Method for repairing defects on hot parts of turbomachines through hybrid hot isostatic pressing (HIP) process

Patent metadata

Field	Value
Publication number	US-10760139-B2
Application number	US-201715797441-A
Country	US
Kind code	B2
Filing date	Oct 30, 2017
Priority date	Nov 18, 2016
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

In a hot isostatic pressing (HIP) method, the component to be treated, affected by imperfections, like porosity, cracks and cavities in its structure, is placed into a container together with non-metallic material in form of powder or grains having size greater than the porosity and the cracks and imperfections of the component. During the HIP process, the non-metallic material presses on the whole surface of the embedded component in order to generate a combination of temperature and forces capable to reduce defects, embedded and not embedded, in the component itself. The component is not contaminated during the process thus allowing easily removal of the non-metallic material by a simple operation of mechanical cleaning or chemical washing.

First claim

What is claimed is:

1. A hot isostatic pressing method for repairing a metal component having structural imperfections, the method comprising:
applying a first cleaning treatment to the component;
placing the component into a hermetic metal container;
introducing a non-metallic material medium into the container to completely embed the component;
outgassing the container through container apertures to remove gases and water vapor from within the container;
sealing the container apertures used to perform the outgassing;
placing the container inside a pressurized heating vessel of a hot isostatic pressing apparatus;
pressing and heating the container with predetermined pressure and temperature for a predetermined holding time interval;
extracting the component from the container; and
applying a second cleaning treatment to the component to remove the non-metallic medium.

2. The method according to claim 1 , wherein the predetermined pressure is applied through pressurized inert gas and ranges between 500 Bar (7250 Psi) and 3000 Bar (43500 Psi).

3. The method according to claim 1 , wherein the predetermined temperature ranges between 480° C. (896° F.) and 1300° C. (2400° F.).

4. The method according to claim 1 , wherein the predetermined holding time interval is greater than or equal to 2 hours.

5. The method according to claim 1 , wherein a metal chip selected from the group consisting of a sim, a plug, a patch fit, an insert and a tag is coupled to at least one of the structural imperfections of the component in order to reduce the minimum dimension of the larger structural imperfection of the component and therefore the dimensions of the medium.

6. The method according to claim 1 , wherein the predetermined pressure is greater than or equal to 1000 Bar (14500 Psi).

7. The method according to claim 1 , wherein predetermined temperature is greater than or equal to 1000° C. (1832° F.).

8. The method according to claim 1 , wherein the non-metallic material is a ceramic material in a powder or grain form selected from the group consisting of oxides, nitrides, carbides, carbonitrides, borides, and any mixture of oxides, nitrides, carbides, carbonitrides and borides.

9. The method according to claim 1 , wherein the non-metallic material is an oxide selected from the group consisting of alumina, magnesia, silica and zirconia.

10. The method according to claim 1 , wherein the non-metallic material is a nitride selected from the group consisting of TiN, silicon-nitrides and boron-nitrides.

11. The method according to claim 1 , wherein the non-metallic material is a carbide selected from the group consisting of TiC, WC, silicon-carbides and boron-carbides.

12. The method according to claim 1 , wherein the first cleaning treatment applied to the component is performed by chemical washing, by mechanical cleaning, by Hydrogen thermal cycle, or by Fluoride Ion Cleaning (FIC).

13. The method according to claim 1 , wherein the second cleaning treatment applied to the component is performed by chemical washing or by mechanical cleaning.

14. The method according to claim 1 , wherein the first cleaning treatment is performed by selective etching or mechanical disaggregation.

Assignees

• Nuovo Pignone Tecnologie Srl

Inventors

• Mola Paolo
• Masi Gabriele
• Branchetti Vincenzo
• Costantino Stefano

Classifications

• B22F3/15 Primary

  Hot isostatic pressing · CPC title

• B22F2201/20

  Use of vacuum · CPC title

• B22F2003/153

  apparatus specific to HIP · CPC title

• B22F2201/10

  Inert gases · CPC title

• B22F2302/20

  Nitride · CPC title