DEM Simulation of Powder Bed Spreading for Additive Manufacturing of Functionally Graded Components

  • Choudhury, Shakti Swaroop (Indian Institute of Technology Madras)
  • Annabattula, Ratna Kumar (Indian Institute of Technology Madras)
  • Amirthalingam, Murugaiyan (Indian Institute of Technology Madras)

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Laser powder bed fusion (LPBF) produces components that are difficult to create using traditional techniques and has revolutionised manufacturing science. Manufacturing end-user components using powder bed fusion from a single material is well-established. Functionally graded materials offer several technological advantages over homogeneous materials due to their unique ability to offer properties that are mutually exclusive such as strength and ductility. Hence, using the powder bed fusion method to create functionally graded material (FGM) parts opens up new design opportunities. The recent studies on the partition-based approach to develop FGM are still in their infancy. The spreading quality prior to laser solidification is better understood by the simulation of powder spreading. When numerically characterising discontinuous media, such as powder particles in PBF, the discrete element method (DEM) is helpful. To spread a uniform layer of powder with the best spreading parameters can be easily selected using simulation tools like DEM. By using the DEM to solve optimisation issues, the mechanism explaining the physics and dynamics of multi-material interaction can be achieved, lowering the need for costly and time-consuming experimental campaigns. In the current study, functional gradation along the spreading direction was accomplished using a partition-based strategy. The main goal of this work is to create a spreading approach for the powder bed fusion process that will enable us to acquire the appropriate graded material dispersion prior to laser melting. It was investigated how various recoater geometries affected the evolution of the material's functionally (compositional) gradation. The recoater speed and shape dependency on the evolution of FGM spread was also studied.