Enhancement of thin hot-stamped components using fiber-reinforced plastic structures with improved fatigue strength characteristics

The automotive industry has high demands for multi-material structures in achieving lightweight design, efficient body construction and enhanced functionality. These structures capitalize on the favorable mechanical properties and reduced weight of such combinations, especially when metal and plastic are integrated to create a synergistic effect. This research paper outlines the advancement of a hot-stamp and an compression tool to facilitate a thermally assisted compression process. This process enables the seamless joining of GMT (Glass Mat reinforced Thermoplastics) and 22MnB5 steel without the need for additional bonding agents. In the initial step of the process, a hot-stamping tool is utilized to fabricate cap profile components. Afterwards a combined compression and joining process of the GMT takes place. Through adhesion, the GMT material bonds to the rough surface of the AlSi-coated 22MnB5, enabling the removal of the final component. The influence of process parameters was assessed through static and dynamic tests conducted on demonstrator components. Overall, it was determined that the introduction of a GMT stiffening structure leads to improvements in both the static and dynamic properties of the component so a reduction of the steel thickness of the structure can be carried out. This reduction in thickness is accompanied by a decrease in the mass of the test structure, while maintaining or even enhancing its static and dynamic properties. Further weight savings are possible through additional component and process optimization.