Melt in powder bed
The process of selective laser melting can be divided into three sub-processes: material application, energy application and material consolidation. First, by means of a roller or a doctor blade system, the application of a powder layer in the construction space takes place, which is then heated up to just below the melting point of the material. A CO2 laser then illuminates the melted cross section of the component. The surrounding powder remains loose and serves as a support structure. The space decreases after the exposure process to the thickness of a layer, usually 100 microns, and a new powder application begins. This process is repeated until the entire part is successively constructed. Only after all the layers of the component have been generated is the powder cake with the internal components cooled.
Simulation of the energy-contribution through the laser
The properties of beam-molten components, such as the density, surface topography, detail and contour accuracy, are determined by the interaction of the material with the processing parameters. In addition to the application behavior of different powders and the resulting packing density, the temperature control as well as the energy input play a significant role in the part production.
One focus of the process analysis at the Department of Polymer Engineering is the correlation of the processing control with the formed morphological structure in the component and the resulting component properties. Based on the researched interactions between materials, process and component level, conclusions can be drawn on the expected component properties with the help of simulations. The findings from the analysis of process interactions also allow processing control focused on the individual material properties.