Laser assisted oxide removal

Patent metadata

Field	Value
Publication number	US-9683281-B2
Application number	US-201514683820-A
Country	US
Kind code	B2
Filing date	Apr 10, 2015
Priority date	Apr 10, 2015
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

A method of forming a thermal barrier coating on a metal part includes laser cleaning a surface of the metal part to remove undesirable oxides and residues from the surface of the part. It further includes depositing an aluminum containing bondcoat on the part and thermally interdiffusing the bondcoat and the part with a heat treatment. Laser cleaning a surface of the bondcoat to remove oxides and debris from the surface forms an alpha aluminum oxide layer on the bondcoat. A ceramic topcoat is then deposited on the alpha aluminum oxide layer at a temperature above 1800° F. (982° C.).

First claim

The invention claimed is:

1. A method of forming a thermal barrier coating on a metal part comprising:
laser cleaning a surface of the metal part to remove undesirable oxides and residues from the surface of the part;
depositing an aluminum containing bondcoat on the part;
thermally interdiffusing the aluminum containing bondcoat and the part with a heat treatment;
laser cleaning a surface of the aluminum containing bondcoat to remove oxides and debris from the surface of the bondcoat and form an alpha aluminum oxide layer on the bondcoat;
preheating the surface of the aluminum containing bondcoat above 1800° F. (982° C.); and
depositing a ceramic topcoat on the alpha aluminum oxide layer on the bondcoat.

2. The method of claim 1 wherein the metal part comprises a nickel based, cobalt based, iron based superalloy or mixtures thereof.

3. The method of claim 1 wherein laser cleaning comprises exposing the surface to a laser focused on the surface of the metal part or on the surface of the aluminum containing bondcoat.

4. The method of claim 3 wherein the laser comprises a YAG (yttrium aluminum garnet), UV (ultraviolet), eximer, CO 2 (carbon dioxide), fiber, or disc laser.

5. The method of claim 1 wherien the aluminum containing bondcoat comprises MCrAlY wherein M is Ni, Co, Fe, Pt, Hf, Si, Fe-base, Ni-base, or Co-base alloys, or mixtures thereof.

6. The method of claim 1 wherein depositing the aluminum containing bondcoat comprises low pressure plasma spray (LPPS), high velocity oxy fuel (HVOF) spray, cathodic arc deposition, or chemical vapor deposition.

7. The method of claim 6 wherein depositing the ceramic topcoat comprises electron beam physical vapor deposition (EBPVD).

8. The method of claim 1 wherein the ceramic topcoat comprises yttria stabilized zirconia, gadolinia zirconia, ceria stabilized zirconia, or mixtures thereof.

Assignees

• United Technologies Corp

Inventors

• Meehan Robert J
• Ridgeway Neil B
• Millea Christopher J

Classifications

• C23C28/3455

  with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer · CPC title

• B23K26/123

  in an atmosphere of particular gases · CPC title

• B23K2103/10

  Aluminium or alloys thereof · CPC title

• C23C14/022

  by means of bombardment with energetic particles or radiation · CPC title

• B23K26/122

  in a liquid, e.g. underwater · CPC title