Optimization of process parameters for DED of IN718 superalloys via Single scan track and single-layer analysis

Additive Manufacturing (AM) is one of the most interesting class of technologies in the industrial environment that has been considered a fundamental part of Industry 4.0. There are several types of AM, but in this thesis, we will focus on Directed Energy Deposition (DED), which is a material feed metal AM process and has several promising applications in the Aerospace sector. The goal of this thesis was to analyse different kinds of Inconel 718 samples produced via the DED process in order to define the optimum set of process parameters to produce or repair the defect-free IN718 parts. The analysed samples are of three different types: 36 “Single Scan Tracks” (SSTs), 12 “Single Layers” (SLs), and 2 “Cubes”. The specimens have been realized using several laser powers, feed rate levels, and hatching distances. Thereafter, the interface of the substrate/deposited layer is analysed carefully to explore the potential of the DED process in the repair of high-value components. The analysed samples are evaluated in terms of their Defectology as well as their Morphological and Microstructural aspect. All in all, it is concluded that optimization of process parameters starting from SSTs analysis is a very cost and time-effective approach.