Ln1-xSrxMg1-yMnyAl11-zTizO19 nano-ceramic thermal barrier coating material and preparation method thereof

Abstract

The present invention discloses a Ln1-xSrxMg1-yMnyAl11-zTizO19 nano-ceramic thermal barrier coating material and a preparation method thereof, belongs to the technical field of new materials, the material formula is Ln1-xSrxMg1-yMnyAl11-zTizO19 (x is greater than 0 and less than or equal to 0.5, y is greater than 0 and less than or equal to 0.5, and z is greater than 0 and less than or equal to 0.5), and Ln is one or a combination of any of La, Pr, Nd, Sm, Eu, Gd, Er and Yb. Citrate sol - gel process is used, the prepared ceramic material shows plate planar micromorphology, the average grain size is 74-85nm, compared with widely used 7-8wt% yttria-stabilized zirconia (YSZ), the material has low thermal conductivity and high thermal expansion coefficient, solves the problems of serious sintering phase change failure, alloy matrix thermal mismatch, serious high temperature heat radiation and the like of high temperature ceramic thermal barrier coating material in the prior art, the material can be designed into a thermal barrier coating material, and the use temperature range is from room temperature to 2023K.

Description

technical field [0001] The invention belongs to the technical field of inorganic non-metallic materials, and relates to ceramic materials for thermal barrier coatings, in particular to Ln 1-x Sr x Mg 1-y mn y Al 11-z Ti z o 19 Nano-ceramic thermal barrier coating material and preparation method. Background technique [0002] In order to meet the requirements of high thrust-to-weight ratio, high efficiency, low fuel consumption and long life development of modern aero-turbine engines, the inlet temperature of turbine engines continues to rise, which puts higher demands on the high-temperature resistance of aero-engine hot-end components such as rotor blades and guide vanes. requirements. At present, the maximum service temperature of the alloy is lower than 1373K, and the single cooling structure design makes the temperature reduction of the blade very limited. For aeroengines with a thrust-to-weight ratio higher than 10, there is still a temperature difference of >...

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Problems solved by technology

At present, the maximum service temperature of the alloy is lower than 1373K, and the single cooling structure design makes the temperature reduction of the blade very limited. For aeroengines with a thrust-to-weight ratio higher than 10, there is still a temperature difference of >200°C that needs to be overcome.

[0003]The use of thermal barrier coating technology to further increase the operating temperature of the engine has a history of nearly 70 years. At present, the most widely used thermal barrier coating material is 7-8wt% Yttria stabilized zirconia (YSZ) ceramic material, but the YSZ material undergoes tetragonal metastable phase (t') to tetragonal phase (t) transformation when the working temperature is higher than 1200°C, and tetragonal phase (t) to tetragonal phase (t) occurs during cooling. The volume change caused by the transformation of cubic phase (c) and monoclinic phase (m) leads to cracking and failure of the coating; in addition, YSZ material is easy to sinter (increase in thermal conductivity, increase in elastic modulus and decrease in fracture toughness), oxygen ion conduction The rate increase (the oxidation rate of the metal bonding layer is accelerated) and other issues can no longer meet the requirements of the high inlet temperature of the new generation of aero turbine engines

Pyrochlore zirconate Ln2Zr2O7 (Ln is a rare earth metal) has lower thermal conductivity than YSZ, room temperature to There is no phase transition between melting points, high thermal stability, low Young's modulus and anti-sintering, but Ln2Zr2O7The material's low fracture toughness and low thermal expansion coefficient (~9.1×10-6 / K) limit its wide application in superalloys

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