TY - CHAP A1 - Laumer, Tobias A1 - Schmidt, Michael A1 - Stichel, Thomas T1 - Influence of temperature gradients on the part properties for the simultaneous laser beam melting of polymers T2 - Proceedings of Laser in Manfacturing Conference 2015, June 22 - June 25, 2015 Munich, Germany N2 - By Laser Beam Melting of polymers (LBM), parts with almost any geometry can be built directly out of CAD files without the need for additional tools. Thus, prototypes or parts in small series production can be generated within short times. Up to now, no multi-material parts have been built by LBM, which is a major limitation of the technology. To realize multi-material parts, new mechanisms for depositing different polymer powders as well as a new irradiation strategy are needed, by which polymers with different melting temperatures can be warmed to their specific preheating temperatures and be molten simultaneously. This is achieved by simultaneous laser beam melting (SLBM). In the process, two different materials are deposited next to each other and preheated a few degrees below their melting temperatures by infrared emitters and laser radiation (λ = 10.60 µm), before in the last step the two preheated powders are molten simultaneously by an additional laser (λ = 1.94 µm). So far, multi-material tensile bars have been realized and analyzed regarding their boundary zone between both materials. The experiments showed that the temperature gradients in the boundary zone and along the building direction seem to be of great importance for the process stability and the resulting part properties. Therefore, a detailed analysis of the occurring temperature gradients during the process is needed to identify adequate process adjustments regarding the temperature controlling. To analyze the temperature gradients, thermocouples positioned inside the powder bed are used. By varying the temperature of the building platform, the influence of different temperature gradients on the resulting part properties is shown. KW - additive manufacturing KW - laser beam melting of polymers KW - multi-material parts Y1 - 2015 UR - https://www.wlt.de/lim/Proceedings/Stick/PDF/Contribution241_final.pdf ER - TY - CHAP A1 - Laumer, Tobias A1 - Koopmann, Jonas A1 - Stichel, Thomas A1 - Amend, Philipp T1 - Generation of multi-material parts with alternating material layers by Simultaneous Laser Beam Meltingof polymers T2 - International Conference on Additive Technologies, 15 - 17 Oct 2014, Wien N2 - By using Additive Manufacturing technologies, like Laser Beam Melting (LBM) of polymers, parts can be realized within single days and necessary modifications can be quickly adapted. With increasing complexity, products are often made out of different polymer materials and the need for multi-material parts is an increasing industry requirement, which cannot be fulfilled by the single material parts realizable by LBM. Therefore, Simultaneous Laser Beam Melting (SLBM) as a new Additive Manufacturing technology offers the possibility to build parts consisting of different polymer materials. The realizable parts combine different material properties, like differing stiffness or chemical resistances, within a single part. Up to now, different materials are deposited next to each other on the building platform, thus the boundary surface between the different polymers is orientated perpendicular to the building direction. For this paper, the polymer powders are alternated in building direction. Thus, the boundary surface is orientated horizontally and is larger, both influencing the boundary surface and resulting part properties, which are analyzed by a high-resolution thermal imaging system and by cross sections. KW - additive manufacturing KW - Multi-Material Parts KW - Simultaneous Laser Beam Melting Y1 - 2014 UR - https://www.researchgate.net/publication/274250275_Generation_of_multi-material_parts_with_alternating_material_layers_by_Simultaneous_Laser_Beam_Meltingof_polymers ER -