Process for Repairing a Component Comprising a Directional Microstructure by Setting a Temperature Gradient During the Laser Heat Action, and a Component Produced by Such a Process

• US 20100000976A1
• Filed: 07/22/2005
• Published: 01/07/2010
• Est. Priority Date: 07/22/2005
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Singer, Robert, Ott, Michael, Paul, Uwe, Volek, Andreas
• Granted Patent: US 8,141,769 B2
• Time in Patent Office: Days
• US Class Current: 219/121.17
• CPC Class Codes: B23K 1/0018 Brazing of turbine parts
• CPC Class Codes: B23K 1/002 Soldering by means of induction heating
• CPC Class Codes: B23K 1/0056 soldering by means of beams, e.g. lasers, E.B.
• CPC Class Codes: B23K 2101/001 Turbines
• CPC Class Codes: B23P 6/007 using only additive methods, e.g. build-up welding

Abstract

In one aspect, a repair method for repairing components comprising a base material with a directed microstructure is provided. The repair is performed in such a way that the repaired location correspondingly has a directed microstructure like the surrounding base material. A solder is applied in the region of a location to be repaired and is soldered to the component via heat exposure, a temperature gradient, i.e., for instance a temperature variation from a higher temperature to a lower temperature, is thereby produced in the region of the location to be repaired.

Claims

1-27. -27. (canceled)

28. A method for repairing a component having a base material with a directional microstructure, comprising:

applying a solder in a region of a location to be repaired, the solder comprises at least one constituent; and

applying heat at a soldering temperature so that the solder is soldered to the component,

wherein the soldering temperature of the solder is at least 30°

C. lower than a melting temperature of the base material,

wherein during applying heat, a temperature gradient in the region of the location to be repaired is set to generate a directional microstructure in the location to be repaired, and

wherein the repaired location has the same directional microstructure as the surrounding base material and that the applying heat takes place locally in the region of the location to be repaired.

29. The method as claimed in claim 28, wherein the difference between the soldering temperature of the solder and the melting temperature of the base material of the component is at least 50°

C.

30. The method as claimed in claim 28, wherein the difference between the soldering temperature of the solder and the melting temperature of the base material of the component is at least 70°

C.

31. The method as claimed in claim 28, wherein the difference between the soldering temperature of the solder and the melting temperature of the base material is 70°

C.±

4°

C.

32. The method as claimed in claim 28, wherein all the solder is completely applied prior to applying heat to completely melt the solder.

33. The method as claimed in claim 28, wherein the applying heat is effected by electron beams.

34. The method as claimed in claim 28, wherein the component comprises a nickel- or cobalt-base superalloy.

35. The method as claimed in claim 28, wherein the temperature gradient is oriented to extend in the direction of the orientation of the directional microstructure of the base material of the component.

36. The method as claimed in claim 28, wherein the first constituent has a melting temperature, which is lower than the melting temperature of the base material of the component,

wherein the solder includes a second constituent with a high durability and a melting temperature which is above the melting temperature of the first constituent but below the melting temperature of the base material up to the melting temperature of the base material, and

wherein the solder is applied in the region of the location to be soldered such that that the proportion of first constituent in the solder is higher in the vicinity of the base material than in a region further away from the base material.

37. The method as claimed in claim 28, wherein the temperature gradient is produced via a casting furnace for producing a casting with a directionally directed microstructure.

38. The method as claimed in claim 28, wherein a heat treatment of the base material is integrated into the soldering the solder.

39. The method as claimed in claim 28, wherein the solder consists of nano-powder.

40. The method as claimed in claim 28, wherein the solder is introduced onto or into the location to be repaired in the form of a paste, a slurry or a foil.

41. The method as claimed in claim 28, wherein the solder comprises just one constituent.

42. The method as claimed in claim 28, wherein the temperature gradient is determined by the soldering temperature of the solder and the temperature of the component, and wherein the temperature of the component is 300°

or room temperature.

43. The method as claimed in claim 28, wherein the location (3) that is to be repaired has a width of between 1 μ

m and 1000 μ

m.

46. The method as claimed in claim 33, wherein a laser power or a power of the electron beams is such that it at least partially melts the solder.

47. The method as claimed in claim 46, wherein the speed of travel or holding times of the laser beams or electron beams is such that the solder solidifies in dendritic form in the region of the location to be repaired.

44. The method as claimed in claimed 43, wherein the location to be repaired has a width of between 1 μ

m and 500 μ

m.

45. The method as claimed in claimed 43, wherein the location to be repaired has a width of between 400 μ

m and 600 μ

m in particular around 500μ

.