Material Behaviour and Process Analysis in Laser Sintering of Thermoplasts
Additive Manufacturing technologies like Selective Laser Sintering (SLS) give the possibility to produce complex structures and products with a high degree in individualization in a flexible way. Especially in the field of medical applications as well as the automotive and aviation sector the technological advantages can improve the current state of the art. Up to now this potential is not yet utilized, as this technology is still limited by means of part reproducibility and available materials.
The production of parts in a layerwise way of melting polymer powders combines complex questions in powder coating, energy insertion and material consolidation. Also due to the limited materials spectrum there exist much idealized models for those sub-processes, which cannot represent the running processes in reality. In general it can be observed that space- and time-resolved process conditions and phase changes cannot yet be monitored in current machine technologies. A correlation between process and resulting morphology in components and thus prediction of final part properties is not possible.
This work treats the widening of material spectrum by means of alternatively usable materials and their processing behavior in order to derive a fundamental knowledge of the process. The spectrum of materials contained the available Polyamide12 (PA12) laser sintering powder but also Polypropylene (PP), Polyethylene (PE) and Polyoxymethylene (POM) which were adequately conditioned in order to process it to parts and analyze their capability for the laser sintering process. Besides the rheological properties of different powder the special focus of the work is on the quasi-isothermal processing conditions while the built-up of components.
This creates a basis to model and simulate the (thermal) conditions in a laser sintering machine with the aim to predict the geometrical and mechanical part properties in long-term view. The findings are utilized to propose a new time-dependent laser-sintering model and to show the potential of new materials (e.g. Polylactide) and methods of conditioning (e.g. tempering and fiber spinning).Lesen Sie die deutsche Zusammenfassung auf Kunststoffe.de
Laser Sintering, Additive Manufacturing, Quasi-isothermal Prozessing, Thermoplastic Powders, Polyamide
Institute / chair: Technische Fakultät der Universität Erlangen-Nürnberg
Technical consultant for expert services: Prof. Dr.-Ing. Dietmar Drummer (Betreuer), Prof. Dr.-Ing. Gerd Witt, Magnifizenz Prof. Dr.-Ing. Ernst Schmachtenberg, Prof. Dr.-Ing. Dr. h.c. Gottfried W. Ehrenstein
Publication year: 2011
Provider: Wissenschaftlicher Arbeitskreis Kunststofftechnik (WAK) / Kunststoffe.de
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