Development of an Innovative directed energy deposition process based on gas tungsten arc welding and powder metal

Directed Energy Deposition (DED) is one of the most promising processes to build and repair high value components in different areas. This work aims to develop, built and test an innovative DED process using Gas Tungsten Arc Welding (GTAW) as a heating source and powder metal as raw material. The relevance of this research is supported by the high costs, lower energy efficiency and dimensional limitations offered by some Additive Manufacturing (AM) processes that use electron beam or laser like energy source. Samples in single, side-by-side, stacking and multi layers were deposited upon AISI 1020 steel substrate and using AISI H-13 steel powder as raw material. Shape, dimensions, defects, dilution and hardness were analyzed. The results showed that is possible the use of GTAW arc for melting metallic powder in DED process, however, a precise control of metallic powder feeding is necessary. Dilution and thermal cycles, depending on the intensity, can influence the microstructure and hardness of the deposit.