Abstract

A finite element model has been developed for the 3D simulation of the sintering of a single track during a selective laser sintering process (SLS). The model takes into account both the thermal and the sintering phenomena involved in the process. Owing to the continuous movement of the laser beam the model takes also into account the transient nature of the problem. This is transformed into a pseudo‐static one through a transformation of the coordinates system of the equations. Nevertheless, this transformation introduces a convective term into the heat equations that produces instabilities in the solution. These instabilities have been solved by using a stream upwind Petrov Galerkin (SUPG) strategy together with a shock capturing scheme. Finally, a fixed point strategy is used for the solution of the analysis. The model has been tested through the solution of some examples.

Abstract

One of the larger growing fields within additive manufacturing is the selective laser sintering process of semi-crystalline polymer powders. The powder is locally fused at certain areas, due to the energy output of a laser. This method allows for rapid production of complex parts, which are well suited for prototyping. The overall accuracy and stability of the process along with part properties are highly related to the process parameter. A better control of these parameters will therefore optimize the process even further. The current paper propos a numerical modelling approach and the model makes it possible, to analyze the influence of the laser-related input parameters concerning the temperature distribution and size of the melt pool. For the validation, certain outputs from the model are compared to the ones found from experimental single-line track data, where the melt pool geometry can be compared to the numerical measurements.