Gas Turbine Thermal Barrier Coating

Mecanismos de falla y principales características microestructurales julian d.

Gas turbine thermal barrier coating.

Nonetheless thermal barrier coatings tbcs made of low thermal conductivity ceramics are now being used to provide thermal insulation to metallic components from the hot gas stream in gas turbine engines used for aircraft propulsion power generation and marine propulsion. Tbcs which comprise metal and ceramic multilayers insulate turbine and combustor engine components from the hot gas stream and improve the durability. Thermal spray coatings for industrial gas turbines produce substantial benefits. Of all these thermal barrier coatings tbcs have the most complex structure and must operate in the most demanding high temperature environment of aircraft and industrial gas turbine engines.

Universidad nacional de colombia medellín colombia jdosorio unal edu co. Thermal barrier coatings tbcs are advanced materials systems usually applied to metallic surfaces operating at elevated temperatures such as gas turbine or aero engine parts as a form of exhaust heat management these 100 μm to 2 mm thick coatings of thermally insulating materials serve to insulate components from large and prolonged heat loads and can sustain an appreciable temperature. The thickness of the zirconia required depends upon the gas stream temperature and the amount of cooling available. These are ceramic coatings with very low thermal conductivity.

The gas path of these parts are coated with a thermal barrier coating typically consisting of a metallic layer called the bond coat made of a material referred to as an mcraly an alloy of metals like nickel or cobalt or some combination thereof and. Coatings for combustion liners are normally specified by the turbine manufacturer. The use of tbcs 100 to 500 μm in thickness along with internal. Thermal barrier coatings tbcs are widely used in some components of the commercial gas turbine engines including the combustion chambers the nozzles and the blades to control the high heat flux entering from the combustion gas to the structural components.

Functionally graded materials 1996 1997. Thermal barrier coatings tbcs are widely used in hot sections of gas turbine engines to improve their operating temperature and provide thermal protection for the underlying metallic components thereby improving the efficiency and performance of the engine. These coatings can be applied to a thickness of 2 mm although typical thickness is in the range of 0 2 mm to 0 5 mm. Despite being typically 1 5 mm thin the allow for a drop of 100 300 o c between the gas and metal surface temperatures.

A second type of coatings applied to high temperature parts are known as thermal barrier coatings tbc.