Powder Bed Spreading in Additive Manufacturing: Numerical Simulations and Experimental Study

Powder bed based additive manufacturing technologies allow for the production of more complex parts with overall better characteristics and are therefore of high industrial interest. However, due to an incomplete understanding of the multi-physic processes involved there are still some issues to be addressed. More specifically, in this work we will focus on the powder spreading stage. In powder bed-based technologies a thin layer of powder is deposited by a recoating device and is then processed by an energy source to obtain a layer of the final part. We use a numerical model based on the Discrete Element Method to reproduce the spreading process and propose an experimental analysis procedure to obtain data suitable for the validation of such numerical model. The experiments are carried out on a purposely designed device and both computations and experiment are referred to a single layer deposition. Being able to validate the numerical results can give way to a more confident use of DEM based models for the optimization of the spreading process and therefore improve the quality of printed parts. (Abstract)