Study on factors for pores and cladding shape in the deposition processes of Inconel 625 by the directed energy deposition (DED) method

Additive manufacturing has been utilized recently for prototyping and mass production of parts especially in the aerospace and medical industries. Most of the parts are processed by the powder bed fusion (PBF) method. On the other hand, the directed energy deposition (DED) method is attractive due to the high deposition speed. However, various parameters must be set for deposition processes and how these parameter settings affect the quality of products in terms of pores and machine properties have not been clarified. This paper studies factors contributing to pore generation in the deposition processes of Inconel 625 by the DED method. First, tests for deposition processes in single layer and multiple layers were conducted under various depositing conditions by changing the laser output and the amount of powder. The test results have clarified depositing conditions where less pores are generated, differences in hardness by deposited position, and the factors for those differences.