Optimized build orientation of additive manufactured parts for improved surface quality and build time

The layered structure of Additive Manufacturing processes results in a stair-stepping effect of the surface topographies. In general, the impact of this effect strongly depends on the build angle of a surface, whereas the overall surface roughness is additionally caused by the resolution of the specific AM process. The aim of this work is the prediction of the surface quality in dependence of the building orientation of a part. These results can finally be used to optimize the orientation to get a desired surface quality. As not all parts of the component surface are equally important, a preselection of areas can be used to improve the overall surface quality of relevant areas. The model uses the digital AMF format of a part. Each triangle is assigned with a roughness value and by testing different orientations the best one can be found. This approach needs a database for the surface qualities. This must be done separately for each Additive Manufacturing process and is shown exemplarily with a surface topography simulation for the laser sintering process. A validation of the model is done with a monitor bracket of EOS GmbH. Measurements of five different orientations of the part, optimized according selected surface areas, show a good accordance between the real surface roughness and the predicted roughness of the simulation. (C) 2016 Elsevier B.V. All rights reserved.