Production of Hybrid Lightweight Structures Through Al-Al Compound Casting with Additively Manufactured Lost Sand Moulds

This study investigates process variables influencing metallic bonding between aluminum wrought alloys and an aluminum casting alloy in compound sand casting. One is based on the casting design, and the other uses a coating on the sheet metal insert. An aluminum alloy EN AC-42100 is cast onto an aluminum sheet of EN AW-5754 and EN AW-6082, in each case without and with an insert coating (electroless nickel) at 720 ℃ or 760 ℃, to investigate the metallic bond in compound sand casting. A shear tensile sample was selected as test geometry only to enable a metallic bond. Compressive and optical microscopy samples were taken from the casted test geometry for further investigation. The results show that the coating favors a metallic bond, and in combination with a casting temperature of 760 ℃, strengths of up to 60 MPa were achieved. However, the optical images indicate that a sufficient metallic bond can be achieved without coating by designing a proper casting design. The key findings are transferred to a battery tray for automotive vehicles to demonstrate the applicability of the compound sand casting process as an alternative joining process.