Thermal Barrier Coatings (TBC’s) are designed to reduce the movement of heat. In some instances, such as exhaust systems, you want to keep the heat within the part. In combustion chambers you want to use the heat generated by combustion to push down on the piston rather than bleed off into surrounding surfaces. Due to continued testing we are learning that simple thermal barrier action is not the only characteristic that is important. In fact certain TBC’s will move an engine into detonation. TBC coatings can be made from a variety of materials. Ceramics get the most attention, though there are other materials that are superior in specific applications. The proper choice is critical to the overall function of the coating.