Development of a high pressure die casting tool for partial integration of glass fiber structures

Due to the growing demand for lightweight solutions in a wide range of industries, the selection and combination of various materials is becoming more and more important. As a result, the need for suitable joining technologies is increasing along with it. Within the DFG research group "Schwarz-Silber" ("black-silver"), Fraunhofer IFAM is investigating so-called transitional structures in cooperation with the University of Bremen. In this process, glass fiber structures are integrated into aluminum by a high pressure die casting process. These structures are used for the electrochemical insulation between aluminum and carbon fiber textiles, which are connected by textile processes in a subsequent production step. A solid hybrid structure is finally achieved through a resin-impregnation process. The key challenges are the positioning, pre-tensioning and infiltration of the glass fiber structures within the high pressure die casting process. In order to meet these challenges, a customized die casting tool was developed within the project. With the aid of mold-filling simulations, the die system of the die casting tool was optimized to achieve better infiltration of the fiber bundles and to additionally support the position of the glass fibers in the casting process. After the design of the molding tool, the implementation was carried out in collaboration with a toolmaker. In subsequent, up-to-date investigations, the positioning and infiltration of different variants of glass fiber structures is evaluated. The results are compared with previous attempts to position and infiltrate the glass fiber structures to assess the effect of the optimized newly designed tool.