A comparative study on laser powder bed fusion of IN718 powders produced by gas atomization and plasma rotating electrode process

The effects of powder feedstocks prepared by different methods on the processibility of the powders and the performance of final components have largely been unexplored in metal additive manufacturing (MAM). In this paper, we conducted a comparative study on the laser powder bed fusion (LPBF) process of Inconel 718 (IN718) powders produced by gas atomization (GA) and plasma rotating electrode process (PREP), respectively. For the GA and PREP powders, the powder characteristics, such as chemical composition, particle size distribution (PSD), powder morphology and powder defects are initially characterized and compared. Parallel single-track experiments and cuboid components printing have also been designed and carried out in the LPBF process by using these two types of powders. Forming quality and mechanical properties of different components are systematically evaluated. The results show that the powder feedstocks do not significantly affect the mechanical properties under the optimized LPBF process parameters. However, the PREP powder, with smooth surface, higher sphericity, higher apparent density and better flowability, can obtain a larger processing window and more stable mechanical properties of the as-built parts than the GA powder.