## 4 Conclusions  
The following conclusions can be drawn from the analyses carried out on the hybrid Inconel 718 coupon tested using SPT.  
* The SPT method is sensitive enough and useful to characterize mechanical properties at the different studied conditions: 100% wrought, 100% DED-LB, 50% wrought + 50% DED-LB, and 80% wrought + 20% DED-LB.  
Figure 13: Comparison between different correlations in SPT for the characterization of Inconel 718. (**a**) Maximum load, \(R_{m}\). (**b**) Yield strength, \(R_{p0.2}\).  
* The best mechanical properties are obtained for the 100% wrought sample, while the lowest are for the 100% DED-LB sample.
* The results obtained for samples that include a joining area between the wrought base and DED-LB-deposited material show that: \(\odot\) The SPT values of the hybrid samples are below, but not far off, the weighted value of the SPT results of the pure samples: \(-4.5\%\) for \(R_{m}\) and \(-17\%\) for \(R_{p0.2}\). \(\odot\) Thus, the joining area is not the weak zone of the part, so it can be concluded that the overlay of Inconel 718 via DED-LB adhered correctly to the wrought Inconel 718 base.
* The comparison between the different correlations for the estimation of the mechanical properties show that, even not including the exact material in the correlation, the results can be adequately estimated if the correlation considers materials with a wide range of mechanical properties.
* The use of DED-LB for repairing Inconel 718 parts should be analyzed carefully if post-weld heat treatments are not applicable. The evolution of embrittling Laves phases is a source of decreases in the mechanical properties if the DED-LB is performed under conditions of high heat concentrations, as is the case of this work.
* Regarding the extension of the proposed SPT methodology for the joint area assessment, the approach of this work is applicable for a DED-LB overlay thickness as thin as 1.5 mm while meeting standard testing method requirements. This is achieved by employing the reduced size specimen (\(\O 3\) mm) from the EN 10371-2021 [34] SPT standard and accounting both for the 20/80 positioning and the machining clearance for specimen extraction. This opens a field of research on joints in thin DED-LB-manufactured parts that did not have an ad hoc technique available yet.  
Conceptualization: G.A.; methodology: G.A.; investigation: I.M. and J.I.A.; writing--original draft preparation: J.I.A. and A.I.F.-C.; writing--review and editing: I.M., J.I.A., A.I.F.-C., G.A. and C.A.; supervision: C.A.; project administration: A.I.F.-C.; and funding acquisition: G.A. All authors have read and agreed to the published version of the manuscript.  
This research was partially funded by the ELKARTEK 2023 program from the Basque Government's Department of Economic Development, Sustainability, and Environment, project ReIMAGIN under grant number KK-2023/00096. This work was also partially funded by the Basque Government under grant number 004-B2/2021, corresponding to the BIKAINTEK Program for PhD students. Finally, this work was also partially funded by the Department of Research and Universities of the Basque Government under grant number IT1542-22.  
Data available upon request to the authors.  
The authors would like to thank [PERSON] for his contribution to the setup of the DED-LB process and [PERSON] for her contribution of cross-sections of fracture SPT samples' analysis.  
The authors declare no conflicts of interest.