Rapid filling of recesses by means of welding and component with filled recess

Abstract

The invention relates to a method for filling a recess (4) in a substrate (10), in which at least two different deposition methods and at least two, in particular three, different materials are used.

Description

[0001] 2024PF00889

[0002] Rapid filling of depressions by means of welding and component with filled depression

[0003] The invention relates to a rapid filling of depressions in metallic components where a defect has been hollowed out and needs to be filled.

[0004] Very large turbine guide vanes made of nickel-based alloys tend to crack when the TBC (turbine base coating) chips off.

[0005] Due to the depth and width of these cracks, these defects must be excavated and filled over a large area.

[0006] An economical repair means that material can be added to the trough quickly.

[0007] Known processes include arc welding processes such as GB 2315697.

[0008] The use of PSP elements is also common; these can be manufactured in advance and fill the missing volume in one piece, as described for example in EP 2 713 007 Al.

[0009] CMT methods are known from DE 10 2017 218859 Al.

[0010] The object of the invention is therefore to demonstrate a method in which material can be added quickly and without cracking by welding.

[0011] The problem is solved by a method according to claim 1 and a repaired component according to claim 10.

[0012] The dependent claims list further advantageous measures which can be combined arbitrarily to achieve further advantages.

[0013] They show

[0014] Figure 1 shows a depression to be filled,

[0015] Figure 2 shows the different layers in a depression. 2024PF00889

[0016] The figures and description represent only an embodiment of the invention.

[0017] Due to the large volume required, processes such as GMT welding are suitable for the economical filling of the trough geometry.

[0018] To avoid cracking in the base material of a substrate of a component with a recess, powder deposition welding is preferably suitable, in particular laser beam deposition welding (LMD) with a powder mixture of filler material / solder and base material.

[0019] Cracks that occur during the welding process can be sealed by high-temperature brazing.

[0020] Figure 1 shows a section of a component 1 to be repaired.

[0021] The component 1 preferably has a metallic substrate 10, preferably based on a nickel-based superalloy, a base material .

[0022] In the description of the invention and in the claims, "base material" also means "base material of the same type", which means:

[0023] There is at least one more or less alloying element present.

[0024] or

[0025] A proportion of an alloying element differs by a maximum of 20%, in particular by a maximum of 10%, from the material of the substrate 10 of the component.

[0026] A defect was present on or originating from a surface 7, which formed so that a depression 4 is now present.

[0027] Surface 7 preferably represents a side surface, such as side surfaces of a platform of a turbine blade or an end face of a blade tip. 2024PF00889

[0028] Figure 2 shows the structure 5 or layer sequence 5 in the depression 4 .

[0029] Surface 7 was prepared by hollowing out the defective area over a large area.

[0030] For the first layer, a base layer 13, a powder deposition welding process, in particular a laser powder deposition welding (LMD), is used, in which preferably a mixture of a base material, preferably the substrate 10, and a solder material is used.

[0031] However, a similar base material used for turbine blades can also be used here. Examples include IN769, CMSX, Alloy 247, ... .

[0032] A solder has a melting temperature that is at least 20K lower, and in particular at least 30K lower, than that of the base material.

[0033] Preferably, significantly higher proportions, in particular at least 10%, in particular 20% higher proportions of a melting point reducer such as boron (B) or silicon (Si) are present in the solder compared to the base material for the solder material.

[0034] Equally preferably, the lowering of the melting point is achieved by a higher or lower proportion, i.e. by at least 10%, in particular by at least 20%, of at least one alloying element compared with the base material.

[0035] This process step and the special adaptation of the material create a crack-free base layer 13. Preferably, only one or two layers of welding material are applied, thus preferably achieving a base layer thickness of 300-400 µm. 2024PF00889

[0036] 4

[0037] The mixture contains between 70 wt. % and 30 wt. % base material and, accordingly, between 30 wt. % and 70 wt. % solder material.

[0038] Next, a large-volume and rapid application of a middle layer 16 in the trough 4 is carried out using material of a base material, in particular the base material of the substrate 10, by means of the “Gold Metal Transfer” (GMT) welding process, which has a high deposition rate.

[0039] Here, a wire is used, so that the resulting microstructure has significantly coarser grains compared to powder deposition welding, on average at least 10%, and in particular at least 20% coarser grains.

[0040] The thickness of the middle layer 16 is preferably 900pm ± 300pm, depending on the size of the trough 4.

[0041] Finally, a solder layer 19 is applied, consisting of a mixture of base material and solder material, preferably the same mixture of base material / solder material as for the base layer 13, by means of a welding process, such as powder cladding welding.

[0042] A mixing ratio of 1 : 1 is preferably used.

[0043] The thickness of the solder layer 19 is preferably 300-400 pm.

[0044] The entire component with the filled recess 4 is heat-treated and, if necessary, reworked at the filled recess 4. 2024PF00889

[0045] 5

[0046] Examples of materials used:

[0047] Substrate: IN759

[0048] Base layer: IN759 / Lot (Amdry) GMT: IN759

[0049] Solder layer: IN759 / Lot (Amdry)

[0050] Substrate: Alloy247

[0051] Base layer: IN759 / Lot (Amdry) GMT: Alloy245

[0052] Solder layer: IN759 / Lot (Amdry)

[0053] Substrate: Alloy247

[0054] Base layer: Alloy247 / Lot (Allergy) GMT: Alloy247

[0055] Solder layer: Alloy247 / Solder (Amdry)

Claims

2024PF00889 Patent claims 1. Procedure for filling a depression (4) in a substrate (10) in which at least two different application methods, in particular only two different application methods, in particular welding methods, are used. and at least two, especially a maximum of three various materials can be used for three layers ( 13, 16, 19).

2. Method according to claim 1, where first a powder deposition welding process, in particular a laser powder deposition welding process, is used for a base layer ( 13 ) in the trough ( 4 ).

3. Method according to claim 2, in which a mixture of a solder material and a base material is used as the material for the base layer ( 13 ).

4. Method according to claim 2 or 3, where the base layer ( 13) is produced with only 2 to 3 layers using powder deposition welding.

5. Method according to claim 2, 3 or 4, where the mixture contains a proportion of 70 wt. % to 30 wt. % base material and accordingly 30 wt. % to 70 wt. % solder material.

6. Method according to one or more of claims 1, 2, 3, 4 or 5, in which a CMT procedure is used, to fill the depression (4) above the base layer (13) with a medium layer (16) in a large volume, in particular to at least 50 vol%, 2024PF00889 especially at least 60% by volume.

7. Method according to claim 6, in which a base material is used for the middle layer ( 16).

8. Method according to claim 6 or 7, in which, as the third and final material for a solder layer ( 19), a solder material mixture is applied by a welding process, which is in particular different from the mixture for the base layer ( 13) .

9. Method according to claim 8, in which a heat treatment of the substrate ( 10) is carried out as soldering.

10. Repaired component, especially turbine blade, which has a filled depression (4) in a substrate (10), wherein the depression (4) is filled layer by layer with at least two, in particular three different materials in three layers (13, 16, 19), in particular produced by a method according to one or more of the preceding claims.

11. Repaired component according to claim 10, where the material in the trough (4) as the base layer (13) is a mixture of solder material and base material, then a base material and then as the last layer ( 19) a mixture of solder material and base material is present .

12. Repaired component or method according to one or more of the preceding claims 6 to 11, where the layer thickness of the middle layer ( 16) 900pm ±2024PF00889 300pm, depending on the size of the trough (4 ).

13. Repaired component or method according to one or more of the preceding claims 2 to 12, where the thickness of the base layer ( 13) is 300pm to 400pm .

14. Repaired component or method according to one or more of the preceding claims 8 to 13, where the thickness of the solder layer ( 19) is 300pm to 400pm .

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