JEC World 2019 preview: Fraunhofer IPT

Fraunhofer Institutes for Production Technology (IPT, Aachen, Germany, 5/D17) is emphasizing work it did with Fraunhofer Institute for Laser Technology (ILT, Aachen) on the EU research project ComMUnion, in collaboration with 14 partners from industry, to develop industrial processes and solutions for hybrid lightweight design by combining metal and polymer-matrix composites for automotive and aerospace applications.

Fraunhofer IPT says he new hybrid manufacturing process is based on a combination of laser texturing and laser-assisted tape placement: For this purpose, components are first pre-processed using the laser to provide a specially developed, defined, rough surface structure. The textured surface allows the continuous fiber-reinforced thermoplastic lightweight materials, which will later be used for stiffening, to be bonded directly to the steel component. The bond is then mechanical, eliminating any need for additional pre-treatment measures or additional adhesion promoters, such as adhesives or bonding agents.

The stiffeners, made of thermoplastic fiber-reinforced composites, which are especially adapted to the expected loads, are joined to the component using a tape placement process. The laser heats the thermoplastic tapes locally in the joining zone to the steel. The matrix material melts and flows into the laser-textured cavities. After solidification of the melt material, the tape with the embedded unidirectional fibers adheres to the roughened surface of the steel part.

The advantage of combining these two laser processes, says Fraunhofer IPT, comes to the fore when the mechanical properties of the component needs to be improved locally without increasing the component’s weight significantly. The process, says Fraunhofer IPT, is particularly suitable for mass production, as no further post-processing steps, such as curing operations, are required to consolidate the material after tape placement. Additionally, precise, localized heating is said to reduce distortion and residual stresses while joining the two materials. The laser texturing process, which has been developed at the Fraunhofer ILT, can also be applied in a reproducible way to the metal surface at the locations where the textures are needed. Additionally, the laser is not subject to any tool wear.

To prove the viability of the process, research partners have finished a first demonstrator component made of high-strength steel and unidirectional fiber-reinforced thermoplastic tape: The two Fraunhofer researchers, Kira van der Straeten from the Fraunhofer ILT and Tido Peters from the Fraunhofer IPT, manufactured a hybrid lightweight rocker panel, a body component for the automotive industry, to test and prove the functionality of the process combination as part of the ComMUnion project. This component will be on exhibit in the Fraunhofer stand.

The ComMUnion project is funded by the Horizon 2020 Research and Innovation Programme of the European Union under Grant Agreement No. 680567.

European partners of the ComMUnion research project are:

• Aimen Technology Centre, Spain (coordinator)
• Autotech Engineering, AIE, part of the Gestamp Group, Spain
• AFPT GmbH, Germany
• New Infrared Technologies SL, Spain
• Tecnatom SA, Spain
• Motofil Robotics SA, Portugal
• Philips Photonics GmbH, Germany
• Laboratory for Manufacturing Systems and Automation (LMS) – University of Patras, Greece
• Universidade de Coimbra, Portugal
• Missler Software, France
• Aciturri Engineering SL, Spain
• CASP SA, Greece
• Lunovu GmbH, Germany
• ESI Group, France