Thermal Barrier Coatings (TBC)
One of the most common uses of Thermal barrier coatings TBC’s is in the combustion sections of aircraft turbine engines. With the demand for fuel economy and increased power, combustion temperatures are approaching the design limits of the metal alloys from which turbine components are made. The use of thermal barrier coatings in this and other application enables the use of the alloys at higher temperatures, by reducing the temperature to which the parts are exposed. With the ability of thermal spray to apply an almost limitless number of materials, well-engineered thermal barrier coatings can be produced to solve even some of the most complex thermal barrier problems.
When engineering a thermal barrier coatings system, Thermal Spray Technologies uses its strong expertise in materials engineering and its strength of understanding of the processes of thermal spray. The combination of this knowledge provides application specific solutions to our customers’ thermal management problems.
Coating Materials
The most commonly used thermal spray TBC materials for turbine engines are oxide ceramics, specifically yttria-stabilized zirconia (YSZ). However, other materials can and have been used for thermal barrier coatings, even metal alloys. Materials that have been used for thermal management include YSZ, alumina compounds, refractory metals, and stainless steels. Because every thermal management problem is unique, consultation with TST’s materials engineering staff is recommended.
Substrate Materials
There are few, if any, limitations to the substrate materials. Typically, thermal barrier coatings are applied to metallic substrates, however, composite structures can also be coated. Where the application involves high temperatures, gradated coatings are employed to mitigate differential expansion between the substrate and the thermal barrier coatings.
Examples
Practical uses for thermal barrier coatings include turbine blades, burner cans, and aft liners for turbine engines to increase fuel efficiency and power. Thermal barrier coatings have been used in racing engines since the 70’s. Automotive and heavy equipment pistons and missile components are also coated with thermal barrier coatings. Thermal barrier coatings are also use in braking systems to keep heat away from hydraulic components.
Jet engines with various components coated with Thermal Barrier Coatings