Development of a two-sided coupled material model for the characterization of ideal process parameters of application-optimized foams

• Applicants: Professor Dr.-Ing. Stefan Diebels; Professorin Dr.-Ing. Anne Jung
• Subject Area: Coating and Surface Technology ; Synthesis and Properties of Functional Materials ; Materials in Sintering Processes and Generative Manufacturing Processes ; Mechanics
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 423793605

• Final Report Year: 2023

Final Report Abstract

Application-optimised materials such as cellular media offer greater sustainability and cost savings than previous materials. This motivated the coating of open-cell PU foams using electrodeposition to create hybrid foams. Mass transport limitations cause significant coating inhomogeneities during the electrodeposition process. In this project, the parameters influencing the electrodeposition process were determined and optimised. The flow-controlled, electrochemical process was scaled up to sample sizes of 210 mm in diameter and a thickness of 40 mm as part of the project. The aim was to develop a two-sided coupled macroscopic material model to describe the electrode positioning process. To further develop the electrodeposition process of PU foams, an electrochemical coating cell was built and foams were coated using different parameter sets. A new method for the semidestructive determination of the coating thickness of hybrid foams was used for a time- and cost-efficient method of measuring the coating thickness. A test rig for Hall probe measurements and panoramic microscopy was set up for this purpose. The influence of the parameters velocity, diffusion constant, electric field and sink constant on the electrodeposition process and on the resulting coating thickness homogeneity were formulated with the aid of a unilaterally coupled macroscopic material model. The material model was implemented and the electrodeposition process simulated. In addition to the project, an artificial, stochastic structure of an open-cell foam was also produced in co-operations, which can be printed in reproducible quality using a new type of 3D printing technology. By using the same geometry, characterisations with greater comparability can be carried out in the future so that the manufacturing conditions can be improved even further.

Publications

• Konstruktion eines Durchflussversuches zur Ermittlung der Permeabilität von Schäumen
  John, K.
  
• Wärmebehandlung von Ni/PU-Hybridschäumen und Untersuchung der Auswirkungen auf Gefügestruktur und makromechanische Eigenschaften
  Fries, M.
  
• Applicability of correlated digital image correlation and infrared thermography for measuring mesomechanical deformation in foams and auxetics. GAMM-Mitteilungen, 45(3-4).
  Grednev, Sergej; Bronder, Stefan; Kunz, Francesco; Reis, Martin; Kirsch, Susanne‐Marie; Welsch, Felix; Seelecke, Stefan; Diebels, Stefan & Jung, Anne
  
• Investigation of the Structural Coating Homogeneity in Open‐Porous Nickel/Polyurethane Hybrid Foams Produced by Flow‐Controlled Electrodeposition. Advanced Engineering Materials, 24(11).
  Kunz, Francesco & Jung, Anne
  
• Korrelation der mikroskopischen Beschichtungsdicke von offenporigen Hybridmetallschäumen mit computertomographischen Aufnahmen und ihrer magnetischen Remanenz
  Lindner, L.
  
• Evaluation of a Local Acoustic Resonance Method for Coating Thickness Determination on Stochastic Metal Hybrid Foams. Advanced Engineering Materials, 26(24).
  Kollmannsperger, Lea S.; Kunz, Francesco; Becker, Michael M.; Jung, Anne & Fischer, Sarah C. L.
  
• Remanent Magnetic Field Scanning of Coating‐Graded Hybrid Foams. Advanced Engineering Materials, 26(24).
  Kunz, Francesco; Ibrahim, Bashar; Becker, Michael M.; Gao, Haibin; Fischer, Sarah C. L. & Jung, Anne