The global volume of traffic is constantly increasing, and emissions of carbon dioxide and nitrogen oxides continue to rise. This also applies to aviation: by 2036, the number of active commercial aircraft worldwide is expected to almost double to 45,000. The number of passenger kilometres flown is also expected to double to more than 17 billion per year. In view of these figures, the EU wants to reduce emissions and noise caused by aviation. This is to be achieved through the use of intelligent flight plans, alternative fuels and, in particular, efficient propulsion systems.
New engines must be more efficient
This poses a challenge for manufacturers of aircraft engines: How can the engines be designed in such a way that they convert the energy of the fuel better into thrust? The key to this lies in a higher combustion temperature, which leads to a better efficiency of the engine. In a consortium led by engine manufacturer MTU Aero Engines, the Schunk Group is researching how and from which materials the engines of the future will have to be constructed in order to enable higher combustion temperatures. The project is publicly funded: Chancellery Minister Prof. Dr. Helge Braun took this opportunity to inform himself about the state of development on site in Heuchelheim. As head of the Chancellery, Braun is one of the most important politicians at the federal level in Germany and one of Chancellor Angela Merkel's closest collaborators.
High-tech materials are the key
"Today's aircraft engines are reaching their limits with rising combustion temperatures because the metallic materials used would simply not be able to withstand the necessary temperatures," explains Dr.-Ing. Florian Reichert, Head of Development for Composite Materials at Schunk. This is where Schunk's expertise in the high-tech materials carbon and ceramics comes into play, where the technology group is a global leader. Dr.-Ing. Reichert and his team are working on fiber-reinforced composites based on carbon and ceramics. "The solution lies in components manufactured from so-called CMC - Ceramic Matrix Composites," explains Dr.-Ing. Reichert.
Long experience and highly specialized production
In order to produce such ceramic fibre composites, fibres made of the extremely temperature-resistant material silicon carbide are coated and subsequently laminated. At high temperatures, infiltration with molten silicon takes place - an elaborate and technically complex manufacturing process that requires a great deal of experience and appropriate machinery. "Here we benefit from our decades of experience with fibre composite materials and our highly specialized production," says Dr.-Ing. Reichert. Products manufactured in this way, such as moving parts from the combustion chamber of an aircraft engine, can withstand much higher temperatures than metal components. As a result, combustion temperatures can be increased, engine efficiency improved and emissions reduced. "The engine gets more out of the same amount of fuel," Dr.-Ing. Reichert sums it up. In addition, ceramic fiber composite components save two thirds of the weight of metallic components. This would help to make aircraft lighter, which would also save energy, Reichert said.
Schunk Group is long-term oriented
"The aircraft industry reckons in long periods of time, the new generation of engines will probably come into service in ten years at the earliest and then be in operation for many years," explained Dr. Arno Roth, CEO of the Schunk Group. Since Schunk, as a foundation company, has a long-term orientation, the technology group can also tackle such very long-term projects without having to keep an eye on quick profits, Dr. Roth continued. "However, we are very grateful for the support provided by public research funding. This is because it enables Schunk to develop economically viable innovations that contribute to strengthening Germany as an industrial location and ultimately generate economic returns."
"Materials research is key technology."
"Materials research is one of the decisive key technologies when it comes to Germany's future competitiveness and innovative ability," said Chancellery Minister Helge Braun at the presentation of the project in Heuchelheim. "It is the driving force behind many innovations in almost all areas of technology and life. Because without innovative materials there are no new products." Due to its great importance, the German government is investing around 100 million euros per year in materials research and materials technology as part of the new high-tech strategy, Braun explained, reiterating: "With its expertise in materials and manufacturing competence, the Schunk Group is an indispensable research and development partner for this program.
