Thermal Barrier Coating (TBC)
Definition - What does Thermal Barrier Coating (TBC) mean?
A thermal barrier coating (TBC) is a highly advanced system applied to surfaces, like metals, especially in aviation engine and gas turbine parts that operate at extremely high temperatures. It performs well in managing exhaust heat.
Corrosionpedia explains Thermal Barrier Coating (TBC)
TBCs contain four main layers:
- Metallic bond coat
- Metal substrate
- Ceramic top coat
- Oxide grown thermally
Typically, the ceramic top coat is composed of yttria stabilized zirconia (YSZ), which is known for its low conductivity and stability under nominal temperatures for operation. Alternatives to YSZ have been created, but ceramic top coats with YSZ are relatively tougher and can deliver better performance.
Thermal barrier coatings can be used in various industrial and automotive settings. For instance, TBCs can be used to lessen heat loss from the exhaust system of automobile engines which may include:
- Exhaust manifolds
- Other components
Such coatings can serve as insulators, especially in components that are often exposed to prolonged heating. This type of coating can accommodate higher temperatures during operation and at the same time, limit thermal exposure of other structures. It can prolong the life of parts and other structures by decreasing thermal fatigue and oxidation.
Though this type of coating can be applied straight to metal parts, advanced technology allows TBC application on composite materials. Due to this, TBC coating is often used in high-performance vehicles like Formula 1. Apart from providing thermal protection, it can be used in preventing degradation due to friction.
The role of TBC is to prevent melting, promoting high gas temperature inlets, which leads to more efficient energy conversion. While this is the case, the surface must be prepared thoroughly before coating with TBC to achieve the best results.