The Flow Cell Concept for the Metallization of Complex Geometries in Aerospace High-End Applications
Authors: Rafailovic Lidija D. , Haas Catherine , Nixon Sonja , Shayna Slobin , Rohr Oliver , Trisovic Tomislav Lj. 
Published: December 2024

Since the discovery of carbon fiber reinforced polymers (CFRP) as composite materials with advantageous performance-to-weight ratios, many advanced applications, particularly in the aerospace field, have emerged [1]. The excellent mechanical properties and corrosion resistance of CFRPs are of particular interest to the transportation industry, where significant savings due to weight reduction can be accomplished. Recent research efforts consolidate several functions into a single material by developing synthesis approaches that offer energy savings and the more efficient use of materials, while preserving the structural integrity of the material [2]. CFRPs are considered one of the best choices for this purpose, but additional steps must be considered in the design or in the post-use of composites [2–4]. In this context, metallization of CFRP emerged as a pivotal for high-end applications. The opportunities presented by employing electrochemical methods, such as electroless and electrochemical deposition, stand out among other metallization methods as cost-effective, scalable, and particularly convenient for complex CFRPs geometries. However, challenges in adapting plating conditions to different geometries with high inner aspect ratios require new solutions and more efficient use of electrolytes [5]. We demonstrate electrochemical engineering through the introduction of the flow cell concept for electroless and galvanic plating across various geometries and applications. Simultaneously, ensuring environmental compliance of the chemical pre-treatment process of composites is achieved by developing Cr(VI)-free chemistry adapted to the composite being used.

References:

[1] Julian Adam, T.; Liao, G.; Petersen, J.; Geier, S.; Finke, B.; Wierach, P.; Kwade, A.; Wiedemann, M. Multifunctional Composites for Future Energy Storage in Aerospace Structures. Energies
2018, 11(2), 335.

[2] Kaynan, O.; Hosseini, E.; Zakertabrizi, M.; Motta De Castro, E.; Pérez, L. M.; Jarrahbashi, D.; Asadi, A. Multifunctionality through Embedding Patterned Nanostructures in High-Performance Composites. Advanced Materials
2023, 35 (32), 2300948.

[3] Rafailović, L. D.; Stupavska, M.; Prysiazhnyi, V.; Polt, G.; Rohr, O.; Nixon, S.; Rahel, J. Impact of Atmospheric Pressure Plasma Treatment on Surface Metallization of CFRP Composites. Surf Coat Technol
2021, 412, 127046.

[4] Rafailović, L. D.; Jovanović, A. Z.; Gutić, S. J.; Wehr, J.; Rentenberger, C.; Trišović, T. L.; Pašti, I. A. New Insights into the Metallization of Graphene-Supported Composite Materials-from 3D Cu-Grown Structures to Free-Standing Electrodeposited Porous Ni Foils. ACS Omega
2022, 7 (5), 4352.

[5] Rafailovich L.; Nixon S.; Haas C.; Trisovic T.; Karnthaler H. P. Apparatus and Method for Continuous Metallization of Object, EP3540098A3, US11098412B2.

Acknowledgments:

LDR acknowledges support provided by Montanuniversität Leoben. This work was partially supported at CEST within the COMET program by the Austrian Research Promotion Agency (FFG) and the governments of Lower and Upper Austria.