Advanced ceramic thermal barrier coatings for aero engines
April 16, 2013
Thermal barrier coatings (TBCs) are essential in providing thermal insulation to protect the underlying superalloy parts in aero engines and also land-based gas turbine engine. At the same time they must be strain compliance to minimise thermal-expansion-mismatch stresses with the superalloy parts on heating and cooling, and must also reflect much of the radiant heat from the hot gas, preventing it from reaching the metal alloy.
Innovnano, a manufacturer of high performance ceramic powder based in Porto Salvo, Portugal, has developed a highly pure 4YSZ (4 mol% yttria stabilized zirconia) thermal barrier coating material which is said to have exceptional properties for withstanding extreme temperature variations found in turbine engines environments. The powder is produced by the company’s patented Emulsion Detonation Synthesis (EDS) process.
Due to its low thermal conductivity only a very thin TBC is necessary for impact using 4YSZ, thereby ensuring that the component weight of the rotating turbines is kept to a minimum, states the company. With a melting point of ~2700°C and hardness of 14 GPa, the company claims its 4YSZ powder with its fine nanostructure with uniform dispersion of mixed oxide components, to be the ideal topcoat thermal barrier.
“There has been a dramatic growth in the market for high performance materials within the aerospace community and other high performance settings,” said Joấo Calado, Innovnano’s Technical Director. “Recognising this, Innovnano has recently relocated to a purpose-built manufacturing facility with significantly increased production capacity, and with our advanced EDS technology we are able to provide the highest quality thermal barrier topcoat materials at the volumes that industry needs.”