Thermal-insulating coating with low thermal conductivity

Abstract

A ceramic material having particular utility as a thermal insulating or thermal barrier coating on metallic substrates is provided. The ceramic material broadly comprises at least one lanthanide sesquioxide and the balance comprising a first oxide selected from the group consisting of zirconia, ceria, and hafnia. The lanthanide sesquioxide has a formula A2O3 where A is selected from the group consisting of La, Pr, Nd, Sm, Eu, Tb, In, Sc, Y, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof. The present invention also broadly relates to an article having a metal substrate and a thermal barrier coating as discussed above.

Description

technical field

[0001] The invention relates to a heat-insulating coating made of a ceramic material and to a metal part provided with such a heat-insulating coating. Such insulating coatings are particularly suitable for use on gas turbine engines. Background technique

[0002] Gas turbine engines are very well developed mechanical devices that convert chemical potential energy in the form of fuel into thermal energy and then into mechanical energy for propelling aircraft, generating electricity, pumping fluids, etc. At present, the main feasible way to improve the efficiency of gas turbine engines appears to be to use higher operating temperatures. However, metallic materials currently used in gas turbine engines are very close to the upper limit of their thermal stability. In the hottest parts of modern gas turbine engines, metallic materials are used at gas temperatures above their melting points. They are maintained thanks to air cooling. How...