Patent Application
20190128144
Engines, such as those which power aircraft and industrial equipment, may employ a compressor to compress air that is drawn into the engine and a turbine to capture energy associated with the combustion of a fuel-air mixture. Components of the engine may experience wear (e.g., corrosion, scratches, dents, nicks, cracks, material fatigue, abrasion, erosion, etc.) during the operating life of the engine. In some circumstances, it may be possible to replace a first instance of a component with a second instance of the component. For example, the second instance of the component may correspond to a spare instance of the component.
The amount/number of spares of a component that are available may be limited, such as for example if the component is no longer being produced/manufactured. The lack of spare component availability can significantly increase the cost of the spare component. Additionally, if a first instance of a component cannot be replaced with a second/spare instance of the component in a cost-effective/economical manner, an engine may need to be removed (e.g., retired) from service.
In order to mitigate a potential lack of availability of spare components, what is needed is an ability to restore a component to a state/condition acceptable for use in an engine. Additionally, what is needed is an ability to match one or more properties of the component following restoration to the properties of the component prior to restoration in order to ensure component quality and operability/functionality.
The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosure. The summary is not an extensive overview of the disclosure. It is neither intended to identify key or critical elements of the disclosure nor to delineate the scope of the disclosure. The following summary merely presents some concepts of the disclosure in a simplified form as a prelude to the description below.
Aspects of the disclosure are directed to a method comprising: removing a portion of a component that includes wear to generate a void in the component, where a material of the component has a first microstructure, depositing a filler material in the void, subjecting the filler material to a cold working technique to compress the filler material, and applying a heat treatment to cause the filler material to have a second microstructure that is matched to the first microstructure. In some embodiments, the portion of the component is removed via an application of at least one of water jet machining, electron discharge machining, laser machining, milling process or grinding. In some embodiments, the void consumes an entirety of a wall thickness of the component. In some embodiments, the method comprises attaching a fixture to the component prior to depositing the filler material in the void. In some embodiments, the subjecting of the filler material to the cold working technique includes rolling the filler material with a roller to produce the second microstructure. In some embodiments, the method comprises adjusting at least one of the filler material, a geometry of the roller, and a load applied by the roller to the filler material to adjust a degree of compression of the filler material. In some embodiments, the method comprises applying a heat treatment to the component prior to depositing the filler material. In some embodiments, the method comprises subsequent to subjecting the filler material to the cold working technique, depositing additional filler material in the void, where the heat treatment is applied subsequent to the subjecting of the filler material to the cold working technique, and where the application of the heat treatment causes the filler material to undergo grain recrystallization. In some embodiments, the heat treatment includes at least one of a solution heat treatment, a stabilization heat treatment, or a precipitation heat treatment. In some embodiments, the heat treatment reduces a stress that is induced in the component from an earlier application of a solution heat treatment to the component or the cold working technique. In some embodiments, the method comprises machining the component to a specified dimension subsequent to subjecting the filler material to the cold working technique. In some embodiments, the method comprises imparting a compressive residual stress on the component subsequent to the application of the heat treatment. In some embodiments, the imparting of the compressive residual stress includes subjecting the component to at least one of deep rolling, laser shock peening, ultrasonic peening, shot peen, or burnishing. In some embodiments, the filler material is deposited as part of an additive manufacturing technique or a welding technique. In some embodiments, the method comprises installing the component on an engine subsequent to subjecting the filler material to the cold working technique. In some embodiments, the component is one of a case, a rotor blade, a vane, a liner, or a nozzle, and the method comprises identifying the wear in the component, and based on identifying the wear, removing the component from the engine prior to removing the portion of the component. In some embodiments, the wear is identified based on at least one of a visual inspection, an acoustic technique, or an ultrasonic technique.
Aspects of the disclosure are directed to a case of an engine, comprising: a first portion with a first material that has a first microstructure, and a second portion with a second material that has a second microstructure, where the second microstructure is matched to the first microstructure, where the second material includes a plurality of layers, and where at least one layer of the plurality of layers includes a compressive residual stress. In some embodiments, each layer of the plurality of layers includes a compressive residual stress. In some embodiments, the first material includes a nickel alloy.
The present disclosure is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements. The figures are not necessarily drawn to scale unless explicitly indicated otherwise.
It is noted that various connections are set forth between elements in the following description and in the drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections are general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. A coupling between two or more entities may refer to a direct connection or an indirect connection. An indirect connection may incorporate one or more intervening entities.
In accordance with various aspects of the disclosure, apparatuses, systems, and methods are described for restoring a component (e.g., a component of an engine) to a state/condition suitable for service. In some embodiments, a property (e.g., a microstructure) of the component following restoration may substantially match the property (e.g., the microstructure) of the component prior to restoration (and potentially even prior to wear imposed on the component).
Aspects of the disclosure may be applied in connection with a gas turbine engine.
The engine sections 18-21 are arranged sequentially along the centerline 12 within an engine housing 22. Each of the engine sections 18-19B, 21A and 21B includes a respective rotor 24-28. Each of these rotors 24-28 includes a plurality of rotor blades arranged circumferentially around and connected to one or more respective rotor disks. The rotor blades, for example, may be formed integral with or mechanically fastened, welded, brazed, adhered and/or otherwise attached to the respective rotor disk(s).
The fan rotor 24 is connected to a gear train 30, for example, through a fan shaft 32. The gear train 30 and the LPC rotor 25 are connected to and driven by the LPT rotor 28 through a low speed shaft 33. The HPC rotor 26 is connected to and driven by the HPT rotor 27 through a high speed shaft 34. The shafts 32-34 are rotatably supported by a plurality of bearings 36 (e.g., rolling element and/or thrust bearings). Each of these bearings 36 is connected to the engine housing 22 by at least one stationary structure such as, for example, an annular support strut.
As one skilled in the art would appreciate, in some embodiments a fan drive gear system (FDGS), which may be incorporated as part of the gear train 30, may be used to separate the rotation of the fan shaft 32 from the rotation of the low speed shaft 33. For example, such an FDGS may allow the fan shaft 32 to rotate at a different (e.g., slower) speed relative to the low speed shaft 33.
During operation, air enters the turbine engine 10 through the airflow inlet 14, and is directed through the fan section 18 and into a core gas path 38 and a bypass gas path 40. The air within the core gas path 38 may be referred to as “core air”. The air within the bypass gas path 40 may be referred to as “bypass air”. The core air is directed through the engine sections 19-21, and exits the turbine engine 10 through the airflow exhaust 16 to provide forward engine thrust. Within the combustor section 20, fuel is injected into a combustion chamber 42 and mixed with compressed core air. This fuel-core air mixture is ignited to power the turbine engine 10. The bypass air is directed through the bypass gas path 40 and out of the turbine engine 10 through a bypass nozzle 44 to provide additional forward engine thrust. This additional forward engine thrust may account for a majority (e.g., more than 70 percent) of total engine thrust. Alternatively, at least some of the bypass air may be directed out of the turbine engine 10 through a thrust reverser to provide reverse engine thrust.
Wear (e.g., cracks) may be prone to developing at so-called high-stress locations. Such high-stress locations may exist at various interfaces of the housing 200. For example, the wear 204a is shown as existing proximate a flange 210. Similarly, the wear 204b is shown as existing proximate a boss 216. However, as reflected by the wear 204c, wear may be experienced distant from any particular interface/feature associated with the housing 200; e.g., the wear 204c may be experienced by/present in the bulk of the housing 200 in some instances.
While the component 200 illustrated in
Referring to
Referring to
In block 902, the wear 304 may be identified. For example, the wear 304 may be identified during an inspection (which may be a part of a scheduled or unscheduled maintenance procedure). One or more techniques may be used to identify the wear 304. For example, a visual inspection, an acoustic technique, an ultrasonic technique, etc., may be used to identify the wear 304 in block 902. The wear 304 may be identified when the component 300 is installed on an engine. Alternatively, the component 300 may be removed from the engine prior to the identification of the wear 304.
In block 906, a portion of the component 300 that includes the wear 304 may be removed. Application of a grinding/machining technique to the portion may be used in block 906. For example, and referring to
Whether the removal of block 906 adheres to a partial removal (e.g.,
In block 910, a solution heat treatment (e.g., solution annealing) may be applied to the component 300. The application of the solution heat treatment may dissolve any precipitates that may be present in the material of the component 300 and transform the material at, e.g., a solution annealing temperature into a single phase structure. As a result of the execution of block 910, the (material of the) component 300 may be easier to work with. For example, execution of block 910 may enhance the weldability of the component 300.
While the blocks 906 and 910 are shown in
In block 914, a fixture/backing plate may be coupled to the component 300. For example, as shown in
In block 918, filler material may be deposited in at least part of the void left by the removed portion (e.g., the portion 402 of
The material deposited in block 918 may be similar to a weld or cast microstructure (e.g., as molten metal is deposited and subsequently solidified). The material deposited in block 918 may be columnar in nature (e.g., may include columnar grains).
In some embodiments, the material deposited in block 918 may be subject to machining as indicated in block 920. The machining operation of block 920 may ensure that (a surface of) the deposited material is prepared for cold working as described below.
In block 922, the filler material may be subjected to one or more cold working procedures/techniques. Cold working may be imparted by one or more of compressing, stretching, and combinations thereof, among other types of cold working techniques. Compressing means pushing at least one surface of a body in order to deform the body by reducing at least one dimension of the body. Compressing may include rolling or forging. Stretching means pulling a body in order to deform the body by expanding at least one dimension of the body.
Based on the application of one or more cold working techniques in block 922 and/or the heat treatments of blocks 938 or 942 described further below, the microstructure may include fine, uniform equiaxed grains. For example,
In some embodiments, application of one or more cold working techniques (e.g., application of a roller) in block 922 may compress the filler material. For example, execution of block 922 may compress a nickel alloy within a range of 0.5 millimeters to 1 millimeter; a titanium alloy may be compressed 0.7 millimeters to 1 millimeter; an aluminum alloy may be compressed upwards of 1.5 millimeters. The degree/extent of compression may be based on one or more of the filler material, a geometry/form-factor of the roller, and a load applied by the roller to the filler material. Adjustments may be made during the execution of the method 900 (e.g., adjustments may be made “on the fly”) to adapt the extent/degree of compression that is obtained. One or more closed-loop/feedback mechanisms may be used to provide for the adjustments.
In block 926, a determination may be made whether additional filler material is to be added. If so (e.g., the “yes” path is taken out of block 926), flow may proceed to block 918. Otherwise if additional filler material is not needed (e.g., the “no” path is taken out of block 926), flow may proceed from block 926 to block 934 (see
In block 934, a determination may be made whether the component is to be subjected to a full heat treatment. If so (e.g., the “yes” path is taken out of block 934), flow may proceed from block 934 to block 938. Otherwise (e.g., the “no” path is taken out of block 934), flow may proceed from block 934 to block 942.
In block 938, a full heat treatment may be performed. A full heat treatment may (substantially) restore the component to a grade of service (e.g., a state/condition) comparable to the component as it existed following original manufacture (e.g., a so-called OEM component). The heat treatment applied in block 938 may include application of one or more of a solution heat treatment, a stabilization heat treatment, or a precipitation heat treatment. Application of a heat treatment in block 938 may eliminate some or all of any rolling residual stresses that may be present.
In block 942, a partial heat treatment may be performed. A partial heat treatment may restore the component to a grade of service that is appreciably less than that of an OEM component. The heat treatment that is applied in block 942 may reduce stress (e.g., residual stress) that may be present from, e.g., the deposition process (e.g., blocks 918 or 920), the solution heat treatment of block 910 and/or the cold working technique of block 922.
The heat treatment of block 938 or block 942 may recrystallize the last layer of deposited material that was cold worked.
In block 946, the component may be machined to specified dimensions. The machining of block 946 may be used to remove any excess filler material that may have been deposited in conjunction with, e.g., block 918. Referring to
In block 966, a determination may be made whether additional stress is needed. For example, the addition of compressive residual stress may improve/enhance the fatigue capability of the material of the component, such that the component may be utilized/operated for additional cycles/time before additional wear may be expected (or, more specifically, before the probability of additional wear exceeds a threshold). If additional residual stress is needed (e.g., the “yes” path is taken out of block 966), flow may proceed from block 966 to block 970. Otherwise (e.g., the “no” path is taken out of block 966), flow may proceed from block 966 to block 974.
In block 970, a (compressive) residual stress may be imparted on the component. As part of block 970, the component may be subjected to rolling, shot peen, burnishing, etc.
In block 974, the component may be returned to service. As part of block 974, the component may be installed on an engine.
The blocks of the method 900 described above are illustrative. In some embodiments, the blocks may execute in an order/sequence that is different from what is shown in
Aspects of the disclosure may provide a component that has a microstructure that is comparable (e.g., matched) to a microstructure of the component prior to restoration in accordance with an execution of the method 900. For example, a material of the component may have a first microstructure, and a second microstructure associated with filler material may be (substantially) matched to the first microstructure.
Aspects of the disclosure have been described in terms of illustrative embodiments thereof. Numerous other embodiments, modifications, and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. For example, one of ordinary skill in the art will appreciate that the steps described in conjunction with the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional in accordance with aspects of the disclosure. One or more features described in connection with a first embodiment may be combined with one or more features of one or more additional embodiments.
