METHOD FOR FORMING A DEFINED SURFACE ROUGHNESS IN A REGION OF A COMPONENT FOR A TURBOMACHINE, WHICH COMPONENT IS TO BE MANUFACTURED OR IS MANUFACTURED ADDITIVELY

Abstract

A method for forming a defined surface roughness in a region of a component that is to be manufactured or is manufactured additively includes setting an irradiation parameter and/or an irradiation pattern in such a way that a component material is provided with a certain porosity in the region under a surface of the component, which porosity is suitable for causing the defined surface roughness in the component. A corresponding component is also specified.

Claims

1.-12. (canceled)

13. A method for forming a defined surface roughness in a region of a component which is to be produced or is produced additively, comprising: setting of an irradiation parameter and/or an irradiation pattern in such a way that a component material in the region below a surface of the component is provided with a defined porosity; wherein, to form the defined surface roughness in the region, setting an irradiation power or a laser power in accordance with an expected surface roughness, and/or setting a scanning speed is set in accordance with an expected surface roughness.

14. The method as claimed in claim 13, wherein the component material is provided with the defined porosity in a depth of less than 500 m below the surface.

15. The method as claimed in claim 13, wherein the component material is provided with the defined porosity in a depth between 5 and 15 layer thicknesses below the surface.

16. The method as claimed in claim 15, wherein, to form the defined surface roughness in the region, a high irradiation power, and a low scanning speed is set.

17. The method as claimed in claim 13, wherein, to form the defined surface roughness in the region, a low irradiation power, and a high scanning speed is set.

18. The method as claimed in claim 13, wherein, to form the defined surface roughness in the region, a spacing of 50 to 500 m is provided between a surface irradiation vector and a contour irradiation vector.

19. The method as claimed in claim 13, wherein, to form the defined surface roughness in the region, surface irradiation vectors extending perpendicularly to a layer contour and having a length of less than 500 m are provided.

20. The method as claimed in claim 13, wherein the defined porosity is formed in such a way that it detectable by means of a radiographic examination.

21. The method as claimed in claim 13, wherein the region represents an identification region, which is automatically analyzed by an identification unit to identify the component.

22. The method as claimed in claim 13, wherein the irradiation parameter and/or the irradiation pattern are set randomly by a computer, to provide the component with a random pore pattern.

23. A component which is provided in the region with the defined surface roughness according to the method as claimed in claim 13.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Further details of the invention are described hereinafter on the basis of the figures.

[0049] FIG. 1 shows a schematic sectional or side view of an additively produced component.

[0050] FIG. 2 shows a simplified schematic sectional or side view of the additively produced component.

[0051] FIG. 3 schematically indicates an irradiation pattern for or during the additive production of the component.

DETAILED DESCRIPTION OF INVENTION

[0052] In the exemplary embodiments and figures, identical or identically-acting elements can each be provided with identical reference signs. The illustrated elements and the size ratios thereof to one another are fundamentally not to scale, but rather individual elements can be shown exaggeratedly thick or large-dimensioned for better illustration capability and/or for better comprehension.

[0053] FIG. 1 shows a component 10 in a schematic sectional view. The component 10 is shown in particular during its additive production on a construction panel 14. The corresponding production method is advantageously selective laser melting or electron beam melting. Alternatively, it can be a selective laser sintering method.

[0054] The component 10 is advantageously produced layer by layer by selective solidification of layers of a component material (not explicitly identified). The solidification is advantageously performed by an energy beam 2, originating from an irradiation unit 3, advantageously a laser beam source, having a corresponding scanning or guiding optical unit (not explicitly identified). The component comprises a surface OF. The surface OF can comprise, for example, a lateral surface of the component 10.

[0055] The component 10 is advantageously a part of a turbomachine, in particular a gas turbine, particularly advantageously a part subjected to a hot gas in usage of the turbine.

[0056] The component 10 furthermore comprises a region B. The region B is advantageously a surface region. In the region B, the component 10 was provided with a defined pore pattern PM during its additive production according to the presently described method. The pore pattern PM is indicated in FIG. 1 by a contrast within a solid body of the component. The bright regions within the pore pattern PM can represent, for example, pores or small cavities.

[0057] During the additive production, such a pore pattern may be generated or intentionally set, for example, by corresponding selection or corresponding setting of an irradiation parameter, such as a scanning or radiation speed v or, for example, an irradiation power or laser power P. An energy introduction, which can essentially be defined from laser power and scanning speed, is advantageously decisive in this case. With strongly elevated energy introduction, material is vaporized, for example, which can result in pore formation. With excessively low energy introduction, the melt pools can break away or material can partially be inadequately re-melted. Both can be intentionally used to generate a recognizable pattern.

[0058] A particularly high irradiation power and/or a low scanning speed, for example, in comparison to a standard or normal method or parameter set, can be set for the additive production process of the component 10 to form the defined porosity and/or defined surface roughness (cf. FIG. 2 below).

[0059] Vice versa and with the same result, the porosity or the surface roughness can be set, for example, by a particularly low irradiation power and/or a particularly high scanning speed (in comparison to a standard or normal method or parameter set). In other words, in both described cases a deficient powder solidification can be achieved, which is capable of inducing the desired defined surface roughness.

[0060] In each case in relation to a standard or normal process, which induces, for example, a material density of 99.5% or a porosity of 0.5%, respectively, the porosity according to the invention in the region Bfor example, due to locally adapted process parameterscan be between 3% and 5%, in particular 4%.

[0061] An irradiation power can describe, for example, a laser power of a focused laser beam in a range between 100 W and 500 W, wherein a low irradiation power is located at the lower boundary of the range and a high irradiation power is located at the upper boundary of the range.

[0062] A scanning speed can describe, for example, a speed of the energy beam in a range between 100 mm/s and 1000 mm/s, wherein a low scanning speed is located at the lower boundary of the range and a high scanning speed is located at the upper boundary of the range.

[0063] The pore pattern PM is advantageously set below the surface OF, so that the surface OF of the component 10 itself is advantageously free of pores and/or cracks.

[0064] The component is advantageously provided with the porosity in a depth of less than 500 m below the surface OF, so that the subcutaneous porosity induces or generates a defined surface roughness in the region B (cf. FIG. 2).

[0065] The region B is advantageously an identification region, which can be automatically analyzed and/or compared to a database by an identification unit, for example, an optical or optical measuring unit, to identify the component.

[0066] The region B can have, for example, dimensions of 1515 mm with a depth of approximately 1 mm (cf. FIG. 3). Furthermore, the region is advantageously dimensioned in such a way that it can be penetrated by a radiographic examination and/or material examination, for example, by an x-ray or computer tomography and/or transmission electron microscopy, and the pore pattern PM can thus be registered or recorded.

[0067] The region B canin contrast to what is shown in the illustration of FIG. 1represent only a particularly small part of the surface OF of the component or describe it. The region B can furthermore denote a concealed and/or a well-accessible surface region of the component. The region B advantageously corresponds to a nonfunctional surface region, for example, not a region which faces toward a flow relevant for the function of the component or is flow-active in usage of the component.

[0068] FIG. 2 shows a schematic side view of the component 10 in a simplified illustration. The mentioned defined surface roughness of the component 10 and/or a surface in the region B is provided with the reference sign OR. The region B can be seen at the top left in the view (cf. dashed lines). In the region B, the pore pattern PM or the porosity is indicated by dots. It is provided that the pores are arranged in the interior of the component or under the surface OF. Under the surface OF, the pores advantageously induce the surface roughness OR, wherein the surface OF itself is free of pores, however, so as not to impair the component. In particular at temperatures subjected to hot gas, a surface porosity would be disadvantageous, since cracks could result originating therefrom and oxidation or corrosion of the components would be more probable.

[0069] FIG. 3 schematically shows a top view or a sectional view of an at least partially additively produced component. Alternatively or additionally, solely an irradiation pattern BM for a layer to be solidified (cf. top view) can be indicated.

[0070] The irradiation or exposure pattern BM comprises contour irradiation vectors KBV, which advantageously only irradiate an outline of the component 10 (advantageously observed in a top view of the powder bed), to correct buildup or irradiation errors, and/or to produce a correspondingly smooth surface.

[0071] The irradiation or exposure pattern BM furthermore comprises surface irradiation vectors FBV1, FBV2. The surface irradiation vectors FB are approximately horizontal irradiation paths aligned parallel to one another, according to which the energy beam 2 is advantageously guided over the powder bed to remelt and solidify it and/or the component material. A spacing of the surface irradiation vectors FBV (not explicitly identified) is advantageously defined by further irradiation parameters such as the laser power or the powder particle size and/or further parameters.

[0072] Furthermore, surface irradiation vectors FBV2 are shown in the left region of the component layer shown, which only have a length L. By way of a selective irradiation of a starting or component material for the component 10 along the surface irradiation vectors FBV2, the advantages according to the invention can be used and the surface roughness OR (cf. FIG. 2) can be set alternatively to the above-described variation or setting of the irradiation parameters. The defined surface roughness OR can advantageously be set in the region B by surface irradiation vectors FBV2 having a length L of less than 500 m, particularly advantageously less than 300 m, being provided in an edge region or along a contour of the component 10 as shown in FIG. 3.

[0073] The longer surface irradiation vectors FBV1 which are furthermore shown can be associated with an irradiation pattern of the prior art.

[0074] Although this is not explicitly identified in FIG. 3, a similar effect, i.e., a similar tailoring or customization of the surface roughness OR can be achieved by a spacing of 50 m to 500 m, particularly advantageously between 80 m and 300 m, being set or provided between a surface irradiation vector FBV1 (in skin irradiation) and a contour irradiation vector KBV in the region B. In this manner, a corresponding pore formation for the pore pattern is induced with increased probability due to the complicated melting and solidification processes during the additive production. Such a situation would arise if the surface irradiation vectors FBV2 were omitted in FIG. 3, but the above-mentioned spacings were set or provided. Then, similarly as in the case of a reduced laser power, for example, a desired porosity or deficient solidification of base or component material would result in the region B.

[0075] Furthermore, a depth T is shown in FIG. 3. The depth T advantageously corresponds to a distance perpendicular to the surface OF of the component 10, in which the pore pattern PM is to be provided according to the invention to generate the surface roughness OR. The depth T can describe an amount between 5 and 15 layer thicknesses.

[0076] The described pore pattern PM advantageously represents a random pore pattern. It is to be noted that pores arise randomly in the arrangement and dimensions thereof due to an individual and/or random selection of the irradiation parameter and/or the irradiation pattern and thus the component 10 can be made forgery-proof and unambiguously identifiable and/or registered as described. A frame (not explicitly identified) can also be placed around the region B during the buildup, for example, structurally or by visual identification, for the identification or registration.

[0077] The surface roughness OR can be set, for example, by a computer automatically, by corresponding selection of irradiation pattern and/or irradiation parameter, which can be taken, for example, from a database. Furthermore, the surface roughness OR can be acquired, for example, by optical measuring or scanning methods.

[0078] It can also be provided according to the invention that the defined surface roughness is applied in or on an already prefinished component, for example, to characterize, identify, or certify it later for a defined producer.

[0079] The invention is not restricted thereto by the description on the basis of the exemplary embodiments, but rather comprises every novel feature and every combination of features. This includes in particular every combination of features in the patent claims, even if this feature or this combination is itself not explicitly specified in the patent claims or exemplary embodiments.