Anyone following the current debate surrounding the energy transition knows that a key prerequisite for its success is ensuring the safe and stable transmission of energy. Therefore, long-term stable current-carrying connections, for example at charging stations for electric vehicles or in gas-insulated switchgear, are of the utmost importance for the functional safety of energy systems and for the reliability of energy transmission.
To ensure that the precious metal-coated contacts used here remain intact even during high mating cycles - i.e. when they are plugged and unplugged very often - they are currently treated with contact lubricants. These reduce frictional wear during operation and enable the required, sometimes very long operating times. However, these lubricants have various disadvantages: they must be temperature-resistant and must be dosed very precisely, and they age, decompose and form residues over time, which increase contact resistance.
This is where a new research project entitled "Contact and long-term behavior of self-lubricating coatings in current-carrying connections in electrical power engineering" comes in. The aim is to develop galvanic silver dispersion coatings with self-lubricating properties. These new types of coatings should eventually render the subsequently applied lubricants liquid.
liquid. The two research partners, the Institute for Electrical Energy Supply and High Voltage Technology (IEEH) at the TU Dresden and the Schwäbisch Gmünd-based Research Institute Edelmetalle + Metallchemie (fem), recently met in Dresden at the kick-off event for the joint project, which is being funded by the Federal Ministry for Economic Affairs and Energy as part of the 7th Energy Research Program over a period of three years with a total of around 1.3 million euros.
1.3 million euros over a period of three years.
The interest and participation of industry is also very high: the joint partners Rosenberger Hochfrequenztechnik GmbH & Co. KG and Composite Coatings Services GmbH as well as the associated partners Henze BNP AG, Dr.-Ing. Max Schlötter GmbH & Co. KG, Siemens AG and Stäubli Electrical Connectors GmbH are working together with the research institutes on the development of the silver coatings, in which mainly so-called hexagonal boron nitride particles are to be embedded as a solid lubricant. At the fem, these coatings are produced on a laboratory scale. Simulation software helps the researchers to optimize the incorporation and distribution of these particles. A large part of the extensive characterization of the coatings - what is their friction behaviour, how good are their mechanical or thermal properties - also takes place at fem. The IEEH in Dresden, on the other hand, investigates the electrical properties of the coatings and carries out friction wear tests on real connectors. "Although the end result is not yet a market-ready product, the know-how of the industrial partners involved means that the dispersion layers can even be tested on industrial test specimens in technical applications towards the end of the project.
even be produced and qualified on industrial test specimens on a pilot plant scale," says Heidi Willing from fem.
