Comparison of the Mechanical Properties of Adhesively Bonded and Mechanically Interlocked Steel/Fibre-Reinforced Thermoplastic Hybrids Produced Using One-Step Forming Process

The continuous increase in the weight of newly registered vehicles is in conflict with the targeted reduction in greenhouse gases emission and fuel consumption imposed by several environmental regulations. To meet these stringent environmental regulations, the fabrication of hybrid structural parts is a particularly suitable alternative for mass-produced vehicles. Through the combination of fibre-reinforced thermoplastics (FRTP’s) and steels, an optimum of component costs and weight savings can potentially be achieved. However, the production of hybrid components traditionally involves additional manufacturing steps and a subsequent joining processes. In order to increase the efficiency of the hybrid production process, both materials can be formed and joined together in one forming step. In this paper, two different approaches to join FRTP and steel sheet in a single forming step are compared in respect of their mechanical strength. For this, structured steel sheets designed to obtain mechanical interlocking and an adhesive film are used. Furthermore, process parameters such as forming force, blank holder force and tool temperature are varied during the manufacturing process to determine their influence on the mechanical performance.