Fused deposition modeling (FDM) is a widely used manufacturing process and the materials market is growing due to the increased requirements on materials. In particular, processing of high‐temperature materials such as PEEK is challenging. The aim of these studies is to investigate and improve the processability of a carbon fiber reinforced polyether ether ketone (PEEK) material in the FDM process. The first step is to define the relevant process parameters, which remain constant over the entire investigation. In particular, the material‐specific temperatures must be defined. Based on previous investigations regarding the weld seam strength and the warpage of the selected PEEK materials, a method to determine and adjust essential process parameters should be developed. One approach is the consideration of the volumetric polymer discharge at a stationary filament feed rate. The optimized adjustment of the feed rate ensures increased component densities and an improved process reliability. In this context, the component areas with non‐stationary extruder movement, such as in corner areas, have got a huge influence on the component quality. The acceleration and deceleration processes do not result in a desired uniform strand geometry due to the pressure changes within the nozzle. The acceleration can result in thinner strands while the deceleration can lead to a thickening of the polymer discharge. The aim is to adjust the pressure inside the nozzle depending on the acceleration profile to enable a homogenous strand geometry. The method should therefore allow the improvement of the processability of PEEK materials.

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Due to the great popularity of the fused deposition modeling (FDM) process, more and more new materials become commercially available. The functionality of the FDM process allows the use of multiple materials, and this is known as multi-material printing. By integrating different materials into one component, component properties, such as mechanical properties like tensile strength, can be influenced. The aim of this study is to develop a procedure for assessing the suitability of different materials for multi-material printing in the FDM process. This enables the evaluation of different material combinations for the FDM process. The analysis of the material suitability for multi-material applications in the FDM process is carried out with the help of the evaluation of the weld seam quality. In this regard, a test method as well as test specimens are used, which ensure an evaluation of the processing suitability of different materials which is independent of the machine as well as the data preparation. In addition, suitable conditions must be defined for manufacturing the test specimens using two different materials. Single-strand test specimens are used in order to be able to draw conclusions about the weld seam quality. The weld seam quality is evaluated in relation to varying nozzle temperatures and build chamber temperatures. Finally, the suitability of the materials for multi-material applications in the FDM process are evaluated.

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