Metal Additive Manufacturing Conference - MAMC 2020

Additive manufacturing using Laser Powder Bed Fusion (LPBF) provides breakthrough new capabilities in the fabrication of metallic components for a variety of applications. Nevertheless, major challenges remain. These include long process times, limited process robustness and thermal stress. Currently, LPBF process parameters are set globally for the entire part to be build, and do not take into account the individual geometric properties of the part.

At Fraunhofer ILT an approach is being made for the dynamic adaptation of LPBF process parameters to the part geometry. The objective is to increase component quality, process speed and process robustness. The geometric properties of the part to be manufactured are represented by a pixel model, so that the process parameters are adapted depending on the properties of each pixel. The associated model takes into account both the energy input within the current layer through the characteristic sequence of scan paths as well as the influence of already built areas in deeper layers of the part. This results in a targeted adaptation of the process parameters to the component geometry, which is made possible by an adapted machine control technology.

In this work, the development of the geometry-specific process control is presented using the example of the material Ti6Al4V. The model for the analysis of the geometrical properties of the part, the improvements achievable in comparison to the state of the art in terms of component quality, producible overhangs and productivity increase as well as the necessary control-technical adjustments are discussed.