Composite properties in back-moulding metallic three-dimensional Surfi-Sculpt form-locking elements

Plastic/metal hybrid components combine the advantages of both materials, while optimising the weight-performance-ratio. In the HySurf project, the IKV is working in cooperation with the Institute for Welding and Joining Technology at RWTH Aachen University (ISF) to develop a methodology for predicting the failure behaviour of back-injected hybrid components with Surfi-Sculpt structures based on process and material parameters.

© IKV

When manufacturing plastic/metal hybrid components, the foreign materials can be connected by welding, glueing or integrated back-moulding, which often necessitates a form fit or primer. Form-fitting mechanisms, such as back-moulding Surfi-Sculpt structures, offer several advantages: They can be used independently of the material and allow the separation of the component in the context of Design for Disassembly. They also enable a more complex connection between metal and plastic through a combination of elevation and indentation. However, the precise design and positioning of these structures regarding melt pressures during back-moulding, different load directions during usage and separability at the end of life present a central challenge.

In cooperation with the Institute for Welding and Joining Technology at RWTH Aachen University (ISF), a methodology is developed to predict the failure behaviour of back-moulded hybrid components with Surfi-Sculpt structures, considering the material characteristics and processing conditions during structuring as well as back-moulding. To this end, various structural geometries in different orientations are created in and on the metal part before it is back-moulded in an integrated process. The produced plastic/metal hybrid components are mechanically and microscopically analysed to determine the influence of the structure on the bonding strength, weld line formation and breakage behaviour, using both experimental and simulation-based methods.

Project data and funding

We would like to thank the DFG for funding the project (funding reference HO 4776/101-1) and the project partners for
the cooperation.

Project duration: 01.07.2025 – 31.12.2025