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Continuous Fiber Reinforced Thermoplastic (CFRT) hybrid parts offer interesting possibilities for lightweight application, which can exceed the capabilities of mono material metal or CFRT parts. In this case, the joining technology oftentimes is the limiting factor. This study investigates a joining operation with metal pin structures which are additively manufactured via powder bed fusion featuring different diameters and tip geometries, which are inserted into the locally infrared heated CFRT part. The resulting fiber rearrangement is assessed using transmitted light microscopy, confocal laser scanning microscopy as well as micro-computer-tomography. It could be shown that for all assessed pin variants a similar distinct fiber displacement can be seen and that the pin diameter has a significant effect on the resulting fiber orientation with smaller pin diameters being advantageous because of gentle fiber displacement and reduced undulation. The tip geometry has only minor effect on the fiber orientation. Especially in the X/Y plane no systematic influence of the tip geometry on the fiber displacement could be observed. Based on the gained insights a three-stage model of the fiber orientation processes is proposed.

The production of components consisting of various polymer types by welding is severely restricted and only possible for bonding compatible materials with melting points in a close range. Several modifications, such as the cross-linking of one joining partner, allow for circumventing the restrictions regarding the melting points but do not help in joining bonding incompatible materials. Investigations of dissimilar material combinations, especially from polymer-metal hybrid structures, show a high potential of connections based on form fits. Within the scope of this paper, the possibility of joining incompatible polymer combinations, such as polyamide 66 and high-density polyethylene, by micro form fit using the vibration welding process is analyzed. For this purpose, the generated bonding strength of the test specimen was determined by shear tests. Furthermore, the undercuts of the generated prestructures and the resulting bond of the test specimen were examined microscopically by computer-tomography. These investigations depict the high potential of joining incompatible polymer combinations by form fit in the vibration welding using prestructuring to generate undercuts.

Forming processes of continuous fiber reinforced thermoplastic materials are oftentimes limited to high volume production due to the high costs for tooling and processing machines. This study suggests the combined use of a cold and simple tool and high forming speeds to reduce tooling and processing costs and enable the usage of common stamping machines. Half sphere samples are produced from single and two-layer polypropylene and glass fiber organo-sheets in a custom built drop tower and analyzed for their geometry, degree of re-consolidation, surface quality and potential fiber damage using a variety of microscopy techniques. While only mediocre degrees of reconsolidation and limited surface qualities can be achieved with the combination of a cold tooling and state-of-the-art forming speeds of 0-0.5 ms −1 , the usage of a higher forming speed of 3 ms −1 , vastly improves surface qualities and the degree of reconsolidation without any detectable fiber damage. This effect is more pronounced in the dual layer material. Extensive knowledge on the forming behavior of continuous fiber reinforced thermoplastics at high cooling rates and high speeds of deformation is required for sufficient process control and future studies need to further elaborate and quantify the influencing factors and limits of high-speed forming of continuous fiber reinforced thermoplastics.

Abstract One method to produce electronic systems with high resilience is the encapsulation of metal inserts, for example, lead frames, using assembly injection molding. Such parts are exposed to different mediums, such as water and oil, which can infiltrate and damage the electronic system, especially in automotive applications. Hence, one challenge is to ensure the tightness. The research covered in this paper focuses on the assembly injection molding of tight electronic systems using microstructured metal inserts, manufactured by a two-stage electrochemical treatment. The effects of the electrochemical treatment on the tightness and the bond between metal and polymer of the electronic system are investigated. Furthermore, the influence of the electrochemical treatment on the surface and geometry of the metal insert is evaluated.