METHOD OF MANUFACTURE OF A COMPONENT

Abstract

A method for the manufacture of a component having a defined geometry and dimensions is described. In sequence, the steps of the method involve; a) using an additive layer manufacturing process, budding a three-dimensional net shape of the component; b) applying a subtractive surface finishing operation to the product of step a); c) applying a heat treatment to the product of step b) whereby to provide a component to the defined geometry and dimensions.

Claims

1. A method for the manufacture of a component having a defined geometry and dimensions comprising, in sequence; a) using an additive layer manufacturing process, building a three-dimensional net shape of the component; b) applying a subtractive surface finishing operation to the product of step a); c) applying a heat treatment to the product of step b) whereby to provide a component to the defined geometry and dimensions.

2. A method as claimed in claim 1 wherein the subtractive surface finishing operation removes not more than 2 mm from the surface of the product of step a).

3. A method as claimed in claim 1 wherein the net shape comprises interim shape elements and the interim shape elements differ with respect to the component defined geometry and/or dimensions such that during the heating step, the interim shape elements adjust to form the defined component defined geometry and dimensions.

4. A method as claimed in claim 1 wherein the component defined geometry and dimensions includes a tolerance range within which the product of step c) is included.

5. A method as claimed in claim 1 wherein the finishing operation of step b) is selected from; a low stress grinding process, electrochemical grinding, abrasive flow machining, mechanical polishing, chemical polishing, chemical-mechanical polishing, buffing, burnishing, soda blasting, brushing and linishing.

6. A method as claimed in claim 1 wherein the finishing operation of step b) is a milling or turning operation wherein the feeds are maintained at or below 0.04 mm/rev and cuts are to a depth of 2 mm or less.

7. A method as claimed in claim 1 further including, in the additive layer manufacturing process step providing sacrificial support elements which are removed in an interim step preceding the surface finishing operation.

8. A method as claimed in claim 1 wherein the additive layer manufacturing process of step a) involves fusing of a powder which comprises a ferrous or non-ferrous alloy, or a ceramic.

9. A method as claimed in claim 8 wherein fusing of the powder is achieved using a laser or an electron beam.

10. A method as claimed in claim 1 wherein the additive layer manufacturing process of step a) is a powder bed process.

11. A method as claimed in claim 1 wherein the heat treatment of step c) is hot isostatic pressing (HIP).

12. A method as claimed in claim 1 wherein the heat treatment is selected from annealing, normalising or tempering.

Description

BRIEF DESCRIPTION OF ACCOMPANYING FIGURES

[0032] Embodiments will now be described by way of example only, with reference to the Figures, in which:

[0033] FIG. 1 is a sectional side view of a gas turbine engine which may comprise components made in accordance with the method of the invention;

[0034] FIG. 2 shows schematically an additive layer manufacturing method known to be used in prior art manufacturing;

[0035] FIG. 3 shows an embodiment of a method in accordance with the invention.

DETAILED DESCRIPTION OF FIGURES AND EMBODIMENTS

[0036] With reference to FIG. 1, a gas turbine engine is generally indicated at 10, having a principal and rotational axis 11. The engine 10 comprises, in axial flow series, an air intake 12, a propulsive fan 13, an intermediate pressure compressor 14, a high-pressure compressor 15, combustion equipment 16, a high-pressure turbine 17, and intermediate pressure turbine 18, a low-pressure turbine 19 and an exhaust nozzle 20. A nacelle 21 generally surrounds the engine 10 and defines both the intake 12 and the exhaust nozzle 20.

[0037] The gas turbine engine 10 works in the conventional manner so that air entering the intake 12 is accelerated by the fan 13 to produce two air flows: a first air flow into the intermediate pressure compressor 14 and a second air flow which passes through a bypass duct 22 to provide propulsive thrust. The intermediate pressure compressor 14 compresses the air flow directed into it before delivering that air to the high pressure compressor 15 where further compression takes place.

[0038] The compressed air exhausted from the high-pressure compressor 15 is directed into the combustion equipment 16 where it is mixed with fuel and the mixture combusted. The resultant hot combustion products then expand through, and thereby drive the high, intermediate and low-pressure turbines 17, 18, 19 before being exhausted through the nozzle 20 to provide additional propulsive thrust. The high 17, intermediate 18 and low 19 pressure turbines drive respectively the high pressure compressor 15, intermediate pressure compressor 14 and fan 13, each by suitable interconnecting shaft.

[0039] Other gas turbine engines to which the present disclosure may be applied may have alternative configurations. By way of example such engines may have an alternative number of interconnecting shafts (e.g. two) and/or an alternative number of compressors and/or turbines. Further the engine may comprise a gearbox provided in the drive train from a turbine to a compressor and/or fan.

[0040] Many components of the gas turbine engine could be manufactured by the method of the invention. For example (but without limitation), components in the turbine sections 17, 18 and 19, or the combustor 16 may be manufactured in accordance with the invention. The method is well suited to the manufacture of components with non-linear geometries.

[0041] FIG. 2 has been discussed above. FIG. 3 presents a flow chart of steps taken in sequence when performing a method in accordance with one embodiment of the invention.

[0042] 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.