**5. Conclusions**

In this work, influence of Si content, solidification rate, and pre-weld heat treatment on as-cast microstructure, weldability, and hot cracking susceptibility of alloy 718 investment castings were investigated. The following conclusions can be drawn about the impact of these factors and the selection of the different weldability tests which have been employed:


**Author Contributions:** P.Á.: Investigation in Varestraint, hot ductility, and bead-on-plate tests; methodology; formal analysis; and writing—original draft preparation. L.V.: Investigation in Varestraint, hot ductility, and bead-on-plate tests; methodology; data curation; and visualisation. A.C.: Investigation in Varestraint, hot ductility, and bead-on-plate tests; microstructural investigation; and visualisation. N.R.: Methodology, formal analysis, Varestraint investigation, and data curation. P.P.R.: Conceptualisation, methodology, investigation in investment casting, and writing—review. A.N.: Methodology, formal analysis, thermodynamic simulation, microstructural investigation, data curation, and writing—original draft preparation. A.M.: Methodology, formal analysis, microstructural investigation, and data curation. F.S.: Conceptualisation, methodology, supervision, writing—review and editing, project administration, and funding acquisition. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was performed under the framework of HiperTURB project, which was funded by Clean Sky 2 Joint Undertaking under the European Union's Horizon 2020 research and innovation program, grant agreement no. 755561.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Data available on request due to restrictions. The data presented in this study are available on request from the corresponding author. The data are not publicly available due to some IPR and confidentiality issues.

**Acknowledgments:** Bengt Pettersson and Vikström Fredrik from GKN Aerospace company in Trollhättan (Sweden) are gratefully acknowledged for their technical support and fruitful discussions. Additionally, the authors would like to thank the support received from Kejll Hurtig and Joel Andersson (Department of Engineering Science at West University) in carrying out hot ductility tests.

**Conflicts of Interest:** The authors declare no conflict of interest.
