Part comprising a substrate and an environmental barrier

• US 11,713,283 B2
• Filed: 01/04/2018
• Issued: 08/01/2023
• Est. Priority Date: 01/06/2017
• Status: Active Grant

• Current Assignee: Centre National De La Recherche Scientifique, Safran Ceramics, Université de Bordeaux
• Original Assignee: Safran Ceramics
• Inventors: Pin, Lisa, Arnal, Simon, Rebillat, Francis, Mauvy, Fabrice
• Primary Examiner(s): Sample, David
• Application Number:
  US16/475,903
• Publication Number:
  US 20190330121A1
• Time in Patent Office: 2,035 Days
• CPC Class Codes: C04B 2103/0021 Compounds of elements having a valency of 3
• CPC Class Codes: C04B 35/565 based on silicon carbide
• CPC Class Codes: C04B 35/584 based on silicon nitride
• CPC Class Codes: C04B 35/806 The matrix of the ceramic products consisting of non-oxides only
• CPC Class Codes: C04B 41/0009 Demolition agents based on cementitous or like materials
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4527 Plasma spraying deposition from the gas phase using plasma C04B41/4533
• CPC Class Codes: C04B 41/5024 Silicates C04B41/5022 takes precedence; silico-fluorides C04B41/5018
• CPC Class Codes: C04B 41/5045 Rare-earth oxides
• CPC Class Codes: C04B 41/52 Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
• CPC Class Codes: C04B 41/526 Multiple coating or impregnation with materials having the same composition but different characteristics
• CPC Class Codes: C04B 41/87 Ceramics
• CPC Class Codes: C04B 41/89 for obtaining at least two superposed coatings having different compositions
• CPC Class Codes: F01D 5/284 Selection of ceramic materials
• CPC Class Codes: F01D 5/288 Protective coatings for blades

Abstract

A part includes a substrate, having, adjacent to a surface of the substrate, at least a portion that is made from a material that contains silicon, and an environmental barrier formed on the surface of the substrate, the environmental barrier including at least a first layer including a rare earth disilicate of formula RE^a₂Si₂O₇ present at a molar content lying in the range 70% to 99.9%, where RE^a is a rare earth element; and at least one rare earth oxide of formula RE^b₂O₃ present at a molar content lying in the range 0.1% to 30%, where RE^b is a rare earth element different from RE^a.

Claims

1. A part comprising a substrate, having, adjacent to a surface of the substrate, at least a portion that is made from a material that contains silicon, and an environmental barrier formed on the surface of the substrate, the environmental barrier comprising at least a first layer comprising:

a rare earth disilicate of formula RE^a₂Si₂O₇ present at a molar content lying in the range 85% to 95%, where RE^a is a rare earth element, wherein RE^a is selected from yttrium Y and ytterbium Yb; and

at least one rare earth oxide of formula RE^b₂O₃ present at a molar content lying in the range 5% to 15%, where RE^b is a rare earth element different from RE^a, wherein RE^b is selected from terbium Tb, erbium Er, dysprosium Dy and lutetium Lu,

wherein the environmental barrier further comprises a second layer present on the first layer, the second layer comprising at least;

one rare earth monosilicate of formula RE^c₂SiO₅, where RE^c is a rare earth element at a molar content lying in the range 85% to 99.9%; and

at least one rare earth oxide of formula RE^d₂O₃ present at a molar content lying in the range 0.1% to 15%, where RE^d is a rare earth element different from RE^c.

2. A part according to claim 1, wherein RE^d is selected from terbium Tb, erbium Er, dysprosium Dy, gadolinium Gd, europium Eu, lutetium Lu, samarium Sm, yttrium Y, and ytterbium Yb.

3. A part according to claim 2, wherein RE^d is selected from terbium Tb, erbium Er, and dysprosium Dy.

4. A part according to claim 1, wherein the rare earth monosilicate of formula RE^c₂SiO₅ is present in the second layer at a molar content lying in the range 85% to 95%, and wherein said at least one rare earth oxide of formula RE^d₂O₃ is present in the second layer at a molar content lying in the range 5% to 15%.

5. A part according to claim 1, wherein RE^c is selected from yttrium Y and ytterbium Yb.

6. A part according to claim 1, wherein RE^a is yttrium Y, RE^c is ytterbium Yb, and RE^d is selected from terbium Tb, erbium Er, and dysprosium Dy.

7. A part according to claim 1, wherein the environmental barrier further comprises a third layer present between the first layer and the second layer, the third layer comprising:

the rare earth disilicate of formula RE^a₂Si₂O₇ at a molar content equal to A·

Ta, where Ta is the molar content of RE^a₂Si₂O₇ in the first layer;

said at least one rare earth oxide of formula RE^b₂O₃ at a molar content equal to A·

Tb, where Tb is the molar content of RE^b₂O₃ in the first layer; and

the rare earth monosilicate of formula RE^c₂SiO₅ at a molar content equal to (1−

A)·

Tc, where Tc is the molar content of RE^c₂SiO₅ in the second layer;

where A designates a weighting coefficient that is strictly greater than 0 and strictly less than 1.

8. A method of fabricating a part according to claim 1, comprising forming the first layer of the environmental barrier on the surface of the substrate.

9. A method of using a part according to claim 1, comprising using said part at a temperature higher than or equal to 800°

C. in a medium that is oxidizing and wet.

10. A part according to claim 7, wherein the molar content of RE^d₂O₃ in the second layer is less than the molar content of RE^b₂O₃ in the first layer.

11. A part according to claim 1, wherein RP is yttrium Y.

12. A part according to claim 1, wherein the at least one rare earth oxide of formula RE^b₂O₃ is present at a molar content lying in the range 5% to 10%.

13. A part comprising a substrate, having, adjacent to a surface of the substrate, at least a portion that is made from a material that contains silicon, and an environmental barrier formed on the surface of the substrate, the environmental barrier comprising at least a first layer comprising:

a rare earth disilicate of formula RE^a₂Si₂O₇ present at a molar content lying in the range 85% to 95%, where RP is a rare earth element, wherein RE^a is selected from yttrium Y and ytterbium Yb; and

at least one rare earth oxide of formula RE^b₂O₃ present at a molar content lying in the range 5% to 15%, where RE^b is a rare earth element different from RE^a, wherein RE^b is erbium Er.

14. A part according to claim 13, wherein RE^a is yttrium Y.