Particle Method for Simulation of Selective Laser Sintering Process

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Picture from: A coupled discrete element-finite difference model of selective laser sintering–Rishi Ganeriwala and Tarek I. Zohdi
Selective Laser Sintering (SLS) and Selective Laser Melting (SLM) are emerging as popular additive manufacturing processes due to their ability to create custom geometries in a vast range of materials such as polymers, composites, and most notably, metals. These processes work by repeatedly depositing a layer of material powder onto a print bed and utilizing a laser to either sinter or melt the layer of particles in a selected region such that it forms the cross-section of the desired geometry. While it provides much functionality, it is currently limited due to large defects that are frequent and inconsistent in even simple geometries. Furthermore, parts fabricated from this process almost always require some form of post processing to address macro and microscope defects and to create features that were not feasible with the SLS/SLM process. Understanding how the controllable parameters of this process can be optimized is essential for the industry to better trust this versatile manufacturing process for a wider scale of applications. This can be done through numerical simulation of these manufacturing processes. This dynamic and multiphysics nature of this process cannot be modeled using standard FEM packages as it would be too computationally expensive. I am focused on discretizing the manufacturing process into each of its physical parameters through the use of meshless particle-based methods such as the Discrete Element Method. In doing so, I can begin modeling this process by implementing a kinematic simulation of the deposition of the particles as well as a thermodynamic simulation of their heating by lasers. Moving forward, I hope to model other aspects of the process such as the laser physics and the effect of geometry on subsequent layer formation.