EP3057735A1

EP3057735A1 - Method for protecting a component, laser drilling method, and component

Info

Publication number: EP3057735A1
Application number: EP14815267.1A
Authority: EP
Inventors: Christopher Degel; Diana Felkel; Andrea Massa
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2014-01-08
Filing date: 2014-12-02
Publication date: 2016-08-24
Also published as: DE102014200114A1; WO2015104098A1; US20160325382A1

Abstract

The use of a water-based amino acid-containing liquid mixture allows the cavities of a hollow component (1) to be filled rapidly and with ease, while the internal structure (22) is adequately protected. Furthermore, the filling material can very easily be removed again following the laser drilling process.

Description

Method for protecting a component, method for

Laser drilling and component

The invention relates to a method for laser drilling, a corresponding protective method and a component in which a filling material is introduced into the hollow component.

High-temperature components, such as turbine blades, are internally cooled, with air or superheated steam escaping through film cooling holes to further protect the surface.

Therefore, through holes must be made in the hollow molded component. However, during drilling, the inner structures must not be damaged or damaged as much as possible when the laser beam hits the inside of the hollow component when it breaks through.

Often a material that is hard at room temperature is heated, fluidized and introduced under pressure into the cavity.

Then, the laser beams, in which case the material must be removed by a complex and long Ausbrennprozess. It is therefore an object of the invention to solve the above-mentioned problem.

The object is achieved by a method according to claims 1, 8 and a component according to claim 9.

In the dependent claims further advantageous measures are listed, which can be combined with each other in order to achieve further advantages. Show it:

1 shows schematically a laser drilling device with a

Component,

FIG. 2 shows a turbine blade,

Figure 3 is a list of superalloys.

The figures and the description represent only embodiments of the invention.

In FIG. 1, only as an exemplary hollow component 1, a detail of a turbine blade 120, 130 (FIG. 2) made of a nickel- or cobalt-based alloy, preferably according to FIG. 3, having a cavity 10 is shown.

By a wall 16 of the cavity 10 of the component 1, 120, 130 in the area 19 in particular a through hole 19 (hereinafter only exemplified) - dashed lines indicated - are generated.

This is preferably done by a laser 4 (or electron gun), whose rays, starting from the surface 7 material of the wall 16 ablate. When breakthrough into the cavity 10 of the hollow member 1, 120, 130, the inner structure 22 could be damaged in the cavity 10.

In order to prevent this, a mixture 13 is introduced into the cavity 10 at least in the region of the through-hole 19 to be produced. The mixture 13 has at least one water-based

amino acid-containing liquid mixture.

Polysaccharides, more particularly heteropolysaccharides, can preferably be added to the mixture 13.

The mixture 13 may preferably be added to a salt, in particular pyruvate. Further preferably, a sulfate can be added to the mixture 13.

The mixture 13 is then heated before processing in the component 1, 120, 130, preferably at 373K to 383K, in particular for 10min - 120min, most especially for 90min.

After processing, in particular laser drilling, the mixture 13 can be easily removed from the blade 120, 130. Possibly. a much shorter burnout in the burnout is still necessary.

The mixture 13 acts as a protection, so that in a laser process both the percussion and the trepanier method can be used in order to produce a high-quality bore 19 and to avoid "recast".

After making the holes 19, the mixture 13 can be easily removed. This can be assisted by shaking and / or shaking.

As well as meandering cavities 10 are easily accessible.

One application also consists in reopening holes in a component 1, 120, 130 when the component 1, 120, 130 is coated with through-holes already drilled and the cavity 10 is also protected.

The described invention realizes significant savings in the laser drilling process time and in the process preparation and post-processing. In addition, the quality of the holes increases, since both percussion and trepanier methods can be used.

The advantage here is that the interior can be completely filled by filling with the mixture and thus better protected. FIG. 2 shows a perspective view of a moving blade 120 or guide blade 130 of a turbomachine that extends along a longitudinal axis 121. The turbomachine may be a gas turbine of an aircraft or a power plant for power generation, a steam turbine or a compressor.

The blade 120, 130 has, along the longitudinal axis 121, a fastening area 400, an adjacent blade platform 403 and an airfoil 406 and a blade tip 415.

As a guide blade 130, the blade 130 may have another platform at its blade tip 415 (not shown).

In the mounting region 400, a blade root 183 is formed, which serves for attachment of the blades 120, 130 to a shaft or a disc (not shown).

The blade root 183 is designed, for example, as a hammer head. Other designs as Christmas tree or Schwalbenschwanzfuß are possible.

The blade 120, 130 has a leading edge 409 and a trailing edge 412 for a medium flowing past the airfoil 406.

In conventional blades 120, 130, for example, solid metallic materials, in particular superalloys, are used in all regions 400, 403, 406 of the blade 120, 130.

Such superalloys are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949.

The blade 120, 130 can be made by a casting process, also by directional solidification, by a forging process, by a milling process or combinations thereof. Workpieces with a monocrystalline structure or structures are used as components for machines which are exposed to high mechanical, thermal and / or chemical stresses during operation.

The production of such monocrystalline workpieces takes place e.g. by directed solidification from the melt. These are casting processes in which the liquid metallic alloy is transformed into a monocrystalline structure, i. to the single-crystal workpiece, or directionally solidified.

Here, dendritic crystals are aligned along the heat flow and form either a columnar grain structure (columnar, i.e., grains that run the full length of the workpiece and here, in common usage, are referred to as directionally solidified) or a monocrystalline structure, i. the whole workpiece consists of a single crystal. In these processes, one must avoid the transition to globulitic (polycrystalline) solidification, since non-directional growth necessarily involves transverse and longitudinal grain boundaries, which negate the good properties of the directionally solidified or monocrystalline component.

The term generally refers to directionally solidified microstructures, which means both single crystals that have no grain boundaries or at most small angle grain boundaries, and stem crystal structures that have probably longitudinal grain boundaries but no transverse grain boundaries. These second-mentioned crystalline structures are also known as directionally solidified structures.

Such methods are known from US Pat. No. 6,024,792 and EP 0 892 090 A1.

Likewise, the blades 120, 130 may have coatings against corrosion or oxidation, e.g. B. (MCrAlX; M is at least one element of the group iron (Fe), cobalt (Co),

Nickel (Ni), X is an active element and stands for yttrium (Y) and / or silicon and / or at least one element of the rare earths, or hafnium (Hf)). Such alloys are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1.

The density is preferably 95% of the theoretical

Density.

A protective aluminum oxide layer (TGO = thermal grown oxide layer) is formed on the MCrAlX layer (as an intermediate layer or as the outermost layer).

Preferably, the layer composition comprises Co-30Ni-28Cr-8A1-0, 6Y-0, 7Si or Co-28Ni-24Cr-10Al-0, 6Y. In addition to these cobalt-based protective coatings, nickel-based protective layers such as Ni-IOCr-12A1-0.6Y-3Re or Ni-12Co-21Cr-IIAl-O, 4Y-2Re or Ni-25Co-17Cr-10A1-0,4Y-1 are also preferably used , 5Re.

On the MCrAlX may still be present a thermal barrier coating, which is preferably the outermost layer, and consists for example of Zr0 ₂ , Y ₂ 0 ₃ -Zr0 ₂ , that is, it is not, partially or completely stabilized by yttria

and / or calcium oxide and / or magnesium oxide.

The thermal barrier coating covers the entire MCrAlX layer.

By suitable coating methods, e.g. Electron beam evaporation (EB-PVD) produces stalk-shaped grains in the thermal barrier coating.

Other coating methods are conceivable, e.g. atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may have porous, micro- or macro-cracked grains for better thermal shock resistance. The thermal barrier coating is therefore preferably more porous than the

MCrAlX layer.

Refurbishment means that components 120, 130 may have to be freed of protective layers after use (eg by sandblasting). This is followed by removal of the corrosion and / or oxidation layers or products. Optionally, even cracks in the component 120, 130 are repaired. Thereafter, a the coating of the component 120, 130 and a renewed use of the component 120, 130.

The blade 120, 130 may be hollow or solid. If the blade 120, 130 is to be cooled, it is hollow and may still film cooling holes 418 (indicated by dashed lines) on.

Claims

claims

1. A method for protecting a component (1, 120, 130) during laser machining or melt-phase machining,

especially when laser drilling,

the component (1, 120, 130) having a cavity (10), in particular in which a through hole (19) is introduced through a wall (16) of the cavity (10) of the component (1, 120, 130),

in which the cavity (10) is filled at least in the region of the region (19) to be processed,

characterized in that

as filling a mixture (13) of a water-based amino acid-containing liquid mixture in the cavity (10) is introduced.

2. The method according to claim 1,

in the polysaccharides,

in particular heteropolysaccharides,

be added to the mixture (13),

and be introduced.

3. The method according to one or both of claims 1 or 2, wherein a salt,

especially pyruvate,

is added to the mixture (13),

and is introduced.

4. The method according to one or more of claims 1 to 3,

in which a sulfate is added to the mixture (13) and introduced. Method according to one or more of claims 1 to

4,

in which the entire cavity (10) is filled with the mixture (13).

Method according to one or more of claims 1 to

5,

in which the mixture (13) before processing at 373K to

383K is heated,

especially for 10min - 120min,

especially for 90min.

Method according to one or more of the preceding claims,

in which a very short burnout process occurs after the introduction of the through holes (19) to remove the material from the cavity (10).

A method of laser drilling a component (1, 120, 130) having a through-hole (19) introduced through a wall (16) of the cavity (10) of the component (1, 120, 130) and a method of protecting the cavity (10) according to one or more of claims 1 to 7 is used.

Hollow component (1, 120, 130) with mixture (13) according to one or more of claims 1, 2, 3, 4, 5 or 6,

in the cavity (10).