Project Details
Projekt
Forming of additively manufactured sandwich sheet composites with optimized core structures
Subject Area
Primary Shaping and Reshaping Technology, Additive Manufacturing
Term
from 2016 to 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 317137194
Sandwich composites enable optimum utilization of the used materials to achieve high strengths and stiffnesses. The possibility of integrating additional functional elements facilitates a high degree of lightweight construction. The hitherto used process route of additive manufacturing of sandwich sheets and subsequent forming to obtain the final semi-finished sandwich part allows for the production of highly complex sandwich components through the efficient utilization of the synergy effects of the two manufacturing processes. In this research project, with the aim of further increasing the productivity, additively manufactured core structures with integrated functional elements and shape-adapted geometry will be joined with the outer cold-rolled sheets to form hybrid semi-finished products. Material and form-fitting joining methods will be tested. A special feature is the development of a joining process, which allows for joining after or during the forming operation in order to reduce or even avoid shear stresses that occur between the cover and core layer. With the help of experimental investigations and numerical topology optimization, core geometries which are apt for subsequent forming will be developed. This requires highly ductile materials as well as extensive knowledge of the elastic-plastic material behavior and prevailing anisotropies. In order to expand the formability of additively manufactured parts, a high-manganese steel (TWIP-steel) which is yet untested for additive production is to be qualified and extensively characterized. To further increase the formability of this material, an ex-situ alloying of the powder to promote the TWIP effect will be carried out. Occurring anisotropies should be reduced to a minimum by in-situ heat treatment and suitable process control. The newly developed material and novel joining methods will enable the large-scale production of semi-finished sandwich products with integrated functional elements that can be subsequently transformed into functional net-shaped components.
DFG Programme
Research Grants
Co-Investigators
Dr.-Ing. Soeren Gies; Dr.-Ing. Stefan Kleszczynski
