Method of manufacturing a component using a sinter joining process

Abstract

The production of engine parts with a complex geometrical structure. More particularly, a method for producing a complex part, comprising making available a first component, having a thermal expansion coefficient of the first component; a first joining surface; and a first bearing surface; making available a second component, having a thermal expansion coefficient of the second component; a second joining surface; a second bearing surface; and making available a jacket element, having a thermal expansion coefficient of the jacket element; and a jacket-element bearing surface; and heating the first component, the second component and the jacket element from a first temperature to a second temperature in order to carry out a joining process on the first component and the second component. Furthermore, a part, in particular for a gas turbine engine for an aircraft, and to a gas turbine engine of this kind.

Claims

1. A method for producing a complex part, comprising: providing a first component, including: a first thermal expansion coefficient; a first joining surface; and a first bearing surface; providing a second component, including: a second thermal expansion coefficient; a second joining surface; and a second bearing surface; and providing a jacket element, including: a third thermal expansion coefficient; and a jacket element bearing surface; positioning the first component and the second component to be brought into contact in at least a partial area of contact of the first joining surface and of the second joining surface, thus enabling a joint to be formed in the area of contact between the first joining surface and the second joining surface; providing that the jacket element at least partially surrounds the first component and the second component; positioning the jacket element bearing surface to be brought into contact with the first bearing surface and the second bearing surface; providing that the third thermal expansion coefficient of the jacket element is lower than the first thermal expansion coefficient of the first component and/or the second thermal expansion coefficient of the second component such that heating of the jacket element, the first component and the second component from a given first temperature to a given second temperature brings the jacket element bearing surface into contact with the first bearing surface and the second bearing surface through thermal expansion and thereby apply an opposing joining force between the first joining surface and the second joining surface; heating the first component, the second component and the jacket element from the first temperature to the second temperature in order to apply the opposing joining force between the first joining surface and the second joining surface through the thermal expansion to join the first component and the second component; providing that the joining of the first component and the second component is performed by a sinter joining method.

2. The method according to claim 1, and further comprising providing a gap between at least a partial area of the jacket element bearing surface and at least a partial area of the first bearing surface and at least a partial area of the second bearing surface at the first temperature, and further providing that the gap is closed at the second temperature to apply the opposing joining force.

3. The method according to claim 2, and further comprising dimensioning the gap around a periphery of the first component and the second component in such a way as to provide a directional force action on the first component and the second component by the jacket element.

4. The method according to claim 1, and further comprising providing a joining paste between the first joining surface and the second joining surface.

5. The method according to claim 1, and further comprising providing that the jacket element surrounds the first component and the second component over a full periphery of the first component and the second component in at least one section plane.

6. The method according to claim 1, and further comprising providing that the jacket element only partially surrounds a periphery of the first component and the second component in one section plane.

7. The method according to claim 1, and further comprising providing that the first component and the second component are formed from a sinterable material and are each in a presintered or fully sintered state.

8. The method according to claim 1, and further comprising providing that the first component and the second component are formed from a ceramic material or a metallic material.

9. The method according to claim 1, and further comprising providing a parting layer or a parting material between the jacket element and the first component and/or the second component in order to prevent formation of a bond between the jacket element and the first component and/or the second component.

10. The method according to claim 1, and further comprising providing that the first component and/or the second component are configured as a stator component or compressor stator component.

11. The method according to claim 1, and further comprising providing that the first joining surface and/or the second joining surface have/has a joining surface geometry to form at least a partial interlocking connection between the first component and the second component.

12. The method according to claim 1, wherein the jacket element only partially surrounds a periphery of the first component and the second component in a U-shape, in one section plane.

13. The method according to claim 1, wherein the first component and/or the second component are configured as a stator component or compressor stator component for a gas turbine engine for an aircraft.

14. A method for producing a complex part, comprising: providing a first component, including: a first thermal expansion coefficient; a first joining surface; and a first bearing surface; providing a second component, including: a second thermal expansion coefficient; a second joining surface; and a second bearing surface; and providing a jacket element, including: a third thermal expansion coefficient; and a jacket element bearing surface; positioning the first component and the second component to be brought into contact in at least a partial area of contact of the first joining surface and of the second joining surface, thus enabling a joint to be formed in the area of contact between the first joining surface and the second joining surface; providing that the jacket element at least partially surrounds the first component and the second component; positioning the jacket element bearing surface to be brought into contact with the first bearing surface and the second bearing surface; providing that the third thermal expansion coefficient of the jacket element is lower than the first thermal expansion coefficient of the first component and/or the second thermal expansion coefficient of the second component such that heating of the jacket element, the first component and the second component from a given first temperature to a given second temperature brings the jacket element bearing surface into contact with the first bearing surface and the second bearing surface through thermal expansion and thereby apply an opposing joining force between the first joining surface and the second joining surface; heating the first component, the second component and the jacket element from the first temperature to the second temperature in order to apply the opposing joining force between the first joining surface and the second joining surface through the thermal expansion to join the first component and the second component; providing that the first component and the second component are formed from a ceramic material or a metallic material.

15. A method for producing a complex part, comprising: providing a first component, including: a first thermal expansion coefficient; a first joining surface; and a first bearing surface; providing a second component, including: a second thermal expansion coefficient; a second joining surface; and a second bearing surface; and providing a jacket element, including: a third thermal expansion coefficient; and a jacket element bearing surface; positioning the first component and the second component to be brought into contact in at least a partial area of contact of the first joining surface and of the second joining surface, thus enabling a joint to be formed in the area of contact between the first joining surface and the second joining surface; providing that the jacket element at least partially surrounds the first component and the second component; positioning the jacket element bearing surface to be brought into contact with the first bearing surface and the second bearing surface; providing that the third thermal expansion coefficient of the jacket element is lower than the first thermal expansion coefficient of the first component and/or the second thermal expansion coefficient of the second component such that heating of the jacket element, the first component and the second component from a given first temperature to a given second temperature brings the jacket element bearing surface into contact with the first bearing surface and the second bearing surface through thermal expansion and thereby apply an opposing joining force between the first joining surface and the second joining surface; heating the first component, the second component and the jacket element from the first temperature to the second temperature in order to apply the opposing joining force between the first joining surface and the second joining surface through the thermal expansion to join the first component and the second component; providing that the first component and/or the second component are configured as a stator component or compressor stator component.

Description

(1) Illustrative embodiments of the present disclosure are described below with reference to the figures.

(2) In the figures:

(3) FIG. 1 shows a sectioned side view of a gas turbine engine according to the present disclosure;

(4) FIG. 2 shows a first illustrative arrangement of components to be joined in a jacket element as per the present disclosure;

(5) FIG. 3 shows a second illustrative arrangement of components to be joined in a jacket element as per the present disclosure;

(6) FIG. 4 shows a third illustrative arrangement of components to be joined in a jacket element as per the present disclosure;

(7) FIG. 5 shows a fourth illustrative arrangement of components to be joined in a jacket element as per the present disclosure;

(8) FIG. 6 shows a fifth illustrative arrangement of components to be joined in a jacket element as per the present disclosure; and

(9) FIG. 7 shows a method for producing a complex component as per the present disclosure.

(10) FIG. 1 illustrates a gas turbine engine 10 with a primary axis of rotation 9. The engine 10 comprises an air intake 12 and a fan 23 that generates two airflows: a core airflow A and a bypass airflow B. The gas turbine engine 10 comprises a core 11 that receives the core airflow A. When viewed in the order corresponding to the axial direction of flow, the core engine 11 comprises a low pressure compressor 14, a high pressure compressor 15, a combustion device 16, a high pressure turbine 17, a low pressure turbine 19 and a core thrust nozzle 20. An engine nacelle 21 surrounds the gas turbine engine 10 and defines a bypass duct 22 and a bypass thrust nozzle 18. The bypass airflow B flows through the bypass duct 22. The fan 23 is mounted on the low pressure turbine 19 by means of a shaft 26 and is driven by said turbine.

(11) In operation, the core airflow A is accelerated and compressed by the low pressure compressor 14 and directed into the high pressure compressor 15 where further compression takes place. The compressed air exhausted from the high pressure compressor 15 is directed into the combustion device 16, where it is mixed with fuel and the mixture is combusted. The resultant hot combustion products then expand through, and thereby drive, the high pressure and low pressure turbines 17, 19 before being exhausted through the nozzle 20 to provide some propulsive thrust. The high pressure compressor 15 is driven by the high pressure turbine 17 via an interconnecting shaft. Generally speaking, the fan 23 provides the majority of the propulsive thrust.

(12) Note that the terms “low pressure turbine” and “low pressure compressor” as used herein may be taken to mean the lowest pressure turbine stage and lowest pressure compressor stage (i.e. not including the fan 23) respectively and/or the turbine and compressor stages that are connected together by the interconnecting shaft 26 with the lowest rotational speed in the engine (i.e. not including the gearbox output shaft that drives the fan 23). In some literature, the “low pressure turbine” and “low pressure compressor” referred to herein may alternatively be known as the “intermediate pressure turbine” and “intermediate pressure compressor”. Where such alternative nomenclature is used, the fan 23 may be referred to as a first, or lowest pressure, compression stage.

(13) Other gas turbine engines to which the present disclosure may be applied may have alternative configurations. For example, engines of this kind may have an alternative number of compressors and/or turbines and/or an alternative number of interconnecting shafts. By way of further example, the gas turbine engine shown in FIG. 1 has a split flow nozzle 20, 22 meaning that the flow through the bypass duct 22 has its own nozzle that is separate to and radially outside the core engine nozzle 20. However, this is not limiting, and any aspect of the present disclosure may also apply to engines in which the flow through the bypass duct 22 and the flow through the core 11 are mixed, or combined, before (or upstream of) a single nozzle, which may be referred to as a mixed flow nozzle. One or both nozzles (whether mixed or split flow) may have a fixed or variable area. Whilst FIG. 1 relates to a turbofan engine, the disclosure may apply, for example, to any type of gas turbine engine, such as an open rotor (in which the fan stage is not surrounded by a nacelle) or turboprop engine, for example.

(14) The geometry of the gas turbine engine 10, and components thereof, is/are defined by a conventional axis system, comprising an axial direction (which is aligned with the rotational axis 9), a radial direction (in the bottom-to-top direction in FIG. 1), and a circumferential direction (perpendicular to the view in FIG. 1). The axial (X direction), the radial (Y direction) and the circumferential direction (Z direction) run perpendicular to one another.

(15) With further reference to FIG. 2, a first illustrative arrangement of components to be joined in a jacket element as per the present disclosure is illustrated.

(16) FIG. 2 shows a part 32, which is to be constructed from a first component 34a and a second component 34b. The first component 34a and the second component 34b rest against one another by means of the first joining surface 36a and the second joining surface 36b. A jacket surface 38 is provided with an opening 46, which, as illustrated in FIG. 2, is capable of accommodating the first component 34a and the second component 34b. A gap 50 is provided between the first bearing surfaces 40a,b,c of the first component 34a and the second bearing surfaces 42a,b,c of the second component 34b and the bearing surfaces of the jacket element 48a,b,c,d. In FIG. 2, by way of example, the gap 50 comprises four individual gaps 50a,b,c,d, which each form a clearance between the jacket element 38 and the first and second component 34a,b. In FIG. 2, the illustration of gap 50a,b,c,d is of a purely qualitative nature.

(17) Here, FIG. 2 can be a state of the kind found at the time of a first temperature before a joining process is carried out. The first and the second component 34a,b have been introduced into the opening 46 of the jacket element 38 and are spaced apart from the bearing surfaces 48a,b,c,d thereof by gaps 50a,b,c,d. If heating of the first and the second component 34a,b together with the jacket element 38 is then carried out, the respective elements expand by different amounts owing to the different thermal expansion coefficients of the first and the second component 34a,b and the jacket element 38. According to the invention, the thermal expansion coefficients of the first and the second component 34a,b are greater than the temperature expansion coefficient of the jacket element 38. Assuming suitable dimensioning, this means that, above a certain temperature, the gap 50 closes owing to the greater expansion of the first and the second component 34a,b relative to the jacket element 38. In this state, the first bearing surfaces 40a,b,c and the second bearing surfaces 42a,b,c then rest at least partially on the jacket-element bearing surfaces 48a,b,c,d. This is not illustrated in FIG. 2.

(18) The first bearing surfaces 40a,b,c and the second bearing surfaces 42a,b,c thus touch the bearing surfaces of the jacket element 48a,b,c,d at a defined temperature. If the temperature is then increased further, forces Fa, Fb, Fc and Fd emanating from the jacket-element bearing surfaces 48a,b,c,d act on the bearing surfaces of the first and the second component 34a,b, on the first bearing surfaces 40a,b,c and on the second bearing surfaces 42a,b,c. Owing to the geometrical dimensions as illustrated in FIG. 2, a force F1 and F2 due to force Fa and Fc then acts on the first and the second joining surface 36a,b of the first and the second component 34a,b. Essentially, the bearing surfaces 40b and 42b are supported on the bearing surfaces 48b and 48d of the jacket element and, owing to the continued increase in volume, exert the opposing forces F1 and F2 due to the different thermal expansion coefficients on the first and the second joining surface 36a,b.

(19) In the present case, there may be a preference, for example, to make gaps 50b and 50d larger than gaps 50a and 50c, and therefore, while bearing surfaces 40b and 42b rest on bearing surfaces 48b and 48d, there is still a residual gap 50b and 50d between bearing surfaces 40a, 40c and 42a and 42c and bearing surfaces 48a and 48d.

(20) If, to produce the part 32, the first component 34a, the second component 34b and the jacket element 38 are suitably heated in order to carry out a sinter joining process at the first joining surface 36a and 36b, a substantially integrally formed part 32 is formed after the sinter joining process. In other words, the first component 34a and the second component 34b are joined by means of the joining surfaces 36a,b.

(21) With further reference to FIG. 3, a second illustrative arrangement of components to be joined in a jacket element as per the present disclosure is illustrated.

(22) FIG. 3 differs from FIG. 2 only in that the jacket element 38 is not fully surrounded or closed in the form of a ring, as in FIG. 2, but has substantially a U shape. The mechanism of action in FIG. 3 is fundamentally comparable to the mechanism of action shown in FIG. 2. Owing to the U shape of the jacket element 38, however, forces Fa and Fc may not be substantially uniform over the full length of the first bearing surface 40b and the second bearing surface 42b owing to the different lever loading along the legs of the U, which is shown as open at the top in FIG. 3. At the same time, a force action Fb due solely to the friction between the first bearing surface 40b and the second bearing surface 42a relative to the jacket-element bearing surfaces 48b and 48d can be produced since there is no longer any opposing support in FIG. 3. The first component 34a together with the second component 34b is preferably arranged in such a way in the opening 46 in the jacket element 38 that no force action Fb occurs.

(23) Such a U shape of the jacket element 38 can preferably be employed in the case where the first component 34a and the second component 34a have complex geometrical structures which make it impossible, for example, to use a jacket element 38 in the form of a closed ring.

(24) Depending on the dimensions of the jacket element 38, of the first component 34a and of the second component 34b, the nonuniform force action Fa and Fc may affect the quality of the joint between the first joining surface 36a and the second joining surface 36b.

(25) With further reference to FIG. 4, a third illustrative arrangement of components to be joined in a jacket element as per the present disclosure is illustrated.

(26) Here, FIG. 4 corresponds to the embodiment in FIG. 2, but a joining paste 44 has been introduced between the first joining surface 36a and the second joining surface 36b. In this context, a joining paste 44 is composed of comparable or similar materials to the first component 34a and the second component 34b. The joining paste 44 is preferably used to assist the production of the joint between the first joining surface 36a and the second joining surface 36b in that the joining paste 44 can compensate for surface irregularities in the first and the second joining surface 36a,b. In FIG. 4, the joining paste 44 is illustrated in a purely qualitative manner and is not true to scale.

(27) With further reference to FIG. 5, a fourth illustrative arrangement of components to be joined in a jacket element as per the present disclosure is illustrated.

(28) FIG. 5 corresponds substantially to the structure in FIG. 2, with the difference of a first and second joining surface 36a,b which are not level but are instead offset. Such a design of the first and the second joining surface 36a,b while taking into account suitable gap dimensioning makes it possible to use not only force action Fa and Fc but also, in like fashion, Fb and Fd to produce the joint between the first and the second joining surface 36a,b. Thus, in FIG. 5, not only are there forces F1, F2 and F3, F4 acting in a horizontal direction but also forces F5 and F6 acting in a vertical direction on the two individual joining surfaces to form the joint between the first and the second joining surface 36a,b. A joint of this kind may presuppose suitable dimensioning of the gaps 50a,b,c,d.

(29) With further reference to FIG. 6, a fifth illustrative arrangement of components to be joined in a jacket element as per the present disclosure is illustrated.

(30) Here, FIG. 6 corresponds substantially to FIG. 2 but has a particular geometrical configuration of the first and the second joining surface 36a,b. Thus, one joining surface is surrounded over the full periphery on three sides by the other joining surface. This results not only in a nonpositive connection between the first and the second joining surface 36a,b but also, by virtue of the configuration or interlocking of the joining surfaces, in a positive connection.

(31) Production of the positive connection between the first joining surface 36a and the second joining surface 36b can be assisted through suitable dimensioning and selection of the materials for the first component 34a and the second component 34b. Thus, for example, the first component 34a and the second component 34b can comprise a slightly different material with slightly different thermal expansion coefficients and/or slight differences in a presintered state. Thus, for example, the second component 34a may be easy to introduce into the first component 34b before the sinter joining process but be connected to the latter in a substantially integral way after the sintering process has been carried out. For this purpose, the second component 34b has a slightly higher thermal expansion coefficient than component 34a, for example.

(32) The provision of a sinter joining paste 44 is likewise conceivable in all the embodiments in FIGS. 5 and 6.

(33) With further reference to FIG. 7, a method for producing a complex component as per the present disclosure is described.

(34) FIG. 7 shows a method (70) for producing a complex part (32), comprising making available (72) a first component (34a), having a thermal expansion coefficient of the first component; a first joining surface (36a); and a first bearing surface (40a, 40b, 40c); making available (74) a second component (34b), having a thermal expansion coefficient of the second component; a second joining surface (36b); and a second bearing surface (42a, 42b, 42c); and making available (76) a jacket element (38), having a thermal expansion coefficient of the jacket element; and a jacket-element bearing surface (48a, 48b, 48c, 48d); and heating (78) the first component (34a), the second component (34b) and the jacket element (38) from a first temperature to a second temperature in order to carry out a joining process on the first component (34a) and the second component (34b), wherein the first component (34a) and the second component (34b) can be brought into contact in at least a partial area of the first joining surface (36a) and of the second joining surface (36b), thus enabling a joint to be formed in the area of contact between the first joining surface (36a) and the second joining surface (36b); wherein the jacket element (38) at least partially surrounds the first component (34a) and the second component (34b); wherein the jacket-element bearing surface (48a, 48b, 48c, 48d) can be brought into contact with the first bearing surface (40a, 40b, 40c) and the second bearing surface (42a, 42b, 42c); wherein the thermal expansion coefficient of the jacket element is lower than the thermal expansion coefficient of the first component and/or the thermal expansion coefficient of the second component; and wherein the thermal expansion coefficient of the jacket element and the thermal expansion coefficient of the first component and/or the thermal expansion coefficient of the second component are designed in such a way as to bring the jacket-element bearing surface (48a, 48b, 48c, 48d) into contact with the first bearing surface (40a, 40b, 40c) and the second bearing surface (42a, 42b, 42c) and to bring the first joining surface (36a) and the second joining surface (36b) into contact in the heated state while the joining process is being carried out, with the result that the first joining surface (36a) and the second joining surface (36b) are subjected to an opposing force action.

(35) It will be understood that the invention is not limited to the embodiments above-described and various modifications and improvements can be made without departing from the concepts described herein. Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.

(36) Finally, attention is drawn to the fact that terms such as “having” or “comprising” do not exclude other elements or steps and that “a” or “an” does not exclude a plural. Elements which are described in connection with various embodiments can be combined. Reference signs in the claims should not be interpreted as restrictive.

LIST OF REFERENCE SIGNS

(37) 9 Main axis of rotation 10 Engine 11 Core 12 Air intake 14 Low pressure compressor 15 High pressure compressor 16 Combustion device 17 High pressure turbine 18 Bypass thrust nozzle 19 Low pressure turbine 20 Core thrust nozzle 21 Engine nacelle 22 Bypass duct 23 Fan A Core airflow B Bypass airflow 26 Interconnecting shaft 32 Part 34a,b First, second component 36a,b First, second joining surface 38 Jacket element 40a,b,c First bearing surfaces 42a,b,c Second bearing surfaces 44 Joining paste 46 Opening in jacket element 48a,b,c,d Jacket-element bearing surfaces 50a,b,c,d Gap 52a,b,c,d Force F.sub.a,F.sub.b,F.sub.c,F.sub.d Force on first/second component F.sub.1,F.sub.2,F.sub.3,F.sub.4,F.sub.5,F.sub.6 Force on joining surfaces 70 Method for producing a complex part 72 Making available a first component 74 Making available a second component 76 Making available a jacket element 78 Heating