Large sandwich sheets enabled by joining rolled sheets and additively manufactured core structures for forming

Abstract

To overcome the size limitations of conventional laser-powderbed fusion (L-PBF) machines, a new methodology to manufacture large sandwich sheets by joining rolled sheets with additively manufactured core structures is developed, which potentially can be used as parts with a high amount of functional integration for heat exchanger systems or battery housings. Different joining mechanisms are directly applied to the core structure and tested for their strength in shear- and bending-experiments. Design guidelines for L-PBF are especially important to guarantee good geometrical accuracy of the joining mechanisms. The joint strength exceeds the face sheet material strength with certain geometric parameters. A process window is developed showing that bending of the joined sandwich sheets is possible up to a bending radius R to sandwich sheet height H ratio of R/H = 3.33. The global axial compliance of the buckling-joining mechanism leads to an increased overlap of the joining mechanism and the face sheet, thus a high bonding strength is achieved.