METHODS FOR JOINING MATERIALS, AND MATERIAL COMPOSITE

Abstract

A method for joining materials, includes: providing a first material and a second material, providing the first material with a grid structure at a joining point, and joining, in particular soldering, the second material to the grid structure such that a material composite of the first material and the second material is produced, wherein the grid structure is designed in such a way that stresses in the material composite are at least partly compensated by the grid structure.

Claims

1. A method for joining materials, comprising: a) providing a first material and a second material, b) providing the first material at a connection point with a grid structure, wherein the grid structure is produced with an additive production method or selective laser melting or electron beam melting, and c) connecting or soldering, the second material to the grid structure so that a material compound is generated from the first material and the second material, wherein the grid structure is formed in such a manner that tensions in the material compound are at least partially compensated by the grid structure.

2. The method as claimed in claim 1, wherein the first material is a metallic material, or a nickel- or cobalt-based superalloy.

3. The method as claimed in claim 1, wherein the second material is a ceramic material, or a ceramic fiber composite.

4. The method as claimed in claim 1, wherein the grid structure is produced from the same material as the first material.

5. The method as claimed in claim 1, wherein the first material is produced with an additive production method, or selective laser melting or electron beam melting.

6. The method as claimed in claim 1, wherein the grid structure is produced in the same production method with the first material in order to form a composite component.

7. The method as claimed in claim 6, wherein the composite component is a part of a gas turbine, or a part of a gas turbine upon which hot gas acts.

8. The method as claimed in claim 1, wherein the second material is soldered via the grid structure to the first material and the grid structure is infiltrated with a solder/binder mixture.

9. A material compound produced and/or capable of being produced from a first material with a grid structure and a second material by the method according to claim 1, wherein the grid structure is connected directly and in a firmly bonded manner to the first material.

10. The material compound as claimed in claim 9, wherein the grid structure has grid struts with a diameter of between 0.5 mm and 2.5 mm.

11. The material compound as claimed in claim 9, wherein the grid structure has spatial diagonals of a corresponding elementary cell of the grid formed by the grid structure between 4 mm and 8 mm.

12. The material compound as claimed in claim 9, wherein an active solder is arranged between the grid structure and the second material and/or in grid spaces of the grid structure.

13. The material compound as claimed in claim 9, wherein the first material is a gas turbine component, or a component used in a hot gas path of a gas turbine.

14. The material compound as claimed in claim 9, which does not have a buffer or adhesion layer for balancing out mechanical tensions.

15. The material compound as claimed in claim 10, wherein the grid structure has grid struts with a diameter of 1.5 mm.

16. The material compound as claimed in claim 11, wherein the grid structure has spatial diagonals of a corresponding elementary cell of the grid formed by the grid structure of 6 mm.

17. The material compound as claimed in claim 12, wherein the active solder contains titanium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Further details of the invention are described below on the basis of the figures.

[0052] FIG. 1 shows a schematic sectional or side view of components of a material compound according to the invention.

[0053] FIG. 2 shows at least partially a schematic sectional or side view of the material compound.

[0054] FIG. 3 schematically indicates, on the basis of a flow chart, method steps of a method according to the invention for joining materials.

[0055] FIGS. 4 to 7 indicate tension conditions of the material compound according to the invention schematically and in a simplified form.

DETAILED DESCRIPTION OF INVENTION

[0056] In the exemplary embodiments and figures, identical elements or elements with the same effect can be provided in each case with the same reference numbers. The represented elements and their size ratios to one another should fundamentally not be regarded as true-to-scale, on the contrary, individual elements can be represented with exaggerated thickness or size dimensions for the purpose of ease of representation and/or better understanding.

[0057] A method for joining materials or a method for producing a material compound according to the present invention is described below on the basis of the figures.

[0058] The method is a method for joining or connecting materials, in particular a first material W1 and a second material W2. The method advantageously describes a soldering method for soldering first material W1 to second material 2 or vice versa.

[0059] In particular, the method comprises the provision of first material W1 (cf. a) in FIG. 3). The first material can be, for example, a metallic material. The first material can furthermore be present in the form of an element or a component, advantageously a turbine component or a component used, for example, in the hot gas path of a gas turbine. The first material can accordingly comprise a superalloy, for example, a nickel- or cobalt-based superalloy or be composed of this.

[0060] The stated alloy can be a superalloy which is precipitation-hardened or capable of being precipitation-hardened, for example, a superalloy hardened by the - or -phase or its phase precipitation. Alternatively, the first material can designate another material.

[0061] The method furthermore comprises the provision of second material W2. The second material can be a ceramic material. In particular, the second material can be a ceramic fiber composite material, for example, a CMC material (ceramic matrix composite). Alternatively, the second material can designate another material.

[0062] First material W1 is indicated at the bottom in FIG. 1, and second material W2 is indicated at the top in FIG. 1. A corresponding component, for example, a first component and a second component, can be designated synonymously respectively with the first material and the second material.

[0063] The method furthermore comprises providing first material W1 with a grid structure GS, and indeed at a connection point VS provided for the joining or the connection (cf. b) in FIG. 3). In FIG. 1, first material 1 is represented already provided or connected with/to grid structure GS advantageously in a firmly bonded manner.

[0064] Connection point VS advantageously designates an upper side of the first material or the corresponding element, which upper side is to be connected or joined to second material W2.

[0065] A relaxation of tension for a material compound generated from the first material and the second material should advantageously be brought about according to the invention via grid structure GS. Grid structure GS is accordingly advantageously arranged and formed in such a manner that tensions, i.e. mechanical, thermal and/or thermomechanical tensions, which would arise, for example, without the provision of grid structure GS in the case of a connection or soldering of the first material to the second material can be at least partially or substantially balanced out or compensated.

[0066] As a result of grid structure GS, an intermediate or buffer layer can advantageously be omitted, which layer is provided, for example, to balance out differences in the thermal coefficients of expansion of the components to be guided. As a further advantage, the joining according to the invention enables via a corresponding grid structure GS the formation of the material compound with particularly high temperature resistance which is improved in comparison with substances with conventional intermediate or buffer layers on a silver and/or copper basis.

[0067] A material compound which is produced according to the invention also advantageously has improved oxidation resistance in comparison with conventional or conventionally joined composite materials.

[0068] Grid structure GS can have, for example, grid spacings and/or grid diameters in the range of tenths of a millimeter up to a few millimeters or centimeters.

[0069] The grid structure can be a face centered cubic or fcc grid. Grid structure GS can furthermore have grid struts (not explicitly labeled) with a diameter of between 0.5 mm and 2.5 mm, in particular of 1.5 mm and spatial diagonals of a corresponding elementary cell of the grid with dimensions between 4 mm and 8 mm, in particular 6 mm.

[0070] Grid structure GS can also be functionally assigned to the component represented by the first material. In other words, according to the present invention, an element which is to be correspondingly joined and can be produced from the first material can be provided inherently during production with grid structure GS.

[0071] The first material and the grid structure are accordingly advantageously produced or capable of being produced from the same or identical materials.

[0072] An additive production method, for example, selective laser melting (SLM), electron beam melting (EBM) or also selective laser sintering is advantageously called on for advantageous and/or expedient production of the component of first material W1 and/or grid structure GS.

[0073] The design of grid structure GS in the structure of first material W1 or providing first material W1 with grid structure GS is therefore advantageously carried out in the same production method by means of additive methods in layers.

[0074] Grid structure GS is correspondingly advantageously connected in a firmly bonded manner to the first material and arranged directly thereon.

[0075] A corresponding connection point of the first material and providing this with grid structure GS for connection to the second material can in this sense already be intended in the production or provision of the first material.

[0076] The first material provided with grid structure GS advantageously represents a composite component VK which is provided for subsequent joining or connection to the second material.

[0077] Composite component VK can be, for example, a component which is manufactured or prefabricated monolithically or from one piece or the same material or the same type of material (metal) for a gas turbine or a hot gas part of a gas turbine. This can be a, in particular uncoated, turbine blade and/or a component of a turbine blade or combustion chamber, which component has advantageously not yet been provided with a heat insulation and/or oxidation protective coating.

[0078] The method further comprises connecting, in particular soldering, second material W2 to grid structure GS so that a material compound 10 (cf. FIG. 2) is generated (cf. c) in FIG. 3). In addition to composite component VK, only solder layers L and second material W2 are indicated schematically in FIG. 1.

[0079] Soldering is advantageously carried out by means known to the person skilled in the art and at correspondingly expedient temperatures, in particular at temperatures of above 700 C., advantageously above 800 C., for example, 1050 C.

[0080] In the case of soldering, in particular at least one of the componentsselected from grid structure GS and second materialis provided with the solder and the respective other component is then joined at the corresponding solder temperature. As represented in FIG. 1, both grid structure GS and second material W2 can initially, optionally with heating to a solder temperature, be provided with a solder and subsequently joined.

[0081] FIG. 2 shows material compound 10 which was generated by the method according to the invention from the first material and the second material.

[0082] In contrast to the representation in the figures, grid structure GS can be provided with a solder/binder mixture and/or a solder/filler mixture for soldering, or grid spaces of grid structure GS can be filled or infiltrated with the stated mixture. This can be advantageous both for the mechanical stability of material compound 10 and for the object according to the invention, i.e. for example balancing out mechanical tensions in material compound 10.

[0083] Material compound 10 shown in FIG. 2 advantageously has no buffer or adhesion layer for balancing out mechanical tensions.

[0084] FIG. 3 shows the method steps according to the invention on the basis of a flow chart.

[0085] The method step labelled with reference number a) relates to the provision of first material W1 and second material W2.

[0086] Method step b) relates to the provision of first material W1 with grid structure GS, as described above.

[0087] Method step c) relates to the connection, in particular soldering, of second material W2 to grid structure GS so thatas described abovematerial compound 10 is generated.

[0088] Alternatively, the connection of the first material and the second material can be performed by another joining method, for example, by welding, pressing, gluing, shaping or sintering.

[0089] FIG. 4 schematically shows an alternative formation of first material W1 provided with the grid structure in an analogous manner to the representation of FIG. 1. In the horizontal direction, first material W1 and grid structure GS connected thereto have a length or width L1. This length advantageously corresponds to the length of the corresponding components at room temperature RT.

[0090] FIG. 5 schematically shows the same structure from FIG. 1, wherein, however, additionally second material W2 was connected to the grid structure at a temperature T.sub.v (cf. above). Temperature T.sub.v corresponds, for example, to a temperature between 800 C. and 1050 C. or also more or less. In contrast to the representation of FIG. 4, it is apparent thatas a result of the thermal expansionfirst material W1 or corresponding material compound 10 has a length L2 greater than L1.

[0091] FIG. 6 schematically shows a cooling of material compound 10 from temperature T.sub.v (again) to room temperature RT. As a result of the cooling, first material W1 has reduced in size or contracted to length L3 (greater than L1 and L2), wherein, however, the corresponding length or width (not explicitly labeled) of second material W2 has not reduced in size to the same degree as a result of its material properties so that a first mechanical tension should exist via the connection between first material W1 and second material W2 and balanced out by grid structure GS.

[0092] Finally, in FIG. 7, the material compound is represented at a working temperature T.sub.A, wherein first material W1starting from room temperature RThas expanded to a length L4 (greater than L3). At the same time, as a result of the increase in temperature, second material W2 also expands, for example, slightly in terms of length. It is, however, apparent on the basis of the smaller difference in length that a second mechanical tensionwhich is also balanced out by grid structure GSis thus present. The second mechanical tension is advantageously smaller than the described first mechanical tension (cf. FIG. 6).

[0093] In other words, it is described on the basis of FIGS. 4 to 7 that grid structure GS is advantageously provided or first material W1 is provided with grid structure GS in such a manner that a relaxation of tension is adapted as expediently as possible to a hot state or to working temperature T.sub.A, i.e. an expediently lower mechanical tension prevails in material compound 10 in this hot or operating state and accordingly is or can be also advantageously balanced out via grid structure GS.

[0094] The invention is not restricted by the description on the basis of the exemplary embodiments to these, rather also encompasses any new feature and any combination of features. This contains in particular any combination of features in the claims even if this feature or this combination is itself not explicitly indicated in the claims or exemplary embodiments.