 (2018). https://doi.org/10.3390/ma11071052. [7] R. Talemi, A numerical study on effects of randomly distributed subsurface hydrogen pores on fretting fatigue behaviour of aluminium AlSi10Mg, Tribol. Int. 142 (2020) 105997. https://doi.org/10.1016/j.triboint.2019.105997. [8] ASTM B265, Standard Specification for Titanium and Titanium Alloy Strip , Sheet , and Plate 1, ASTM Int. (2009) 1 – 10. [9] O. Vingsbo, S. Söderberg, On Fretting Maps, Wear 126 (1988) 131 – 147. [10] S.L. Sunde, B. Haugen, F. Berto, Experimental and numerical fretting fatigue using a new test fixture, Int. J. Fatigue 143 (2021). [11] G. Glodek, R. Talemi, An applied approach for estimating fretting fatigue lifetime of dovetail joints using coupon scale test data, Theor. Appl. Fract. Mech. 121 (2022) 103455. https://doi.org/10.1016/J.TAFMEC.2022.103455. [12] J.W. Pegues, S. Shao, N. Shamsaei, N. Sanaei, A. Fatemi, D.H. Warner, P. Li, N. Phan, Fatigue of additive manufactured Ti-6Al-4V, Part I: The effects of powder feedstock, manufacturing, and post-process conditions on the resulting microstructure and defects, Int. J. Fatigue 132 (2020). https://doi.org/10.1016/j.ijfatigue.2019.105358.