Summary: | This study aims to optimize the process parameters for PBF-LB of Inconel 718 using the surface texture and density of the as-built specimen to fabricate high-quality products. In order to achieve this aim, the melting and solidification phenomena of the melt pool were examined using a high-speed camera, and the process map of laser power and scan speed was constructed by evaluating the surface texture and density of the as-built specimen to optimize the process parameters. In addition, the mechanical properties of the as-built specimens fabricated at the optimum process parameter derived from the process map were examined. Consequently, it was found that the optimum process parameter should be determined by consideration of the melting and solidification phenomena because the phenomena such as spattering and instability of the melt pool change with the process parameters. It was also found that the morphology of the track is affected by the spot size of the laser beam. It was revealed that the similarity of the process maps evaluated by surface texture and density of the specimens results in the correlation between the surface texture and the density. The optimum laser power and scan speed can be determined using the process maps evaluated by the surface texture and density of the specimens. The as-built specimen fabricated at the optimum process parameter showed anisotropic tensile behavior, and the tensile strength of the transverse specimen was higher than that of the longitudinal specimen. The tensile properties of the as-built specimen fabricated in this work were similar to those of the as-built specimen reported by the other works.
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