PSI - Issue 53

Venanzio Giannella et al. / Procedia Structural Integrity 53 (2024) 172–177 Raffaele Sepe / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 5. Crack-growth rate for different building directions.

4. Conclusions This research aimed at assessing the fatigue crack propagation behavior of TiAl64V specimens made by EBM tested in laboratory conditions. The main objective was to quantify the impact of the building direction on the residual fatigue life. Tests were carried out using standard C(T) specimens by considering constant amplitude load with R = 0.1 and frequency sets to 10 Hz. Different measurement techniques were adopted and compared: the best solution resulted to be the back face strain measurement system that, using the strains monitored at the back face during the tests, allowed to derive the evolution of the crack length during the cycling in very good way. Commonly, many studies highlight that the building direction plays a significant role on the fracture behaviour of EBMed structures. However, this was not the case, since small variations were noticed among them. Nonetheless, specimens manufactured in-plane returned slightly longer fatigue lives than the others. References Alfieri, V., Giannella, V., Caiazzo, F., Sepe, R., 2022. Influence of position and building orientation on the static properties of LPBF specimens in 17 – 4 PH stainless steel. Forces Mech 8, 100108. Bellini, C., Borrelli, R., Di Cocco, V., Franchitti, S., Iacoviello, F., Sorrentino, L., 2021. Bending properties of titanium lattice structures produced by electron beam melting process. Fatigue and Fracture of Additively Manufactured Materials 44(7), 1961-1970. Bellini, C., Borrelli, R., Di Cocco, V., Franchitti, S., Iacoviello, F., Sorrentino, L., 2022. Titanium lattice structures manufactured by EBM process: Effect of skin material on bending characteristics. Engineering Fracture Mechanics 260, 1081800. Borrelli, R., Franchitti, S., Pirozzi, S., Carrino, L., Nele, L., Polini, W., et al., 2020. Ti-6Al-4V parts produced by electron beam melting: analysis of dimensional accuracy and surface roughness. J Adv Manuf Technol 19(1), 1-24. Califano, A., Bollino, F., Berto, F., Sepe, R., 2023. Experimental investigation of the fatigue crack growth behaviour in SLM additively manufactured 17-4 PH stainless steel specimens. Procedia Structural Integrity 48, 238-243. Citarella, R., Giannella, V., 2021. Additive Manufacturing in Industry. Applied Sciences 11, 840. De Luca, A., Lamanna, G., Caputo, F., Borrelli, R., Franchitti, S., Pirozzi, C., Sepe, R., 2021. Effects of the surface finish on t in specimens made by electron beam melting technology. Macromol Symp 396, 2000307. Facchini, L., Magalini, E., Robotti, P., Molinari, A., 2009. Microstructure and mechanical properties of Ti-6Al-4V produced by electron beam melting of pre-alloyed powders. Rapid Prototyp J 15(3), 171-178.