Advanced ceramics for gas turbines


© Fraunhofer IKTS
Silicon nitride radial turbine rotor for a micro gas turbine.
© Fraunhofer IKTS
Simulated temperature distribution (top) and stress distribution (bottom) of the turbine rotor.

In addition to various electrical applications, advanced ceramics are mainly used in gas turbines as thermal insulation. In aircraft engines and stationary gas turbines, they are used in the form of tiles or coatings on metallic components and thus enable the fuel gas temperature to be raised or cooling to be reduced. Both lead to an increase in efficiency and thus to a reduction in fuel consumption and pollutant emissions.

The efficiency of engines and gas turbines can be increased even further with all-ceramic components. Silicon nitride is particularly suitable for this purpose. Si3N4 has outstanding thermomechanical properties – even at very high temperatures.

Services offered


  • Development of specifically adapted ceramic materials for high-temperature applications as well as for oxidative and corrosive atmospheres and media
  • Application-oriented characterization of materials and components
  • Mechanical testing from room temperature to high temperatures (1550 °C)
  • Oxidation test up to 1600 °C
  • Hot gas corrosion test up to 1450 °C under gas turbine-like conditions
  • Prototype development and tests under near-application conditions


Technical equipment


  • Hot gas corrosion test stand (up to 1450 °C, 100 m/s, steam-enriched atmosphere) for investigations under gas turbine-like conditions
  • Corrosion test stand for investigations up to 1200 °C under steam atmosphere according to ASTM C863-83
  • Materials testing for fiber composites such as circular ring test and single fiber push-out test
  • Laboratory for mechanical materials testing according to various testing standards
© Fraunhofer IKTS
Test stand for testing the hot gas stability of ceramic materials.
© Fraunhofer IKTS
Sample during operation of the corrosion test stand.

Applications / references


Rotor for micro gas turbines


Micro gas turbines are particularly suitable for decentralized and independent energy conversion. With a combined heat and power system, microturbines can provide usable heat in addition to electricity. In a Fraunhofer project, a radial turbine rotor made of silicon nitride was developed for a micro gas turbine with 30 kWel, which allows fuel gas temperatures of 1200 °C in continuous operation and thus increases the temperature level by approx. 400 K. The silicon nitride radial turbine rotor can be manufactured in large series using a cost-effective process.


Material parameters of silicon nitride for radial gas turbine rotor
Operating temperature 1200 °C
Fracture toughness 6,8 MPa·m½
Strength ~ 1000 MPa
Fatigue strength at 1400 °C ~ 500 MPa
Silicon nitride engine blade.
© Fraunhofer IKTS
Silicon nitride engine blade.

Turbine blades for a helicopter turbine


Engines are always manufactured in axial design, i.e. without deflection of the gas flow. In such turbines, the rotor is usually not a compact component but a ring with individually attached blades. Within the project “Life-Cycle Engineering for Turbomachinery” ceramic blades for the first turbine stage of a helicopter engine (Klimov GTD 350) were developed and manufactured. The target operating temperature of the material was 1400 °C.

Material parameters of silicon nitride for engine blade
Operating temperature 1400 °C
Fracture toughness 6,1 MPa·m1/2
Strength ~ 700 MPa
Fatigue strength at 1400 °C ~ 450 MPa