Method for the manufacture of a component for high thermal loads, a component producible by this method and an aircraft engine provided with the component

Abstract

A method for manufacturing a thermally deformable component for high thermal loads, includes: providing a first area of the component with a first metallic material by a generative laser process, or making the first area of the first metallic material; providing a second area of the component with a second metallic material by a generative laser process, or making the second area of the second metallic material; where at least one of the metallic materials is deposited by the generative laser process, and a ratio of a linear expansion coefficient .sub.1 of the first metallic material and of a linear expansion coefficient .sub.2 of the second metallic material is as: $\frac{{}_2\left(T_2\right)}{{}_1\left(T_1\right)}=x\frac{.Math.T_1-T_0.Math.}{.Math.T_2-T_0.Math.},$
where x=0.5 to 1; T.sub.1=mean operating temperature on a hot side; T.sub.0=reference temperature; T.sub.2=mean operating temperature on a cold side.

Claims

1. A method for manufacturing a thermally deformable component for high thermal loads, comprising: a) providing that a first area on a first side of the component exposed to a first mean operating temperature is provided with or made of a first metallic material, b) providing that a second area on a second side of the component exposed to a second mean operating temperature is provided with or made of a second metallic material, wherein the first mean operating temperature is higher than the second mean operating temperature, c) providing that at least one of the first and second metallic materials is deposited by a generative laser process, and d) wherein, a ratio of the linear expansion coefficient .sub.1 of the first metallic material and of the linear expansion coefficient .sub.2 of the second metallic material is as follows: $\frac{{}_2\left(T_2\right)}{{}_1\left(T_1\right)}=x\frac{.Math.T_1-T_0.Math.}{.Math.T_2-T_0.Math.},$ where x is a range0.5 and 1; and T.sub.1 is the first mean operating temperature; T.sub.0 is a reference temperatureroom temperature; and T.sub.2 is the second mean operating temperature.

2. The method in accordance with claim 1, wherein the generative laser processes include at least one of selective laser melting, laser cladding, selective laser sintering or direct laser deposition.

3. The method in accordance with claim 1, and further comprising providing that one of the first and second metallic materials not deposited by a generative laser process is a casting.

4. The method in accordance with claim 1, wherein the first material is selected from a group consisting of Ni-12Cr-6Al-4Mo-0.7Ti, Ni-15Cr-10Co-8Mo-4.2Al-3.6Ti, Ni-10Co-10W-9Cr-5.5Al-2.5Mo-1.5Ti, Ni-10Co-10W-8.3Cr-5.5Al-3Ta-1Ti-0.7Mo, Ni-15Co-9.5Cr-5.5Al-4.7Ti-3Mo-1V; Ni-9.6Co-6.5Ta-4.6Cr-6.4W-5.6Al-3Re-1Ti, as well as intermetallic phases from the group of aluminides and silicides.

5. The method in accordance with claim 1, wherein the second material is selected from a group consisting of Ni-20Cr-20Co-6Mo-2Ti and 43.5Ni/Co-16.5Cr-3.3Mo-1.2Al-1.2Ti.

6. The method in accordance with claim 1, and providing the component a sequence of areas i=1, . . . N, where for adjacent areas, a following equation applies: $\frac{{}_{i+1}\left(T_{i+1}\right)}{{}_i\left(T_i\right)}=x\frac{.Math.T_i-T_0.Math.}{.Math.T_{i+1}-T_0.Math.}.$

7. The method in accordance with claim 1, and building up a cooling element on the component by at least one chosen from selective laser sintering and selective laser melting.

8. The method in accordance with claim 1, wherein a ratio of thermal conductivities .sub.1, .sub.2 is as follows: $\frac{{}_1\left(T\right)}{{}_2\left(T\right)}=K,$ where K=0.2 to 1.5 for conductivities at room temperature and K1.5 for conductivities at the first mean operating temperature T.sub.1 at the first side of the component.

9. The method in accordance with claim 1, and providing that the metallic material of the second area includes a concentration of at least one chosen from copper and aluminum.

10. The method in accordance with claim 1, wherein, after application of metallic material to at least one of the first area or the second area, performing at least one of heat treating or hot isostatic pressing on the component.

11. The method in accordance with claim 1, and forming at least one of a boundary surface or transition area between the metallic materials between the first area and the second area.

12. A component produced by the method in accordance with claim 1, comprising a sequence of areas i=1, . . . N, including: the first area of the first metallic material; and the second area of the second metallic material; where adjacent areas of the sequence of areas follow: $\frac{{}_{i+1}\left(T_{i+1}\right)}{{}_i\left(T_i\right)}=x\frac{.Math.T_i-T_0.Math.}{.Math.T_{i+1}-T_0.Math.}.$

13. The component in accordance with claim 12, wherein the component is at least one chosen from a component in an inlet area of a turbine, a stator vane of the turbine, a wall of the turbine, a heat shield, a lining element with a cooling structure and a lining of a combustion chamber.

14. The component in accordance with claim 12, wherein under a thermal load with a temperature gradient, a difference between a thermal expansion .sub.1 of the first metallic material on the first side of the component and the thermal expansion .sub.2 of the second metallic material on the second side of the component is reduced as compared with a component made from only one of the first and second metallic materials.

15. The component in accordance with claim 12, wherein ratio of thermal conductivities .sub.1, .sub.2 is as follows: $\frac{{}_1}{{}_2}=K,$ where K=0.2 to 1.5 for conductivities at room temperature, and K1.5 for conductivities at the first mean operating temperature T.sub.1 on the first side of the component.

16. The component in accordance with claim 12, wherein the metallic material of the second area includes a concentration of at least one chosen from copper or aluminum.

17. The component in accordance with claim 12, further comprising a cooling structure.

18. The component in accordance with claim 12, wherein between the first area and the second area, at least one of a boundary surface or a transition area between the metallic materials is provided.

19. An aircraft engine provided with a component according to claim 12, where the component is arranged in at least one chosen from an inlet area of a turbine, a stator vane of the turbine, a wall of the turbine, a heat shield and a lining of a combustion chamber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, the present invention is described in greater detail in light of the figures of the accompanying drawing showing several exemplary embodiments.

(2) FIG. 1A (Prior Art) shows a schematic representation of a component in accordance with the state of the art made from one metallic material.

(3) FIG. 1B shows a schematic representation of a component in accordance with an embodiment of the present invention, made from two different metallic materials.

(4) FIG. 2 shows a sectional view through an embodiment of a component having a cooling structure.

(5) FIG. 3A shows a schematic representation of a multi-material system.

(6) FIG. 3B (Prior Art) shows a schematic representation of a single-material system.

DETAILED DESCRIPTION

(7) FIG. 1A (Prior Art) shows schematically a component 10 in the form of a cuboid and made from one metallic material. The component 10 is subjected on its bottom side to a relatively high temperature T1, and on its upper side to a lower temperature T2. There is thus a temperature gradient in the arrow direction, i.e. the heat flows from the bottom side to the upper side of the component 10.

(8) Since the component 10 is made homogeneously from one metallic material, the linear expansion coefficient in the component 10 of the material is dependent solely on the temperature and rises as the temperature increases.

(9) Due to the locally differing heating up (in particular due to the temperature gradient), the material of the component 10 however expands differently in the various areas, i.e. there are locally differing expansions .sub.1, .sub.2. In the hotter area of T.sub.1 (i.e. the bottom side of the component 10), the expansion .sub.1 is greater than in the cooler area of T.sub.2 (i.e. at the upper side of the component 10), i.e. the expansion .sub.2 is lower. Due to these expansions, the bottom side of the component 10 (i.e. the hot side) is thus under compressive stress, and the upper side of the component (i.e. the cold side) under tensile stress. In FIG. 1 the expansions are indicated by arrows. Longer arrows represent a greater expansion.

(10) The component 10 is generally deformable and not rigid under thermal load, i.e. it is not installed in such a way that deformation is not possible, for example. The differing expansions .sub.1, .sub.2 lead to the component 10 changing its geometrical shape, which is unwelcome. In this embodiment, the primary concern is therefore not the change in the internal stress distribution, but geometrical accuracy particularly under high thermal loads.

(11) FIG. 1B shows in an embodiment how deformations can be reduced or even prevented. To do so, the component 10 is built up of areas 1, 2 with two metallic materials.

(12) The temperature gradient again acts, as shown in connection with FIG. 1A, from the bottom side to the upper side. A lower area 1 of the component 10 facing the higher temperature T.sub.1 has a metallic material with a lower linear expansion coefficient .sub.1 than the upper area 2 facing the lower temperature T.sub.2: .sub.1<.sub.2.

(13) This means that the lower area 1, here designed as a layer 1, cannot expand as much relatively as the upper area 2, likewise designed as a layer. By suitable matching of the materials and of the corresponding thermal expansion coefficients .sub.1, .sub.2, it can be achieved that the expansions .sub.1, .sub.2 in the lower and upper layers approximate to one another or are even about equal, so that deformation of the component 10 is reduced or prevented. Furthermore, there are possibilities for cost savings when less expensive materials can be used for the cooler areas of the component 10 under certain circumstances.

(14) Advantageous embodiments can be provided for determining the linear expansion coefficients 1, 2 in the areas 1, 2. The following applies as a general principle:
.sub.1(T.sub.1)(T.sub.1T.sub.0)=.sub.1
.sub.2(T.sub.2)(T.sub.2T.sub.0)=.sub.2
The expansions .sub.1, .sub.2 thus depend on the temperature differences over the areas 1, 2 of the component 10 and on the linear expansion coefficients .sub.1, .sub.2. The temperature T.sub.0 is a reference temperature which can for example be the room temperature or a higher temperature.

(15) If the expansions .sub.1, .sub.2 in the areas 1, 2 of the component 10 are to be matched to one another, this can be achieved with the following condition:

(16) $\frac{{}_2\left(T_2\right)}{{}_1\left(T_1\right)}=x\frac{.Math.T_1-T_0.Math.}{.Math.T_2-T_0.Math.},$ where x is between 0.5 and 1. The temperatures T.sub.1, T.sub.2 must be understood here as mean temperatures in operation. T.sub.0 is a reference temperature.

(17) If during design the temperatures T.sub.1, T.sub.2, T.sub.0 of a component 10 are known and a factor x is selected, material pairs with suitable thermal expansion coefficients can be selected so that the deformations of the component 10 are reduced.

(18) An embodiment is described in more detail in the following on the basis of a numerical example and FIG. 3A and FIG. 3B (Prior Art).

(19) Here a multi-material system with two components and a clear-cut transition at the boundary surface (case 1, FIG. 3A) is compared with a single-material system (case 2, FIG. 3B (Prior Art)).

(20) In the present case, the multi-material system features INCONEL 100 on the hotter side, and C 263 on the cooler side. The single-material system has INCONEL 100 all the way through.

(21) In the present case, the temperature on the cooler side should be 800 C., and on the hotter side 1000 C. The temperature is 900 C. at the boundary surface between the two material systems.

(22) When a boundary surface is mentioned here, this can in other embodiments also be a transition area between two material systems. It is thus possible, in particular when powders are Lased, that mixing occurs, so that in the finished component 10 no firm boundary surface exists. It is also possible that in another embodiment, a connecting layer (for example a braze layer) is arranged between two material areas 1, 2. Room temperature is assumed here as the reference temperature T.sub.0.

(23) TABLE-US-00001 Material 1: INCONEL 100 Material 1 = material 2: Material 2: C263 INCONEL 100 .sub.1(1000 C.) = 1.6E5 1/K .sub.1 (1000 C.) = 1.6E5 1/K .sub.2 (800 C.) = 1.7E5 1/K .sub.1 (900 C.) = 1.5E5 1/K .sub.1 (900 C.) = 1.5E5 1/K .sub.1 (800 C.) = 1.4E5 1/K .sub.2 (900 C.) = 1.8E5 1/K

(24) The thermal expansions are calculated as follows:

(25) TABLE-US-00002 Case 1: hot side Case 2: hot side .sub.1 = .sub.1(1000 C.) (1000 C. .sub.1 = .sub.1(1000 C.) (1000 C. 21 C.) = 1.6E2 21 C.) = 1.6E2 Case 1: boundary surface Case 2: boundary surface .sub.1 = .sub.1(900 C.) (900 C. .sub.1 = .sub.1(900 C.) (900 C. 21 C.) = 1.3E2 21 C.) = 1.3E2 .sub.2 = .sub.2(900 C.) (900 C. 21 C.) = 1.6E2 Case 1: cold side Case 2: cold side .sub.2 = .sub.2(800 C.) (800 C. .sub.1 = .sub.1(800 C.) (800 C. 21 C.) = 1.3E2 21 C.) = 1.1E2

(26) This makes clear that in the case of the multi-material system the difference in the expansions (.sub.1.sub.2) is at 0.3 E-2 less than in the case of the single-material system (0.5 E-2). This shows that the selected material system in case 1 is geometrically more accurate than the system according to case 2. However, the example also shows that shear stresses occur in the area of the boundary surface.

(27) The value x from the equation for the ratio of the linear expansion coefficients is 0.85.

(28) Alternatively or additionally, material pairs can be specified on the basis of conditions for the conductivity . At room temperature, the following applies:

(29) $\frac{{}_1}{{}_2}=y,$ where y=0.2 to 1.5. .sub.1 is the thermal conductivity of the first area 1 of the component 10 (hot side), .sub.2 is the thermal conductivity of the second area 2 of the component 10 (cold side). Furthermore, the following applies for a typical mean operating temperature T.sub.1 of an aircraft turbine:

(30) 0$\frac{{}_1}{{}_2}=z,$ where z1.5.

(31) The metallic material of the first layer 1 can be, for example: Ni-12Cr-6Al-4Mo-0.7Ti (example: INCONEL 713), Ni-15Cr-10Co-8Mo-4.2Al-3.6Ti (example: C1023), Ni-10Co-10W-9Cr-5.5Al-2.5Mo-1.5Ti (example: MAR-M 2460), Ni-10Co-10W-8.3Cr-5.5Al-3Ta-1Ti-0.7Mo (example: MAR-M2470), Ni-15Co-9.5Cr-5.5Al-4.7Ti-3Mo-1V (example: INCONEL 100) and Ni-9.6Co-6.5Ta-4.6Cr-6.4W-5.6Al-3Re-1Ti (example: CMSX4) as well as intermetallic phases from the group of aluminides or silicides. Advantageous embodiments for the second material have a nickel-based alloy, in particular Ni-20Cr-20Co-6Mo-2Ti (example: 0263) and/or 43.5Ni/Co-16.5Cr-3.3Mo-1.2Al-1.2Ti (PE16).

(32) Advantageous pairs of materials are in particular also:

(33) TABLE-US-00003 Hot side (first layer 1) Cold side (second layer 2) Ni10Co10W9Cr5.5Al2.5Mo1.5Ti Ni20Cr20Co6Mo2Ti Ni15Co9.5Cr5.5Al4.7Ti3Mo1V Ni20Cr20Co6Mo2Ti Ni9.6Co6.5Ta4.6Cr6.4W5.6Al3Re1Ti Ni20Cr20Co6Mo2Ti

(34) In further embodiments, elements with high heat conductance and thermal expansion can be selectively used in the cold second area 2. An example for this is copper and/or aluminum. Increasing the concentration of these metals in the second area 2 also achieves a reduction in the deformations.

(35) In a further embodiment of the method, a heat treatment and/or hot isostatic pressing follows the application of the first area 1 and/or of the second area 2.

(36) FIG. 1B shows, for reasons of clarity, a component 10 with two areas 1, 2 (as layers). In alternative embodiments, the component 10 has a layer structure having a sequence of areas with metallic materials, where the linear expansion coefficients meet the following conditions relatively to one another:

(37) $\frac{{}_{i+1}\left(T_{i+1}\right)}{{}_i\left(T_i\right)}=x\frac{.Math.T_i-T_0.Math.}{.Math.T_{i+1}-T_0.Math.}$ Hence a finer graduation of the material properties is possible with more than two areas (i=2, 3, 4, 5 . . . ).

(38) In these ways, it is for example possible to build up a kind of layer structure with three or more areas 1, 2 of differing materials. It is not essential here that the thickness of the layers is identical over the entire layer system. In any event, the result is a layer system with graduated properties, i.e. properties matched to one another.

(39) FIG. 1B shows two areas 1, 2 of which the material properties are matched to one another. All areas 1, 2 here can be built up by a generative laser process. Alternatively, at least one first area 1, 2 can represent a substrate that is for example a casting. The second area 2, 1 can then be applied to this substrate using a generative laser process. With this embodiment, the material properties (in particular the expansion coefficients) of the casting and the applied area must then be matched to one another according to the above statements.

(40) The illustration in FIG. 1B represents the schematic structure of a double layer applied by generative laser processes.

(41) The generative laser processes include in particular laser cladding, selective laser sintering (SLS), selective laser melting (SLM) and direct laser deposition (DLD).

(42) The methods can also be combined for the manufacture of components. In all cases, metallic layers are generated by laser radiation on a substrate.

(43) With laser cladding, components 10 can be built up with graduated layer systems, so that properties such as the thermal expansion coefficient and the heat conductance can be selectively set locally. The layers are built up by melting of the material in question (in powder form or as a wire). It is thus possible to precisely apply layers with thicknesses between 0.1 mm and several centimeters. The applied material here forms a bond with the substrate underneath it. Further advantages are that a wide range of materials can be applied and the heat input into the substrate itself is relatively low. However, no undercuts can be manufactured using this method.

(44) With selective laser sintering, a spatial structure is manufactured by sintering from a powder-like starting material. With the layer-by-layer build-up of the layers by selective melting of the powder by a laser from the powder bed, components with undercuts can also be obtained here. If during melting of the powder-like material no bonding agents are used, but instead the metallic powder is completely melted on, this is called selective laser melting.

(45) It is thus possible in particular to combine selective laser sintering and laser cladding with one another. The combination is particularly useful when different strengths of the methods have to be exploited. In laser cladding, it is relatively easy to change the materials since the powder is blown onto the welding point. With this method however, complex component geometries are difficult to manufacture. By contrast, with laser sintering complex component geometries are easily producible, but the change of material is more difficult, since the powder is in the form of a bed. Hence both methods are complementary.

(46) FIG. 2 shows in schematic form the cross-section through a component 10 that has a cooling structure 20 with a complex geometry. The cooling structure 20 here has a first element 21 and a second element 22, with cooling gas flowing through the space in between. The elements 21, 22 are connected to one another in areas not shown in FIG. 2, so that a temperature gradient over the component 10 also leads to a deformation of the component 10.

(47) The details of the cooling structure 20 have for example undercuts 23 which can be efficiently manufactured by the generative laser processes.

(48) The hot temperature T.sub.1 applies on the bottom side of the component 10, the first element 21, and the temperature T.sub.2 which is cooler relatively thereto on the upper side, the second element. Hence the first element 21 represents the first area 1, the second element 22 the second area 2. For the linear expansion coefficients .sub.1, .sub.2, the relationship obtained in connection with FIG. 1B applies.

LIST OF REFERENCE NUMERALS

(49) 1 First area of the component

(50) 2 Second area of the component

(51) 10 Component

(52) 20 Cooling structure

(53) 21 First element of the cooling structure

(54) 22 Second element of the cooling structure

(55) 23 Undercut on cooling structure

(56) T.sub.0 Reference temperature (e.g.: room temperature)

(57) T.sub.1 Temperature on the bottom side of the component

(58) T.sub.2 Temperature on the upper side of the component

(59) .sub.1 Linear thermal expansion coefficient, first area

(60) .sub.2 Linear thermal expansion coefficient, second area

(61) .sub.1 Expansion of lower (hot side) layer

(62) .sub.2 Expansion of upper (cold side) layer