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Description
Jie Lun Tan1 2 Chee How Wong1

1, Nanyang Technological University, Singapore, , Singapore
2, SLM Solutions, Singapore, , Singapore

Selective Laser Melting (SLM) is a powder bed fusion process in Additive Manufacturing (AM). Its freedom of design has given it an edge in the aerospace, automotive and medical manufacturing industry. With its wide range of applications, there has been an increasing demand for new materials to be incorporated in the SLM process. The optimized parameters for each material, such as laser power, laser scanning speed, hatch spacing and powder layer thickness, are commonly derived from experimental trial and error. With many parameters combinations, it can be expensive and time consuming to conduct experiments to find the optimum parameters which will give the best properties for the intended usage of the part. Since SLM requires a good interlayer bonding, the melt pool depth can be a good indicator of how well the current layer fuse with its previous layers. Modelling of the SLM process can be used to aid in this issue. Since SLM is a multi-physics process, there are many considerations when performing the simulations. In this paper, study of the melting of stainless steel 316L using a Computational Fluid Dynamics to observe the melt pool characteristics. As there are many experimental results on SS316L, they are used to validate the accuracy of the model. The simulation model allows the observation of the molten pool flow during the SLM process due to Marangoni’s effect and recoil pressure. Furthermore, different parameters are tested to show their effects on the melt pool and track formation. Different laser beam diameters, laser powers as well as scanning speeds were used to study the effects they have on the melt pool characteristics. The results were used to determine the relationships between these factors and the melt pool characteristics.

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