Einfluss des Pulverauftragsprozesses auf den selektiven Strahlschmelzprozess thermoplastischer Kunststoffe

Abstract

The additive component manufacturing by selective beam melting of thermoplastic polymer powder consists of the sub-processes powder application, exposure and material consolidation. The achievable mechanical and geometrical component properties depend to a large extent on the interactions of these sub-processes with each other and the used material system. To increase process reproducibility and component quality a basic understanding of various interactions between sub-processes and specific material behavior is of high importance. In particular, the influence of the powder application, e.g. the deposition rate of different mechanisms (roller or blade) on the beam melting process and the resulting component properties is described insufficient. In the following article, the influence of the layer application on the thermodynamics of the beam melting process is analyzed. For this purpose, in particular temperature, respectively, the cooling rates, between new applicated and prior exposed powder is investigated. Furthermore a comparison with the thermal processing window of the PA12 material system, which is determined for varying cooling rates by means of differential scanning calorimetry (DSC), is performed. By analyzing the varying deposition rates the degree of supercooling of exposed layer is examined. Thus, a basic understanding of the influence of varying powder application parameters on the beam melting process is established.