TREA

Thermal barrier coatings and processes for applying same

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Information

  • Patent Application
  • 20070231589
  • Publication Number
    20070231589
  • Date Filed
    April 04, 2006
    18 years ago
  • Date Published
    October 04, 2007
    16 years ago
Information
Abstract
A process for applying a coating upon an article includes the steps of applying upon at least one surface of an article a bond coat layer composed of a bond coat material and at least one metal selected from the group consisting of magnesium, calcium, strontium, silicon, rare earth metals, Group 3A of the Periodic Table of Elements and Group 4A of the Periodic Table of Elements; oxidizing the at least one metal to form at least one surface variation on an exposed surface of the bond coat layer and to form a thermally grown oxide layer upon the bond coat layer; and applying a thermal barrier coating layer upon said thermally grown oxide layer to produce a coated article.
Description

BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is a flowchart representing a process of the present invention;



FIG. 2A is a flowchart representing one embodiment of a step in the process of FIG. 1;



FIG. 2B is a flowchart representing another embodiment of the step;



FIG. 2C is a flowchart representing yet another embodiment of the step;



FIG. 3 is a representation of a portion of a coated article having an overlay-type bond coat of the present invention; and



FIG. 4 is a representation of a portion of another coated article having a modified pack-type bond coat of the present invention.


Claims
  • 1. A process for applying a coating upon an article, comprising: applying upon at least one surface of an article a bond coat layer comprising a bond coat material and at least one metal selected from the group consisting of magnesium, calcium, strontium, silicon, rare earth metals, Group 3A and Group 4A of the Periodic Table of Elements;
  • 2. The process of claim 1, wherein the oxidation step comprises oxidizing said at least one metal to form a plurality of oxidized particulate metal proximate to an exposed surface of said bond coat layer and oriented substantially horizontal to said at least one surface of said article.
  • 3. The process of claim 1, wherein the oxidation step comprises oxidizing said at least one metal to form a plurality of oxidized particulate metal proximate to an exposed surface of said bond coat layer and oriented substantially perpendicular to said at least one surface of said article.
  • 4. The process of claim 1, wherein the oxidation step comprises oxidizing said at least one metal at a pressure of about 0.010 to 0.020 torr.
  • 5. The process of claim 1, wherein the oxidation step comprises heat treating the bond coated article at about 1500° F. to 2150° F. for about 5 minutes to 4 hours to form an alumina based layer upon said bond coat layer before the thermal barrier coating is applied.
  • 6. The process of claim 1, wherein the step of applying said bond coat layer comprises the steps of: melting said bond coat material in a first crucible;melting said at least one metal in a second crucible;applying said bond coat material upon said at least one surface of said article; andapplying said at least one metal upon an exposed surface of said bond coat material.
  • 7. The process of claim 6, wherein the at least one metal is applied at a pressure of about 0.010 torr to 0.020 torr.
  • 8. The process of claim 1, wherein the step of applying said bond coat layer comprises utilizing a deposition process selected from the group consisting of diffusion processes, low pressure plasma-spray, air plasma-spray, sputtering, cathodic arc, electron beam physical vapor deposition, high velocity plasma spray techniques, combustion processes, wire spray techniques, laser beam cladding, electron beam cladding, and electroplating.
  • 9. The process of claim 1, wherein the step of applying said bond coat layer comprises the steps of: melting said bond coat material in a crucible comprising at least one metal;forming a molten mixture of said bond coat material and said at least one metal; anddepositing said molten mixture upon said at least one surface to form said bond coat layer.
  • 10. The process of claim 1, wherein the step of applying said bond coat layer comprises the steps of: melting said bond coat material in a crucible to form molten bond coat material;depositing said at least one metal into said molten bond coat material;forming a molten mixture of said bond coat material and said at least one metal; anddepositing said molten mixture upon said at least one surface to form said bond coat layer.
  • 11. The process of claim 1, wherein the step of applying the thermal barrier coating comprises utilizing a deposition process selected from group consisting of physical vapor deposition processes, thermal spray processes, sputtering processes, sol gel processes, and slurry processes.
  • 12. A bond coat composition, comprising: a bond coat material and at least one oxidized metal selected from the group consisting of magnesium, calcium, strontium, silicon, rare earth metals, Group 3A and Group 4A of the Periodic Table of Elements.
  • 13. The bond coat composition of claim 12, wherein said bond coat material comprises an optional noble metal and an MCrAlY material, wherein said M is a metal selected from the group consisting of nickel, cobalt, iron and mixtures thereof.
  • 14. The bond coat composition of claim 12, wherein said bond coat material comprises an optional noble metal and a material selected from the group consisting of aluminum, platinum, and mixtures thereof.
  • 15. The bond coat composition of claim 12, wherein said bond coat material comprises an optional noble metal and a material selected from the group consisting of aluminum, platinum and MCrAlY, wherein said M of said MCrAlY is a metal selected from the group consisting of nickel, cobalt, iron, and mixtures thereof.
  • 16. A coated article, comprising: a bond coat layer disposed upon at least one surface of said article;a thermally grown oxide layer disposed upon said bond coat layer; anda thermal barrier coating layer disposed upon said thermally grown oxide layer,wherein said bond coat layer comprises a bond coat material and at least one metal selected from the group consisting of magnesium, calcium, strontium, silicon, rare earth metals, Group 3A and Group 4A of the Periodic Table of Elements.
  • 17. The coated article of claim 16, wherein said at least one metal comprises a plurality of oxidized particulate metal oriented substantially horizontal to said at least one surface.
  • 18. The coated article of claim 16, wherein said at least one metal comprises a plurality of oxidized particulate metal oriented substantially perpendicular to said at least one surface.
  • 19. The coated article of claim 16, wherein said bond coat material comprises an optional noble metal and a material selected from the group consisting of aluminum, platinum and MCrAlY, wherein said M of said MCrAlY is a metal selected from the group consisting of nickel, cobalt, iron, and mixtures thereof.
  • 20. The coated article of claim 16, wherein said thermal barrier coating comprises at least one of: a stabilized zirconate; anda stabilized hafnate.
  • 21. The coated article of claim 16, wherein said article comprises a turbine engine component.