Selektives Strahlschmelzen von Polymer-Blends: Prozess- und Werkstoffanforderungen

Abstract

In recent years the requirements on products concerning their degree of customisation and specialisation have raised. Because of the trend towards individualised parts a higher flexibility is expected from the used production process. Additive manufacturing processes fulfil this advanced profile of requirements on the process technology. But the severely limited variety of materials usable for the selective laser melting of polymers inhibits the penetration of the market of this production technique at the moment. The enlargement of the usable range of materials e.g. with polymer blends represents a crucial innovation. In context of the shown investigations initially the principle suitability of blend systems for processing in powder and beam based processes is examined, in this particular case by means of selective laser melting. As part of this the process and material requirements on possible polymeric material systems are worked out, with the goal to find material combinations which can be processed within powder and beam based additive processes. By means of concrete mixtures of two polymers the producibility of the process is checked. In the framework of processing experiments on single layer respectively single line basis polymer blends consisting of polypropylene (PP)/polyoxymethylene (POM) as well as PP/polyamide (PA12) in different mixing ratios are processed. The resulting molten layer thickness and the fusion line width allow conclusions concerning the beam-powder-interaction. In addition the resulting phase morphology is analysed on the basis of thin cuttings. The presented investigations connect the selective beam melting with the blend technology so that the tool-free production of individual components with a specific and adapted to the respective application profile of properties will be possible.