Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
A study on the applicability of GTAW as an energy source for DED and PBF processes in Additive Manufacturing
Submission Author:
Alcindo Moreira , SP
Co-Authors:
Alcindo Moreira, Reginaldo Coelho, Fábio Mariani
Presenter: Alcindo Moreira
doi://10.26678/ABCM.COBEM2023.COB2023-0138
Abstract
Additive manufacturing (AM) process are currently gaining visibility due to factors such as the possibility of producing complex parts, less material removal to achieve final dimensions and shapes, less production time, less generation of waste resulting from material removal manufacturing. However, the high cost of the devices used for the production of parts by AM, the dimensional limitation of the parts that these devices are capable of producing and the low energy efficiency of some of the current processes for the production of metal parts are still some of the obstacles to be won. The present work makes a study on the applicability of GTAW (Gas Tungsten Arc Welding) welding processes as a power supply combined with the use of metallic powder for the production of parts by AM. For that, 4 (four) experimental devices were developed, 2 (two) based on the PBF (Powder Bed Fusion) process and 2 (two) based on the DED (Directed Energy Deposition) process. In all these prototypes, automatic movement of the welding torch was used in the direction of displacement in order to have a uniform speed of fusion of the metallic powder. The use of metallic powder was preferred due to the availability of commercial metallic alloys and the possibility of generating a metallic deposit as a product of the composition of different proportions of these materials. In this study metallic powder of AISI H-13 steel was used on an ABNT 1020 steel base. At first, superficial aspects of the single bead deposited metal were analyzed, in order, from these observations, to carry out the deposition of overlapping beads (wall), side by side beads (layers) and, finally, the stacking of various layers in order to generate a three-dimensional (3D) object. The results obtained, by that time, indicated that the use of the GTAW welding process based on the DED process allows the production of parts by AM presented lower incidence of surface defects, better dimensional uniformity, better geometric repeatability, and, thus, greater predictability for planning the torch displacement trajectory when compared to that based on the PBF process. Therefore, the potential for developing a hybrid equipment for the production of parts by AM was observed, where the use of the GTAW welding process with the addition of metallic powder must be followed by subtractive processes in the same place.
Keywords
PBF, Directed Energy Deposition, GTAW process, metal powders
