High-entropy oxides for thermal barrier coating (TBC) top coats

Abstract

A thermal barrier coating (TBC) top coat which is a high entropy oxide (HEO) having a high configurational entropy, contains at least 5 different oxide-forming metallic cations, is a single phase or single crystalline structure, such as tetragonal or cubic over unexpectedly wide temperature ranges up to and beyond top coat operating temperatures of preferably at least 2300 DEG F. The TBC top coats exhibit low thermal conductivity, good sintering resistance, excellent phase stability and good thermal cycling performance. At least five of the different oxide-forming metallic cations include: a) at least one of the transition metals: Sc, Y, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Ni, Cu, or Zn, and / or at least one of the lanthanides La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb. Dy, Ho, Er, Yb, or Lu. One of the at least five different oxide-forming metallic cations may also comprise at least one of the alkaline-earth metals: Be, Mg, Ca, Sr, or Ba.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 743,392, filed October 9, 2018, the disclosure of which is expressly incorporated herein by reference in its entirety. technical field [0003] The present invention relates to topcoat materials for thermal barrier coatings (TBC), which have excellent phase stability and dimensional stability over a wide temperature range, as well as good thermal cycle performance and low thermal conductivity. Topcoat materials can be in the form of powders, alloys, topcoats or coating layers, and can be applied in thermal spray powder form with bond coat materials to obtain thermal barrier coating (TBC) systems. The present invention also relates to a method for reducing delamination of a topcoat from a bond coat and a substrate, such as a gas turbine engine component. Background technique [0004] A complete thermal barrier coating system includes a to...

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