Developing self-healing gas turbines

The to-be created self-healing coating should replace the thermal barrier coatings (TBC) that are being used at the moment. “Because of the TBC it is possible to have extremely high temperatures, beyond the melting point of structural components, inside a gas turbine. It protects the most critical parts of, for example, a jet engine”, says Dr. ir. Wim Sloof (Mechanical, Maritime and Materials Engineering Faculty). “This will save fuel and money and reduces CO2-emissions. But the difference between high temperatures during the flight and the coldness when the engine is not operating, creates cracks in the coating.”

The new self-healing material will repair these cracks during service, the researchers think. Gas turbines are used in airplanes, power stations, submarines and ships. TU Delft will lead the European Union project SAMBA to create the new material. It received a 3.2 million euro subsidy. In SAMBA, industry and universities work together. “The aim of the project is that we’ll develop a coating that could be used by the industry after four years. We hope to extend the lifetime with 25% and reduce the maintenance costs”, says Sloof.

 

next level

next level

next level

TU Delft has been working on creating self-healing coatings for years. “We’re taking the development to the next level,” says Sloof. “We have tested coatings in laboratories and gotten a very good understanding of the process of self-healing. Now we’re going to optimize the coating to make it work well. And see if it can repair starting cracks significantly.”

The consortium has developed a step-by-step schedule. “We will first create the new self-healing material,” explains Sloof. “At the German Forschungszentrum Jülich we will see how well it works. They are specialized in experimenting with high-temperature materials. After that, the self-healing material will be tested in Sweden. Gas turbine builder GKN Aerospace has a test facility where the new coating can be applied to a real turbine engine component.”

It is very important to work together with the industry, stresses Sloof. “They should be able to use the coating we’re developing. I’m optimistic that this will happen, because we cooperate with important gas turbine and coating companies that cover a big part of the market.”