Innovative coating technology for fusion power plants:
GalvanoFusion – an electrochemical process for tungsten coatings
A research consortium comprising the Max Planck Institute for Plasma Physics (IPP) and specialist electrolyte manufacturer IoLiTec, led by the Fraunhofer Institute for Manufacturing Engineering and Automation IPA, is developing a globally innovative technology for the electrochemical deposition of pure tungsten coatings.
The project, which runs until the end of 2028, aims to protect the inner walls of future fusion reactors – known as the first wall – with layers of tungsten. Due to its extreme heat resistance and robustness, tungsten is the material of choice for plasma-exposed surfaces that must withstand loads of up to 10 megawatts per square metre. As a so-called refractory metal, with a melting point above 3000 degrees Celsius, tungsten withstands even the most extreme thermal stresses. However, this rare material is scarce: comprising just one millionth of the Earth’s crust, it is classified as a conflict mineral and is extremely difficult to process mechanically. Manufacturing entire components from tungsten is therefore neither economical nor practical. The solution: a thin layer of tungsten on a more easily handled substrate.
Anhydrous electrolytes
The scientific challenge lies in the nature of the metal itself: conventional electroplating processes, such as those used in industry, are thwarted by a physical barrier: tungsten has a very low hydrogen overpotential. In aqueous electrolytes, therefore, no metal is deposited; instead, only hydrogen is produced. The research consortium is therefore breaking new scientific ground with anhydrous electrolytes based on ionic liquids and organic solvents. “There is no process in the world for the electrochemical deposition of pure tungsten – neither industrially nor in the laboratory,” emphasises project leader Andreas Waibel from Fraunhofer IPA.
The three partners contribute complementary expertise: The IPP defines the requirements for the coatings and carries out application-oriented tests under fusion-relevant conditions. The Fraunhofer IPA is developing the entire coating process with the aim of subsequent industrial scaling. IoLiTec contributes the know-how for formulating the special ionic liquids.
The project “GalvanoFusion – Electrochemical deposition of tungsten layers for fusion reactors from non-aqueous electrolytes” is funded by the Federal Ministry of Research, Technology and Space (BMFTR) as part of the Fusion 2040 – Research on the Path to a Fusion Power Plant, under grant reference number 13F1034A, with a duration from 1 January 2026 to 31 December 2028.
The plasma vessel of the ASDEX upgrade at the MPI for Plasma Physics in Garching near Munich, fitted with tungsten-coated tiles (Source: MPI für Plasmaphysik, Foto: V. Rohde)