PSI - Issue 37

L.P. Borrego et al. / Procedia Structural Integrity 37 (2022) 330–335 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 3. Crack closure levels due to overloads application, R=0 OLR 2.

A representative example, can be observed in Figure 4 showing the FCGR fracture surface for R=0 with OLR=2 applied at ∆K=14 MPam 1/2 . The red arrows point to the overload mark, in this case a very short transient period during the overload effect can be observed (2.89 µm approximately) which is coincident with the FCGR behaviour observed and described previously for the applied overloads at R=0

OLR mark

Fig. 4. Fracture surface for R=0 with OLR=2 at ∆K =14 MPam 1/2 .

4. Conclusions In the current investigation, an experimental FCGR study using CT specimen made of Ti-6Al-4V produced by LPBF process submitted to HIP process, was performed for constant and variable loading. The main conclusions are listed as follows: Crack closure induced by plasticity for the stress ratio R=0 was observed for the Paris regime; The applied overloads for OLR=2 caused a FCGR rate retardation due to the increase of crack closure mechanism induced