Determination of the effects of the parameters on process and product for directed energy deposition metal additive manufacturing

In order to eliminate the manufacturability constraints, the additive manufacturing process is becoming widespread day by day. Additive manufacturing is used in many different fields such as automotive, defence & aerospace, medicine, energy and equipment. The Direct Energy Deposition (DED) process is one of the additive manufacturing sub-branches. In the DED production method, the sprayed powder or the fed wire from the nozzle on the part is melted with the laser and stacked on the material layer by layer. With the DED process, it is possible to manufacture products with different topological properties, repair parts such as molds in large structures, and add new functions to existing parts with the same or different materials. In this study, the Taguchi table was created by using 316L-Si powder material for laser power (1300-1400-1500 W), laser scanning speed (8-9-10 mm/s) and powder feed amount (5.59-6.52-7.45 g/min) parameters. The parameters in this table were analyzed with the FLOW-3D® software for single-layer scanning, their production was made with experimental studies, and the mathematical model was created with the results obtained from the experimental studies. As a result of virtual analysis studies and experimental studies, width, height, depth, and dilution ratios for single-layer scanning were measured and compared with each other. In the results obtained from the virtual analysis studies, the temperature distributions in the scans were compared depending on the parameter changes. The cooling rates between two points were evaluated. The effects of specific energy density (SED) and powder feed density (PFD) on scanning height, width and depth were investigated. The parameter that has the most important effect on the scanning height is the powder feed rate and the laser power in the scanning width. Both laser power and powder feed rate are critical for scanning depth. The highest temperature values are seen at high laser power, low scanning speed and high powder feed amount.