Springback Behavior of Carbon-Fiber-Reinforced Plastic Laminates With Metal Cover Layers in V-Die Bending

The V-die bending of a carbon-fiber reinforced thermoplastic laminate bonded to thin cover layers made of microalloyed steel was investigated. Such hybrid semi-finished products are gaining importance in transport-related lightweight designs. Experiments were conducted for different forming temperatures and dwell times to determine suitable process parameters. The punch radius was varied to evaluate its influence on the springback/negative springback of the fiber-metal laminate (FML). The results, which are in good accordance with a simple analytical model, showed that the solidification of the composite core can compensate for the springback of the metal layers. Micrographs further revealed that the fiber orientation can affect the thickness distribution in the bend area.