Patent Application
20210197262
The present disclosure generally relates to manufactured components, and more particularly relates to systems and methods for additive manufacturing support removal and for surface finish enhancement of a manufactured component.
In the manufacture of certain components through additive manufacturing, one or more supports may be used as the component is being built to provide structural integrity during the manufacturing process. Once the component is built by additive manufacturing, the supports are typically removed prior to finalizing the component as the supports do not generally form a part of the finished component. In certain instances, due to the shape of the component, the supports may be contained within a blind cavity or regions that are difficult to access. In these situations, the removal of the supports is time consuming, costly and may require complicated machining techniques to separate the supports from the component.
Moreover, the formation of the component through additive manufacturing or other manufacturing processes may result in rough surfaces, due to the nature of the manufacturing process. In addition, in certain manufactured components, such as components cast with internal channels, the rough surfaces may cause debris or fine particles to accumulate within the internal channels during use. In certain instances, the manufactured component may undergo additional machining processes to smooth the rough surfaces. These additional machining processes may be time consuming and costly.
Accordingly, it is desirable to provide a system and method for removing supports from an additively manufactured component, which also provides surface finish enhancement during the same process. By removing the supports in the same process as the surface finish is enhanced, the manufacturing time for the component is reduced and manufacturing costs may be reduced. Further, it is desirable to provide a system and method for removing supports from an additively manufactured component, which reduces the need for complicated machining processes. In addition, it is desirable to provide a system and a method that enhances surface finish of manufactured components, such as cast components. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.
According to various embodiments, provided is a method for additive manufacturing support removal of an additive manufactured component. The method includes additively manufacturing a built component including at least one support having a thickness, and gaseous carburizing the built component and the at least one support to form a carburized component and at least one carburized support. Each of the carburized component and the at least one carburized support have a carburization layer with a predefined depth. The method includes removing the carburization layer to form the component devoid of the at least one carburized support.
The removing the carburization layer to form the component further includes etching the carburization layer in an etch system to remove the carburization layer and form the component devoid of the at least one carburized support. The etching the carburization layer in the etch system, further includes etching the carburization layer in an anodic etch system to form the component devoid of the at least one carburized support. The method also includes inserting a conformal cathode electrode into at least one of the carburized component and the at least one carburized support prior to the etching. The predefined depth is greater than the thickness of a rib associated with the at least one support. The additively manufacturing the built component further includes additively manufacturing a built component composed of at least 10% by weight chromium. The carburizing the built component and the at least one support to form the carburized component and the at least one carburized support further includes heating the built component and the at least one support in a carburization furnace that includes a carbon-containing gas at a temperature between 800 degrees Celsius to 1150 degrees Celsius to form the carburization layer with the predefined depth. The built component has a first surface finish and the component has a second surface finish that is less than the first surface finish, and the method further includes removing the carburization layer to form the component devoid of the at least one carburized support and with the second surface finish.
Also provided according to various embodiments, is a system for additive manufacturing support removal and for surface finish enhancement of a component. The system includes a source of an additively manufactured built component that includes at least one support, and a gaseous carburization system that carburizes the built component and the at least one support to form a carburized component and at least one carburized support. Each of the carburized component and the at least one carburized support have a carburization layer with a predefined depth. The system includes an etch system that removes the carburization layer to form the component devoid of the at least one carburized support.
The etch system is an anodic etch system that includes an electrolytic bath that receives the carburized component and the at least one support, a cathode electrode and an anode electrode, and the carburized component is the anode electrode. The cathode electrode is a conformal electrode that is insertable into at least one of the carburized component and the at least one carburized support prior to the etching. The conformal electrode includes a cathode electrode wire that is at least partially surrounded by an insulator. The insulator comprises a tube having a plurality of openings that expose the cathode electrode wire within the electrolytic bath. The insulator comprises a plurality of discrete insulators that are spaced apart along a length of the cathode electrode wire. The predefined depth is greater than a thickness of a rib associated with the at least one support. The built component is composed of at least 10% by weight chromium. The built component has a first surface finish and the component has a second surface finish that is less than the first surface finish.
Further provided is a method for surface finish enhancement of a manufactured component. The method includes providing a component that is composed of at least one corrosion resistant element, and the component includes at least one internal passage. The method includes gaseous carburizing the component to form a carburized component, with the carburized component having a carburization layer with a predefined depth. The method includes etching the carburized component in an anodic etch system to remove the carburization layer to enhance a surface finish of the component.
The method further includes inserting a conformal cathode electrode into the carburized component prior to the etching.
The exemplary embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
The following detailed description is merely exemplary in nature and is not intended to limit the application and uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. In addition, those skilled in the art will appreciate that embodiments of the present disclosure may be practiced in conjunction with any type of additively manufactured component that would benefit from having internal and/or external supports removed while enhancing surface finish, and the components described herein for a gas turbine engine are merely one exemplary embodiment according to the present disclosure. Moreover, the embodiments of the present disclosure may be practiced to improve a surface finish of component manufactured through other techniques, such as a cast component, for example. In addition, while the system and method are each described herein as being used with components for a gas turbine engine onboard a vehicle, such as a bus, motorcycle, train, motor vehicle, marine vessel, aircraft, rotorcraft and the like, the various teachings of the present disclosure can be used with a gas turbine engine on a stationary platform. Further, it should be noted that many alternative or additional functional relationships or physical connections may be present in an embodiment of the present disclosure. In addition, while the figures shown herein depict an example with certain arrangements of elements, additional intervening elements, devices, features, or components may be present in an actual embodiment. It should also be understood that the drawings are merely illustrative and may not be drawn to scale.
As used herein, the term “axial” refers to a direction that is generally parallel to or coincident with an axis of rotation, axis of symmetry, or centerline of a component or components. For example, in a cylinder or disc with a centerline and generally circular ends or opposing faces, the “axial” direction may refer to the direction that generally extends in parallel to the centerline between the opposite ends or faces. In certain instances, the term “axial” may be utilized with respect to components that are not cylindrical (or otherwise radially symmetric). For example, the “axial” direction for a rectangular housing containing a rotating shaft may be viewed as a direction that is generally parallel to or coincident with the rotational axis of the shaft. Furthermore, the term “radially” as used herein may refer to a direction or a relationship of components with respect to a line extending outward from a shared centerline, axis, or similar reference, for example in a plane of a cylinder or disc that is perpendicular to the centerline or axis. In certain instances, components may be viewed as “radially” aligned even though one or both of the components may not be cylindrical (or otherwise radially symmetric). Furthermore, the terms “axial” and “radial” (and any derivatives) may encompass directional relationships that are other than precisely aligned with (e.g., oblique to) the true axial and radial dimensions, provided the relationship is predominantly in the respective nominal axial or radial direction. As used herein, the term “transverse” denotes an axis that crosses another axis at an angle such that the axis and the other axis are neither substantially perpendicular nor substantially parallel.
With reference to
It should be noted that alternatively, the system 10 may be used with cast components, such as components formed through investment casting, etc. For example, a component associated with a gas turbine engine, such as a turbine blade, which may be cast from a metal or metal alloy. In this example, a component 18′ is cast by investment casting, for example, and may include internal cooling channels or passages. The internal cooling cavities or passages of the cast component 18′ may have undesirable high surface roughness, which may result in debris, such as dust or fine particles, becoming attached to or clogging the internal cooling channels or passages. The cast component 18′ may be transferred to the carburization system 14 and carburized to form a carburized component 22′. The depth of carburization associated with the carburized component 22′ is such that the carburization layer extends through a portion of the exposed internal and external surfaces of the cast component 18′. The carburized component 22′ is provided or transferred to the etch system 16. The etch system 16 removes the carburization layer, which results in a removal of the rough surface within the internal cooling channels or passages to form a resulting component 26′ with enhanced surface finish. In one example, the surface finish of the component 26′ is also improved by about 53% when compared to a surface finish of the cast component 18′, which reduces the likelihood of debris, such as dust or fine particles, from adhering to the internal cooling channels or passages. As used herein, the component 26′ is a component produced by casting that has an improved surface finish over the cast component 18′.
With continued reference to
In the example of DMLS, as is generally known, in order to produce the built component 18, a model, such as a design model, of the component may be defined in any suitable manner. For example, the model may be designed with computer aided design (CAD) software and may include three-dimensional (“3D”) numeric coordinates of the entire configuration of the turbine engine component including both external and internal surfaces. In one exemplary embodiment, the model may include a number of successive two-dimensional (“2D”) cross-sectional slices that together form the 3D component. The model of the component may include one or more supports to provide structural stability during the formation of the component. As is generally known, the speed, position, and other operating parameters of a laser beam of the additive manufacturing system 12 are controlled to selectively fuse the powder of a build material into larger structures by rapidly melting the powder particles that may melt or diffuse into the solid structure below, and subsequently, cool and re-solidify. As such, based on the control of the laser beam, each layer of build material may include unfused and fused build material that respectively corresponds to the cross-sectional passages and walls that form the built component 18.
Upon completion of a respective layer, a roller or wiper pushes a portion of a build material from a delivery device to form an additional layer of build material on a working plane of the fabrication device. The laser beam is movably supported relative to the component and is again controlled to selectively form another cross-sectional layer. In this example, as the laser forms the cross-sectional layers, the laser forms the supports 20. The supports 20 may be used to provide stability to curved or arcuate features of the component during the building of the component layer-by-layer. For example, with reference to
As shown in
Generally, the built component 18, and the supports 20, are composed of the same material, which in this example is a metal or metal alloy. In one example, the built component 18 and the supports 20 are composed of a metal or metal alloy containing chromium, including, but not limited to, Inconel 718, stainless steels, Inconel 625, Inconel 600, Rene 41, MA760, Nimonic 80A, Nimonic 105, Udimet 500, Udimet 700, Waspaloy, Rene 2000, MA760, MA758, FT750DC, Hastalloy X. Generally, the chromium concentration in the metal alloy is at least 10% by weight chromium. For example, Inconel 718 has between about 17%-21% by weight chromium, and stainless steel 316 has about 16%-18% by weight chromium. It should be noted that in certain instances, the built component 18 and the supports 20 may have a weight percentage of chromium, which is less than about 10%. With reference to
For example, the surface finish (Ra) of location A is about 392 microinches (μin.); the surface finish (Ra) of location B is about 337 microinches (μin.); the surface finish (Ra) of location C is about 323 microinches (μin.); the surface finish (Ra) of location D is about 429 microinches (μin.); the surface finish (Ra) of location E is about 473 microinches (μin.); the surface finish (Ra) of location F is about 496 microinches (μin.); the surface finish (Ra) of location G is about 353 microinches (μin.); and the surface finish (Ra) of location H is about 404 microinches (μin.). In this example, the average surface finish (Ra) is about 401 microinches
With reference back to
In the example of the cast component 18′, the cast component 18′ is formed via investment casting, for example, from a metal or metal alloy. In one example, the cast component 18′ is composed of a metal or metal alloy containing one or more corrosion resistant elements, including, but not limited to, single crystal super alloys, such as MAR-M247, NASAIR 100, CZMX-2, AMI, CMSX-4, CMSX-10, MC544, MC534, TMS-162, TMS-238, CMZX-8, CMSX-4 Plus. In the example of the cast component 18′ comprising MAR-M247, the corrosion resistant elements comprise chromium, molybdenum and tungsten. The cast component 18′ is provided or transferred to the carburization system 14. Generally, the cast component 18′ may be transferred to the carburization system 14 through any suitable technique, including, but not limited to, conveyer belt, robotic transfer, pallets, etc.
The carburization system 14 heats the built component 18, including the supports 20 or the cast component 18′, in the presence of at least one carbon containing gas to form a layer of carburization on the internal and external surfaces of the built component 18 and the supports 20, or the internal and external surfaces of the cast component 18′. In one example, the carburization system 14 includes a carburization furnace 40. The carburization furnace 40 heats the built component 18 and the supports 20, or the cast component 18′, at a temperature between about 800 degrees Celsius to about 1150 degrees Celsius in the presence of at least one a carbon containing gas. In this example, the carburization furnace 40 is a methane carburization furnace, which heats the built component 18 and the supports 20, or the cast component 18′, to a temperature between about 950 degrees Celsius to about 1050 degrees Celsius, in a mixture of hydrogen, methane, argon and nitrogen gases. The heating of the built component 18 and the supports 20, in the carbon containing gas, such as methane, reacts with the chromium to form a layer containing chromium carbide and the base metallic composition or the carburization layer 42 along the exposed surfaces (internal and external) to form the carburized component 22 and the carburized supports 24, including carburized ribs 25 of the carburized support 24. The heating of the cast component 18′ in the carbon containing gas, such as methane, reacts with the chromium, the tungsten and molybdenum to form a layer containing chromium carbide, tungsten carbide, molybdenum carbide and the base metallic composition or a carburization layer 42′ along the exposed surfaces (internal and external) to form the carburized component 22′.
In one example, the heating of the built component 18 and the supports 20, or the cast component 18′, is performed at a temperature of about 1050 degrees Celsius for about 2 hours to about 8 hours in a mixture of hydrogen, methane and argon (H2—CH4—Ar) gas, a mixture of argon methane (Ar—CH4) gas and hydrogen methane (H2—CH4) gas or a mixture of hydrogen, methane and nitrogen (H2—CH4—N2) gas to result in a carburization depth of about 200 micrometers. A volumetric flow rate of the carburization gas in the carburization furnace 40 may be about one liter (L) per minute (min). It should be noted that other carbon containing gases may be employed with the carburization furnace 40 to carburize the built component 18 and the supports 20, or the cast component 18′, including, but not limited to, ethylene, ethane, etc. In addition, it should be noted that the carburization of the built component 18 or the cast component 18′ by the carburization system 14 may take place in two runs, or that the carburization may be accomplished in a single run to achieve the same results. In addition, it should be noted that the length of time for the carburization of the built component 18 may be reduced based on the geometry of the supports 20. For example, if the wall thickness in the support 20 is reduced, less carburization is needed to reach the desired depth of carburization to remove the supports 20.
For example, with reference to
As a further example, with reference to
Once the carburized component 22 has undergone the carburization process such that the carburization layer 42 is formed to the predefined depth D, such as about 200 micrometers, on the carburized component 22 and the carburized supports 24, the carburized component 22, including the carburized supports 24, is provided or transferred to the etch system 16. Similarly, once the carburized component 22′ has undergone the carburization process such that the carburization layer 42′ is formed to the predefined depth D, such as about 200 micrometers, on the carburized component 22′, the carburized component 22′ is provided or transferred to the etch system 16. Generally, with reference back to
The etch system 16 removes the carburization layer 42 (
In this example, the etch system 16 includes a source of direct current 50, a cathode electrode or cathode 52 and an electrolytic bath 54. The source of direct current 50 may comprise any suitable source, including, but not limited to a battery, a direct current power supply, a direct current generator, etc. In one example, the source of direct current 50 supplies a voltage of about 500 millivolts (mV) to about 800 millivolts (mV), and a current of about 5 milliamps (ma) to about 300 milliamps (ma). The source of direct current 50 is electrically coupled to the cathode 52 and to the carburized component 22 and/or carburized supports 24. Thus, in this example, the carburized component 22 and/or carburized supports 24 form the anode electrode. In the example of the carburized component 22′, the source of direct current 50 is electrically coupled to the cathode 52 and to the carburized component 22′ such that the carburized component 22′ forms the anode electrode.
The source of direct current 50 may be electrically coupled to the cathode 52 and the carburized component 22, 22′ via any suitable technique, including, but not limited to, conductive wire, conductive clips, conductive plates, conductive foil, etc. The conductive wire, conductive clips, conductive plates and conductive foil may be composed of any suitable conductive material, including, but not limited to, stainless steel, superalloy (including, but not limited to, Inconel alloys, Hastalloys, Haynes Alloy 214, etc.), nichrome, etc. In one example, the source of direct current 50 is electrically coupled to a surface of the carburized component 22 and/or carburized supports 24, or to the carburized component 22′. It should be noted that as the voltage applied to the carburized component 22 and/or carburized supports 24, or the carburized component 22′, is controlled, the current level may be dependent upon a surface area of the carburized component 22 and carburized supports 24 or a surface area of the carburized component 22′, a distance between the anode and cathode electrodes, a temperature of the plating bath, a conductivity of the plating bath and other factors.
In this example, the voltage applied to the anode electrode (the carburized component 22 and/or carburized supports 24 or the carburized component 22′) and the cathode electrode is controlled. In this example, the voltage is controlled to maintain the voltage at precise voltages, such as a voltage less than about 1.0 volts (V). At low voltages, the etching is selective and only the carburized layer is etched. At voltages above 1.0 volts (V), in certain instances, the uncarburized metal or metal alloy of the carburized component 22 and/or carburized supports 24, or the carburized component 22′, may be etched, which is undesirable. In addition, the low voltage results in less oxide being formed on the anode electrode. In one example, an initial or starting voltage of 0.8 volts (V) is applied until no current flows at 0.8 volts (V). Then, the voltage was reduced in 0.1 volt (V) increments over a period to time, for example 70 hours, until no current flows at 0.1 volts (V). At each voltage increment (0.8 volts (V), 0.7 volts (V), 0.6 volts (V), etc. to 0.1 volts (V)), the voltage is applied at that particular voltage until no current flows and the etch process self-terminates. Upon self-termination at the particular voltage, the voltage is reduced by the next 0.1 voltage (V) increment, until 0.1 volts (V) is applied and no current flows at 0.1 volts (V). By incrementally reducing the applied voltage after self-termination at a particular voltage until the etching self terminates at 0.1 volts (V), additional etching of the carburized component 22 and/or carburized supports 24, or the carburized component 22′, is achieved, which ensures removal of the carburization layer 42, 42′. Stated another way, the gradual reduction in the applied voltage to the cathode and the anode ensures a substantially complete removal of the carburization layer 42, 42′ (less than about 7% of the carburization layer 42, 42′ remaining). By applying the voltage incrementally, the etching continues without passivating until a high chromium concentration is reached, which is at the surface of the component 26, 26′. By incrementally decreasing voltage, the etch system 16 etches more deeply into the carburization layer 42, 42′. Generally, as the etching progresses through the carburization layer 42, 42′, the amount of free chromium increases. The anodic potential oxidizes (passivates) the chromium in the carburized component 22, or carburized component 22′, until a high chromium concentration is reached at which point the etching self terminates.
The cathode 52 is positioned within the electrolytic bath 54 so as to be spaced apart from the carburized component 22 and carburized supports 24 or the carburized component 24′. The cathode 52 may have any desired shape to facilitate the etching of the carburized component 22 and carburized supports 24, or the carburized component 24′. In one example, the cathode 52 may comprise a flat plate, a ring or may be conformal to the shape of the carburized component 22 and carburized supports 24, or the carburized component 24′. In the example of a flat plate or ring, the cathode 52 may be composed of a suitable metal or metal alloy, including, but not limited to a Haynes Alloy 214, which may be stamped, cast, forged, etc. In the example of a conformal cathode, with reference to
The conformal cathode 52a includes a cathode electrode wire or cathode wire 60 and at least one insulator 62. The cathode wire 60 comprises any suitable electrically conductive wire, including, but not limited to, a Haynes Alloy 214 wire, etc. In this example, the at least one insulator 62 comprises a plurality of insulators 62a-62d, which are spaced apart along a length of the cathode wire 60. Generally, each of the plurality of insulators 62a-62d have a thickness that inhibits or prevents the contact between the cathode wire 60 and the carburized component 22 and/or carburized supports 24, or the carburized component 22′. Thus, the insulators 62a-62d ensure that the cathode wire 60 remains spaced apart from the carburized component 22 and/or carburized supports 24, or the carburized support 22′, during the insertion of the conformal cathode 52a into the carburized component 22 and/or carburized supports 24, or the carburized component 22′. Each of the insulators 62a-62d are composed of a suitable electrically insulating material, including, but not limited to, a polymer-based material, Tygon®, etc. Tygon® is commercially available from Saint-Gobain Corporation of Malvern, Pa. In this example, the carburized component 22 is shown with one or more access openings 64 for insertion of the conformal cathode 52a; however, it should be understood that the carburized component 22 and/or carburized supports 24 may be built, through the additive manufacturing system 12 (
It should be noted that while the conformal cathode 52a is shown herein as comprising a plurality of separate and discrete insulators 62a-62d, the conformal cathode 52a may be constructed differently to insulate the cathode wire 60 during insertion into the carburized component 22 and/or carburized supports 24, or the carburized component 22′. For example, with reference to
In addition, it should be noted that while the conformal cathode 52a is shown herein as comprising a plurality of separate and discrete insulators 62a-62d, the conformal cathode 52a may be constructed differently to insulate the cathode wire 60 during insertion into the carburized component 22 and/or carburized supports 24, or the carburized component 22′. For example, the conformal cathode 52a may include a plurality of separate and discrete insulators that extend outwardly from the cathode wire 60 like a bristle on a brush, such that the insulators support and center the cathode wire 60 within a tube or cavity of the carburized component 22 and/or carburized supports 24, or the carburized component 22′, while inhibiting a shorting between the cathode wire 60 and the carburized component 22 and/or carburized supports 24, or the carburized component 22′. Thus, in this example, the conformal cathode 52a is in the form of a test tube brush, in which the cathode wire 60 extends along a body of the conformal cathode 52a, and the insulators extend outwardly away, like bristles, about the cathode wire 60.
With reference to
In certain embodiments, the tank 70 may include a filter 74 and/or an agitator 76. The filter 74 and the agitator 76 may be combined into a single unit, and at least partially inserted into the tank 70. The filter 74 may remove particles from the electrolytic solution 72, and the agitator 76 may stir the electrolytic solution 72 to enhance the etching of the carburized component 22 and/or carburized supports 24, or the carburized component 22′.
The electrolytic solution 72 drives the etching of the carburized component 22 and/or carburized supports 24, or the carburized component 22′, and is contained within the tank 70. In one example, the electrolytic solution 72 is composed of potassium chloride (KCL), nitric acid (HNO3), tartaric acid, citric acid, sodium citrate acid and combinations thereof. In one example, the electrolytic solution 72 comprises about 0.10 molar potassium chloride to about 0.60 molar potassium chloride and about 0.050 molar nitric acid to about 0.20 molar nitric acid dissolved in water. In another example, the electrolytic solution 72 may include organic acids, such as sodium citrate acid, citric acid or tartaric acid, which may have a concentration of about 0.1 molar organic acid to about 1.0 molar organic acid dissolved in water. The cathode 52 and the carburized component 22 and/or carburized supports 24, or the carburized component 22′, are positioned within the tank 70 so as to be immersed within the electrolytic solution 72. In one example, the electrolytic solution 72 has a pH of about 0.5 to about 9.0, and in the example of the electrolytic solution 72 including nitric acid, the pH is about 0.5 to about 1.0. In the example of sodium citrate acid, the pH may be neutral. Generally, the electrolytic solution 72 may electroplate or regenerate deposits on the cathode 52 (electrowinning), which may prolong the life of the cathode 52. In addition, the electrolytic solution 72 is environmentally friendly and lasts for a longer duration given the regenerative nature of the electrolytic solution 72.
Once the carburized component 22 and/or carburized supports 24, or the carburized component 22′, are electrically coupled to the source of direct current 50 and the cathode 52 is electrically coupled to the source of direct current 50, the carburized component 22 and/or carburized supports 24, or the carburized component 22′, and the cathode 52 are positioned within the electrolytic solution 72 contained within the tank 70. It should be noted that while generally an entirety of the carburized component 22 and carburized supports 24, or the carburized component 22′, are submerged within the electrolytic solution 72, a portion of the cathode 52 may be submerged within the electrolytic solution 72. An electrochemical reaction occurs between the cathode 52, anode (carburized component 22 and carburized supports 24 or carburized component 22′) and the electrolytic solution 72, which causes the corrosion of the respective carburization layer 42, 42′. The electrochemical reaction continues until the carburization layer 42 is substantially or completely removed to the internal surface and external surface 34 of the built component 18 (
In this regard, once the base material, Inconel 718 in the example of the carburized component 22 and carburized supports 24 or MAR-M247 in the example of the carburized component 22′, is exposed by the etching of the carburization layer 42, 42′, the etching terminates as the base material, for example, Inconel 718 or MAR-M247, is corrosion resistant and is not susceptible to etching by the etch system 16. Stated another way, the carburization layer 42 formed on the internal surface and the external surface 34 of the carburized component 22 (
In addition, the removal of the carburization layer 42, 42′ by the etch system 16 also improves a surface finish of the resulting component 26, 26′. In this regard, with reference to
For example, the surface finish (Ra) of location A after etching is about 156 microinches (μin.); the surface finish (Ra) of location B after etching is about 189 microinches (μin.); the surface finish (Ra) of location C after etching is about 217 microinches (μin.); the surface finish (Ra) of location D after etching is about 293 microinches (μin.); the surface finish (Ra) of location E after etching is about 146 microinches (μin.); the surface finish (Ra) of location F after etching is about 152 microinches (μin.); the surface finish (Ra) of location G after etching is about 131 microinches (μin.); and the surface finish (Ra) of location H after etching is about 210 microinches (μin.). In this example, the average surface finish (Ra) of the built component 18 after etching is about 187 microinches (μin.). Thus, in this example, the removal of the carburization layer 42 by the etch system 16 reduces the surface finish (Ra) of the built component 18 by about 53%. Accordingly, the built component 18 (
It should be noted that the use of the etch system 16 also facilitates the removal of cling-on or other loose feedstock particles produced during the additive manufacturing of the built component 18. In this regard, as the cling-on or loosely attached particles undergo carburization with the built component 18, due to the particle size of the cling-on or loose feedstock particles, the cling-on or loosely attached particles become carburized substantially throughout an entirety of the cling-on or loose feedstock particle. As the cling-on or loosely attached particle is carburized substantially completely, the etching of the carburized component 22 removes the cling on or loosely attached particles. The removal of the cling-on or loosely attached particles eliminates the need for additional machining of the component 26 to remove these types of particles. With reference to
Once the etching of the carburized component 22 and the carburized supports 24 by the etch system 16 has self-terminated, the component 26, with the supports completely removed, is available for further processing. For example, the removal of the carburization layer 42 along with the carburized supports 24 enables the component 26 to undergo electropolishing after etching. Given the surface finish improvement provided by the etch system 16, electropolishing the component 26 may result in a mirror finish for the component 26 without requiring additional machining or processing steps. Similarly, Once the etching of the carburized component 22′ by the etch system 16 has self-terminated, the component 26′ is also available for further processing.
It should be noted that the system 10 and method 200, 250 (
In one example, with reference to
The method begins at 202. At 204, the additive manufacturing system 12 builds the built component 18 to include the one or more supports 20. At 206, the built component 18 is carburized in the carburization system 14 to form the carburization layer 42 on the exposed surfaces of the built component 18 and the supports 20 to the predefined depth D. Generally, the built component 18 is carburized to the predefined depth D such that an entirety of the supports 20 are carburized. In one example, the built component 18 and the supports 20 are carburized such that the predefined depth D defines an area of overlap between the exposed surfaces of the supports 20, ensuring the ribs 21 associated with the supports 20 are fully carburized. Generally, the predefined depth D is about 200 micrometers. At 208, optionally, the conformal cathode 52a may be inserted into the carburized component 22 and/or the carburized supports 24 to assist in the etching of the carburized component 22 and/or the carburized supports 24. At 210, the carburization layer 42 is removed with the etch system 16 to remove the carburized supports 24 completely and enhance the surface finish of the external surface 34 of the resulting component 26. The etching self-terminates once the carburization layer 42 is removed and the method ends at 212.
In one example, with reference to
The method begins at 252. At 252, the cast component 18′ is formed, via investment casting, for example. At 256, the cast component 18′ is carburized in the carburization system 14 to form the carburization layer 42′ on the exposed surfaces (internal and external) of the cast component 18′ to the predefined depth D. Generally, the predefined depth D is about 200 micrometers. At 258, optionally, the conformal cathode 52a may be inserted into the carburized component 22′ to assist in the etching of the carburized component 22′. At 260, the carburization layer 42′ is removed with the etch system 16 to enhance the surface finish of the exposed surfaces of the resulting component 26′. The etching self-terminates once the carburization layer 42′ is removed and the method ends at 262.
Thus, the system 10 and the method 200 of the present disclosure provide additive manufacturing support removal and surface finish enhancement of the component 26. The system 10 and the method 250 of the present disclosure provide surface finish enhancement of the component 26′, which reduces a likelihood of debris or fine dust particles adhering to or clogging internal passages defined in the component 26′. By carburizing the built component 18 and etching the carburized component 22 and the carburized supports 24, the supports 20 are completely removed from the component 26 without requiring labor intensive chemical slurries, the release of toxic by-products or machining. The system 10 and method 200 also enable the removal of supports 20 that are formed within the blind cavities or internally within the built component 18 without requiring complex machining. Thus, the system 10 and the method 200 enable the removal of supports 20 within the built component 18 that are not within a light of sight. In addition, the use of the conformal cathode 52a increases the rate of the etching by the etch system 16 by enabling the cathode to be positioned within the carburized component 22 and/or carburized supports 24, or the carburized component 24′. Moreover, by carburizing and etching the built component 18, or the cast component 18′, the surface finish of the component 26, or the component 26′, is improved and loosely attached particles are removed without requiring further machining. Thus, the system 10 and the method 200, 250 reduce manufacturing complexity, manufacturing cost and manufacturing time associated with additive manufactured or cast components.
With reference to
In this example, the support 20 was thicker than 200 micrometers (μm), and thus, additional time was needed to fully carburize the support 20. The support 20 was about 200 micrometers (μm) to 250 micrometers (μm) thick, and a photographic detail cross-sectional view of the support 20 is shown in
Once carburized (as shown in
In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Numerical ordinals such as “first,” “second,” “third,” etc. simply denote different singles of a plurality and do not imply any order or sequence unless specifically defined by the claim language. The sequence of the text in any of the claims does not imply that process steps must be performed in a temporal or logical order according to such sequence unless it is specifically defined by the language of the claim. The process steps may be interchanged in any order without departing from the scope of the invention as long as such an interchange does not contradict the claim language and is not logically nonsensical.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof.
