Thermal Barrier
A range of coatings designed to enable components to work within elevated or reduced temperatures. Thermal Barriers are often used on materials that work in temperatures above their melting point. The coatings also protect against oxidation, spalling and other associated heat induced effects.
Application of Thermal Barrier Coating to the inside surface of land based gas turbine combustor. (Process - Plasma Spray Coating system - CoNiCrAlY. Zirconia)
Thermal Barrier Coatings (TBC's) are used to reduce the operating temperature of a metallic component which in turn leads to extended working life. High energy, reliability and longer maintenance intervals are demanded from today's TBC's to reduce surface temperatures in environments of over 14,000°C. Components suffering from oxidation at high temperatures can be protected by using MCrAlY materials. The 'M' factor (Ni,Co,Fe or a combination thereof) will depend on the requirements of the application. TBC's are then applied to the surface of this material providing excellent reliability and long life.
Thermal Barrier Features
Oxidation & Corrosion Resistance
Low Thermal Conductivity
Enhanced Erosion Resistance
Longer Duty Cycle & Increased Part Life
Reduction of substrate operating temperature - lower thermal & creep stresses
Protection against 'hot spots'
Enhanced operation temperature resulting in increased thermal efficiency
Reduction of Nox emissions
Reduction in cooling requirement
Improved efficiency and fuel economy
Typical Applications
Diesel Engines -Piston Crowns, Valves etc.
Land Based Turbines -Transistion Ducts, Vanes, Combustors etc.
Aero Engines -Discharge nozzle, combustors etc.
Processes
Typical Materials
Top Coat
Yttria Stabilised Zirconia
Ceria Stabilised Zirconia (CeSZ)
Magnesia stabilised Zirconia
Bond Coat