Method to improve the thermal properties of a resistance element embedded in an alumina deposit on a surface of a substrate and application of said method

Patent metadata

Field	Value
Publication number	US-9803499-B2
Application number	US-201314052909-A
Country	US
Kind code	B2
Filing date	Oct 14, 2013
Priority date	Oct 15, 2012
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A method for improving the heat resistance of a resistive element embedded in an alumina deposit covering a surface of a substrate, in which the alumina deposit includes a surface portion and a deep portion which is sandwiched between the surface portion and the surface of the substrate and in which the resistive element is located, is provided. The method includes a densification of the surface portion of the alumina deposit.

First claim

The invention claimed is:

1. A method for improving the heat resistance of a resistive element embedded in an alumina deposit covering a surface of a substrate, the alumina deposit comprising a surface portion and a deep portion which is sandwiched between the surface portion and the surface of the substrate and in which the resistive element is located, the method comprising:
densificating the surface portion of the alumina deposit, the densificating including
a) impregnating said surface portion by a solution comprising alumina particles and an aluminium phosphate;
b) drying the surface portion so impregnated; and
c) applying a heat treatment to the surface portion so dried.

2. A method according to claim 1 , wherein the solution used in a) is an aqueous solution which comprises 20% to 45% by mass of aluminium phosphate.

3. A method according to claim 1 , wherein b) is achieved at ambient temperature for a period of 1 hour to 4 hours.

4. A method according to claim 1 , wherein c) comprises in succession:
heating the surface portion of the alumina deposit to a temperature T 1 of between 90° C. and 100° C. for a period of 1 hour to 3 hours;
heating the surface portion of the alumina deposit to a temperature T 2 of between 240° C. and 280° C. for a period of 1 hour to 3 hours; and
heating the surface portion of the alumina deposit to a temperature T 3 of between 350° C. and 390° C. for a period of 1 hour to 3 hours.

5. A method according to claim 1 , wherein a thickness of the surface portion of the alumina deposit is between 20% and 30% of a total thickness of the alumina deposit.

6. A method according to claim 1 , wherein the resistance element is a strain gauge, and the substrate is a turbine blade.

Assignees

• Snecma

Inventors

• Gislard Vanessa Aurelie
• Ruelle Melanie Alice Camille

Classifications

• F01D5/288

  Protective coatings for blades · CPC title

• C04B2237/704

  of one or more of the ceramic layers or articles · CPC title

• F01D21/003 Primary

  Arrangements for testing or measuring (for measuring vibrations G01H) · CPC title

• C23C18/1208

  Oxides, e.g. ceramics · CPC title

• F05D2300/173

  Aluminium alloys, e.g. AlCuMgPb · CPC title