VIABILITY ANALISYS FOR LASER DIRECTED ENERGY DEPOSITION (L-DED) OF POWDER MATERIAL15CDV6

The aim of the present research work is the characterization of the 15CDV6 powder material for Laser Directed Energy Deposition (L DED) processes. The novelty of the work lays on the fact that this aeronautical steel has never been employed before in powder L DED process. Therefore, the mentioned steel powder was atomized specifically for the present work and the chemical composition and shape of the particles was measured to ensure the quality of the material. Afterwards, the suitability of the 15CDV6 steel for the L-DED process was studied and the employed methodology consisted of 3 sequential steps: single bead tests, overlapping beads deposition and thin wall construction. The results of each sequence are used as the basis for the following ones. In addition to the determination of the main process parameters, the influence of the deposition strategy on the process efficiency is analyzed and a correlation between the microstructure resulting from the thermal process and the hardness HV0.3 values was obtained. To finish the characterization of the process, a demonstrator part was fabricated using the optimum parameters defined during the tests. Based on the obtained results, the viability of employing 15CDV6 steel in the L-DED process is ensured. Also, it is concluded that if a sufficient cooling rate is ensured, Acicular Ferrite microstructure is obtained, which provides good mechanical properties to the L-DED manufactured parts. Nevertheless, the thermal evolution of the process needs to be controlled in order to avoid heat accumulation and cooling stops are to be applied when required.
Keywords: 15CDV6, powder, L-DED, characterization, atomization.