Electrolytic machining method and system

Abstract

To provide methods and systems of electrochemical machining.SOLUTION: The method may include applying a first potential to a tool electrode of an electrochemical machining system to generate a primary electric field. The electrochemical machining system may include a workpiece opposite to the tool electrode, at least one bias electrode, and at least one fluid delivery channel within the at least one bias electrode. The method may further include applying at least one second potential to the at least one bias electrode. The method may further include delivering a charged electrolyte solution through the at least one fluid delivery channel into the electrolyte solution. Applying at least one second potential and delivering the charged electrolyte solution generate at least one secondary electric field adjacent to the primary electric field and quenches at least one location of the primary electric field.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Application No. 17 / 843,254, filed June 17, 2022, which is incorporated herein in its entirety.

[0002] The field of the disclosure relates generally to electrochemical machining, and more particularly to methods and systems for performing electrochemical machining. [Background technology]

[0003] Electrochemical machining (ECM) is a process that removes conductive material, such as metallic material, through an electrochemical process. ECM is typically used for machining (including machining or finishing) workpieces composed of conductive materials. ECM typically provides desirable shape control and smooth surface finishes in the manufacture of components, including bladed disks and other components for gas turbines, jet engines, power generation, etc. Summary of the Invention [Means for solving the problem]

[0004] A full and enabling disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in this specification, which makes reference to the accompanying drawings. [Brief explanation of the drawings]

[0005] [Figure 1] 1 is a schematic diagram of an exemplary electrochemical machining system including a tool electrode and at least one bias electrode. [Figure 2] FIG. 2 is a schematic diagram of another exemplary electrochemical machining system according to the present disclosure. [Figure 3] 2 is a bottom perspective view of the tool electrode and at least one bias electrode of FIG. 1. [Figure 4]1 is a schematic diagram of a computing system including computing devices, one of which may function the same as or similar to a controller of the present disclosure. [Figure 5] 1 is a flowchart of an electrochemical machining method according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0006] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the present disclosure.

[0007] Reference will now be made in detail to the embodiments of the present disclosure, at least one example of which is illustrated in the drawings. Each example is provided by way of explanation of the disclosure, and not as a limitation of the disclosure. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope of the disclosure. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Accordingly, it is intended that the present disclosure cover all such modifications and variations as come within the scope of the appended claims and their equivalents.

[0008] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, unless specifically stated otherwise, all embodiments described herein should be considered exemplary.

[0009] Terms such as "coupled," "fixed," and "attached," unless otherwise specified herein, refer to both direct coupling, fixing, or attachment, and indirect coupling, fixing, or attachment through at least one intermediate component or mechanism.

[0010] As used herein, the terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and do not imply any position or importance of the individual components.

[0011] In the following specification and claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. As used herein, the term "or" does not mean exclusive and refers to the presence of at least one of the referenced elements, unless the context clearly dictates otherwise, and includes the presence of any combination of the referenced elements.

[0012] As used herein, the term "quench" refers to a potential gradient within a specific region of an electric field that is below the standard potential, allowing for electrochemical oxidation of a workpiece. As used herein, the term "location" refers to a specific region of the electric field that is potential quenched. While the strength of the electric field cannot be measured directly, the effect of increasing or decreasing the field strength within a specific location of the electric field can be readily observed, as described herein, allowing for a determination of whether the electric field is potential quenched at a particular location.

[0013] As used herein, the term "stray current attack" refers to the oxidation of a previously electrochemically machined finished part adjacent to a workpiece during ECM of the workpiece. Stray current attack is determined to have occurred when there is evidence of additional material removal and surface pitting of the adjacent finished component as a result of ECM of the workpiece.

[0014] During the ECM process, conductive material is oxidized from the workpiece using an electrical potential applied to a tool electrode opposite the workpiece, causing current to flow at a controlled rate through an electrolyte solution located between the tool electrode and the workpiece. The workpiece acts as the anode and is separated by an electrode gap from the tool electrode, which acts as the cathode. The electrolyte solution (usually a saline solution in water) flows through the electrode gap and flushes the oxidized material from the workpiece. As the tool electrode moves toward the workpiece to maintain the controlled electrode gap, the workpiece is machined to the complementary shape of the tool electrode.

[0015] ECM is particularly useful for hard metals and alloys that are difficult to machine using traditional methods. For example, nickel-based alloys may be machined using ECM to produce a variety of components, such as bladed disks. When ECM is used to manufacture bladed disks, each airfoil is electrochemically machined onto the bladed disk one at a time. Specifically, once a single completed airfoil is electrochemically machined onto the bladed disk, the bladed disk rotates to perform ECM on the next airfoil adjacent to the completed airfoil. This process is repeated until the bladed disk has the required number of airfoils.

[0016] However, fabricating bladed disks using ECM has proven challenging when using more complex metals and alloys, such as titanium-based alloys. Specifically, when machining bladed disks containing more complex alloys using ECM, stray currents tend to flow from the area of ​​the airfoil being machined to adjacent, previously completed airfoils on the bladed disk. Stray currents can damage the smooth surface finish of the previously finished airfoil, resulting in bladed disks containing airfoils with incompatible shapes or finishes, potentially compromising part performance. This observation of stray current corrosion is not limited to ECM on compressor bladed disks, but can generally be observed in any ECM application when the component has dense features and complex metals or alloys are used.

[0017] Therefore, a need exists to potential suppress the primary electric field generated by the ECM process at strategic locations to combat stray current corrosion of the finished part adjacent the workpiece.

[0018] Embodiments of the present disclosure provide an ECM process for preventing stray current corrosion of a finished part adjacent to a workpiece. The ECM process generally involves selectively potential-suppressing a primary electric field location generated between a tool electrode and a workpiece. The primary electric field location can be selectively potential-suppressed using a combination of biased anodic protection and charged electrolyte delivery. Selectively potential-suppressing the primary electric field location minimizes stray current corrosion and oxidation rates of a finished part adjacent to a workpiece that has already been subjected to ECM. In this regard, the methods and systems described herein utilize a combination of biased anodic protection and charged electrolyte flow that can be used in an electrochemical machining system to strategically modify the electric field generated during ECM at at least one location within the electrolyte solution to combat stray current corrosion of a finished part adjacent to the workpiece. Embodiments of the present disclosure provide the ability to more effectively manage stray currents and more precisely control the shape of the workpiece.

[0019] 1 and 2 each show a schematic diagram of an exemplary electrochemical machining system 100 including a tool electrode 120 and at least one bias electrode 140. Specifically, the electrochemical machining system 100 includes the tool electrode 120 configured to generate a primary electric field 200 between the tool electrode 120 and a workpiece 130 opposite the tool electrode 120. The at least one bias electrode 140 is disposed adjacent to the tool electrode 120. Each of the at least one bias electrode 140 includes at least one fluid delivery channel 144. The at least one bias electrode 140 is configured to generate at least one secondary electric field 210 adjacent to the primary electric field 200.

[0020] In one embodiment, at least one biased electrode 140 is strategically positioned in an area of ​​the electrochemical machining system 100 where stray current corrosion is expected. For example, in the exemplary embodiment of FIGS. 1 and 2, stray current corrosion may be expected on the finished part 150 adjacent to the workpiece 130 during ECM operations. Specifically, without the biased anode protection and charged electrolyte delivery of the present disclosure, the primary electric field 200 generated between the tool electrode 120 and the workpiece 130 is expected to be constrained only by areas where the primary electric field 200 naturally dissipates, allowing stray currents to flow freely from the primary electric field 200 to the finished part 150, if naturally possible. 1 and 2, the at least one biased electrode 140 is preferably positioned adjacent the tool electrode 120 and opposite the workpiece 130 to allow charged electrolyte solution 142 to be delivered through at least one fluid delivery channel 144 and through at least one nozzle 141 of the at least one biased electrode 140 into the electrode gap 180 of the electrochemical machining system 100. Thus, the at least one biased electrode 140 inhibits stray current corrosion of the finished part 150 adjacent the workpiece 130.

[0021] The workpiece 130 and the at least one bias electrode 140 may comprise any metallic material suitable for ECM. In one embodiment, the workpiece 130 and the at least one bias electrode 140 may each comprise a metallic material that is unique to each other. Alternatively, the workpiece 130 and the at least one bias electrode 140 may comprise the same metallic material as each other.

[0022] For example, in one embodiment, the workpiece 130 and the at least one bias electrode 140 may comprise a metallic material. In further embodiments, the metallic material may comprise a pure metal or a metal alloy. Pure metals may include titanium, niobium, nickel, zirconium, palladium, platinum, aluminum, chromium, manganese, cobalt, molybdenum, hafnium, tungsten, or a combination thereof. Alloys may include superalloys, such as titanium-based alloys, niobium-based alloys, nickel-based alloys, zirconium-based alloys, palladium-based alloys, platinum-based alloys, aluminum-based alloys, chromium-based alloys, manganese-based alloys, cobalt-based alloys, molybdenum-based alloys, hafnium-based alloys, tungsten-based alloys, or a combination thereof. However, other metallic materials may also be used.

[0023] 1 and 2, the exemplary electrochemical machining system 100 includes at least one spacer 160 disposed between the at least one bias electrode 140 and the tool electrode 120. The at least one spacer includes a non-conductive material that electrically insulates the tool electrode 120 from the at least one bias electrode 140. Thus, at least one secondary electric field 210 can be generated adjacent to the primary electric field 200. For example, the at least one spacer 160 may include a glass-fiber reinforced non-conductive material, such as a fluoropolymer.

[0024] In one embodiment, the at least one spacer 160 may have a thickness of 100 micrometers to 2500 micrometers, such as 350 micrometers to 2000 micrometers, for example 500 micrometers to 1500 micrometers, hi one embodiment, the at least one spacer 160 may have a thickness of 750 micrometers to 1000 micrometers.

[0025] The workpiece 130 is separated from the tool electrode 120 by an electrode gap 180, with an electrolyte solution 190 interposed between the tool electrode 120 and the workpiece 130. The electrode gap 180 can be changed by moving the tool electrode 120, the workpiece 130, or a combination thereof.

[0026] The workpiece 130, the tool electrode 120, and the at least one bias electrode 140 of the electrochemical machining system 100 may be electrically connected in at least one electrical circuit. In an exemplary embodiment, as shown in FIG. 1, the workpiece 130, the tool electrode 120, and the at least one bias electrode 140 are electrically connected in a circuit. Furthermore, each of the workpiece 130, the tool electrode 120, and the at least one bias electrode 140 may be electrically connected in series or parallel to one another. In an exemplary embodiment, as shown in FIG. 1, the electrochemical machining system 100 includes at least one bias electrode 140 electrically connected in series with the tool electrode 120 and the workpiece 130. In one embodiment, as shown in FIG. 1, the electrochemical machining system may include a single power supply 170. Alternatively, as shown in FIG. 2, which illustrates a front schematic view of another exemplary electrochemical machining system 100, the electrochemical machining system 100 may be electrically connected to a first power supply 171 and at least one second power supply 172.

[0027] 1 and 2, the electrochemical machining system 100 further includes an electrolyte source 143 configured to deliver a charged electrolyte solution 142 to the at least one fluid delivery channel 144. The electrolyte source 143 may contain an electrolyte solution and be in fluid communication with the at least one bias electrode 140. The electrolyte source 143 may supply the electrolyte solution to the at least one bias electrode 140 using any suitable means known in the art. For example, a conventional pump (not shown) may be used to move the electrolyte solution from the electrolyte source 143 to the at least one bias electrode 140.

[0028] The charged electrolyte solution 142, along with the electrolyte solution 190 in the electrode gap 180, may include any suitable electrolyte, such as a base, an acid, or an ionic liquid. In some embodiments, the electrolyte solution 190 includes an ionic salt, a binary acid, an organic acid, a deep eutectic, a molten salt, or a combination thereof. The charged electrolyte solution 142, the electrolyte solution 190, or both may be an aqueous electrolyte, such as an aqueous salt electrolyte including water and at least one salt. In one embodiment, the charged electrolyte solution 142, the electrolyte solution 190, or both may include an aqueous salt electrolyte including sodium nitrate, sodium chloride, sodium bromide, sodium hydroxide, perchloric acid, phosphoric acid, or a combination thereof. In some embodiments, the charged electrolyte solution 142, the electrolyte solution 190, or both may comprise 10% to 30% sodium nitrate by weight. For example, an electrolyte solution including 20% ​​sodium nitrate by weight may be used to electrochemically process a nickel-based alloy such as Inconel 718. Additionally, the charged electrolyte solution 142, the electrolyte solution 190, or both, are generally pH adjusted depending on the material being electrochemically processed. For example, the electrolyte may be pH adjusted to a pH of 5 to 10. It will be appreciated that other aqueous electrolytes may also be used with the techniques of the present disclosure.

[0029] 1 and 2, the electrochemical machining system 100 may further include a controller 112, a power supply 170, and an actuator 113. The controller 112 may be operably connected to the power supply 170 to adjust the voltage of the first potential and at least one second potential as desired. The controller 112 may further be operably connected to the actuator 113 to adjust the position of the tool electrode 120 and / or the workpiece 130 during the ECM process. As used herein, the phrase "operably connected" should be understood to mean that the respective components may be directly connected (e.g., mechanically or electrically) or may be connected via other components.

[0030] 1 as separate units, they may be a combined unit. Additionally, in some embodiments, the controller 112 may be configured and function in the same or similar manner as one of the computing devices 402 of the computing system 400 of FIG.

[0031] 3, a bottom perspective view of the tool electrode 120 and at least one bias electrode 140 of FIGS. 1 and 2 is shown, where the at least one bias electrode 140 can be positioned relative to the tool electrode 120 in a variety of ways. For example, as shown in FIG. 3, the bottom surface of the tool electrode 120 can have a generally circular shape, with each of the at least one bias electrode 140 positioned equidistant from one another radially around the tool electrode 120. However, other configurations can be used as desired, as the configuration of the tool electrode 120 and the at least one bias electrode 140 will depend at least on the shape of the workpiece 130 and the location where stray current corrosion is intended to be minimized.

[0032] 4 provides an exemplary computing system 400 according to an exemplary embodiment of the present subject matter. The controller 112 described herein includes various components and can perform various functions of at least one computing device 402 of the computing system 400, as described below.

[0033] 4, computing system 400 may include at least one computing device 402. Computing device 402 may include at least one processor 404 and at least one memory device 406. The at least one processor 404 may include any suitable processing device, such as a microprocessor, a microcontroller, an integrated circuit, a logic device, and / or other suitable processing device. The at least one memory device 406 may include at least one computer-readable medium, including, but not limited to, a non-transitory computer-readable medium, RAM, ROM, a hard drive, a flash drive, and / or other memory device.

[0034] The at least one memory device 406 may store information accessible by the at least one processor 404, including computer-readable instructions 408 that may be executed by the at least one processor 404. The instructions 408 may be any set of instructions that, when executed by the at least one processor 404, cause the at least one processor 404 to perform an operation, such as any of the operations described herein. For example, the methods provided herein may be implemented in whole or in part by the computing system 400. The instructions 408 may be software written in any suitable programming language or may be implemented in hardware. Additionally and / or alternatively, the instructions 408 may execute in logically and / or virtually separate threads on the processor 404. The memory device 406 may further store data 410 that may be accessed by the processor 404. For example, the data 410 may include models, databases, etc.

[0035] The computing device 402 may also include a network interface 412 used, for example, to communicate (e.g., over a network) with other components of the electrochemical machining system 100. The network interface 412 may include any suitable components for interfacing with at least one network, including, for example, a transmitter, a receiver, a port, an antenna, and / or other suitable components.

[0036] In another embodiment, a method 700 for electrochemically machining a workpiece is generally provided, as shown in the flowchart of FIG. 5 . The method includes applying a first potential to a tool electrode of an electrochemical machining system to generate a primary electric field 710. The electrochemical machining system includes a workpiece opposite the tool electrode, at least one bias electrode, and at least one fluid delivery channel within the at least one bias electrode. The primary electric field is generated in an electrolyte solution between the tool electrode and the workpiece. The method further includes applying at least one second potential to the at least one bias electrode 720. The method further includes delivering a charged electrolyte solution through the at least one fluid delivery channel 730 into the electrolyte solution, where applying the at least one second potential and delivering the charged electrolyte solution generate at least one secondary electric field adjacent to the primary electric field, potential suppressing at least one location of the primary electric field. Biased anode protection works in combination with charged electrolyte delivery to achieve robust operation for electrochemically machining complex shapes using difficult-to-machine materials while combating stray current corrosion of adjacent finished surfaces.

[0037] In certain embodiments, delivering a charged electrolyte solution through at least one fluid delivery channel in at least one biased electrode, in combination with applying at least one second potential to the at least one biased electrode, provides the ability to locally modify the primary electric field and affect the oxidation rate of local materials, including the workpiece and adjacent finished parts. In certain embodiments, the combination of strategic placement of at least one biased electrode and charged electrolyte delivery through at least one fluid channel allows the primary electric field to be potential-suppressed in strategic locations and generally coupled to the actual site of electrochemical machining. Thus, a method is generally provided for more precisely controlling the primary electric field to combat stray current corrosion of the primary field on adjacent finished parts.

[0038] During operation, the workpiece 130 functions as an anode and the tool electrode 120 functions as a cathode, generating a primary electric field 200 between the workpiece 130 and the tool electrode 120. Additionally, at least one bias electrode 140 may function as an anode and the tool electrode 120 may function as a cathode, generating at least one secondary electric field 210 adjacent to the primary electric field 200 between at least one each bias electrode 140 and the tool electrode 120.

[0039] As discussed, a single power supply 170 can be electrically connected to the electrochemical machining system 100. In one embodiment, the method can include applying a first potential and at least one second potential to the electrochemical machining system 100 using the single power supply 170.

[0040] Additionally, in another embodiment, the method may include applying a first electric potential to the electrochemical machining system 100 using a first power supply 171 and applying at least one second electric potential to the electrochemical machining system 100 using at least one second power supply 172. Applying the first electric potential to the electrochemical machining system 100 may generate a primary electric field 200, while applying the at least one second electric potential to the electrochemical machining system 100 may generate at least one secondary electric field 210 adjacent to the primary electric field 200.

[0041] Each of the at least one second potentials may be at a unique voltage relative to one another. That is, the at least one second potential may include two or more second potentials that are at unique voltages relative to one another. This allows precise control of the oxidation of the workpiece 130 at selected locations on the workpiece 130, since each of the at least one secondary electric field 210 may be generated to remove material from the workpiece 130 at a unique oxidation rate. Alternatively, the at least two or more second potentials may be at the same voltage.

[0042] In one embodiment, the first potential applied to the electrochemical machining system 100 may be a first DC potential between 5 volts and 50 volts, e.g., between 5 volts and 35 volts. In one embodiment, the at least one second potential applied to the electrochemical machining system 100 may be at least one second DC potential between 1 volt and 50 volts, e.g., between 1 volt and 35 volts, e.g., between 1 volt and 10 volts.

[0043] In one embodiment, the method may include applying a first potential to the electrochemical machining system 100, where the first potential is a first pulsed potential. Similarly, the method may include applying at least one second potential to the electrochemical machining system 100, where the at least one second potential applied to the electrochemical machining system 100 is at least one second pulsed potential. Specifically, the power supply 170 may be configured to provide the first pulsed potential, the at least one second pulsed potential, or a combination thereof in the form of a pulsed potential (more specifically, a bipolar pulsed potential). In one embodiment, the application of the first pulsed potential to the tool electrode 120 electrochemically removes a predetermined amount of material from the workpiece 130, while the application of the at least one second pulsed potential to the at least one bias electrode 140 generates at least one secondary electric field 210.

[0044] As used herein, the term "average potential" refers to the average of the off-time potential and the on-time potential of each pulse potential. In some embodiments, the average potential of the first pulse potential may be in the range of 1 to 5 volts. Additionally, the average potential of at least one second pulse potential may be in the range of 1 to 5 volts.

[0045] In one embodiment, the power supply 170 may include a bipolar power supply and may be configured to perform pulse train control. In another embodiment, the controller 112 may be configured to adjust the pulse duration, frequency, and voltage of the first pulsed potential applied to the tool electrode 120 and the workpiece 130, and the pulse duration, frequency, and voltage of the second pulsed potential applied to the tool electrode 120 and the at least one bias electrode 140, as needed.

[0046] For example, the pulse duration of the first pulse potential, the at least one second pulse potential, or a combination thereof may be from 10 nanoseconds to 1000 microseconds, e.g., from 10 nanoseconds to 50 microseconds. Further, in one embodiment, the voltage applied to the first pulse potential, the at least one second pulse potential, or a combination thereof may be from 10 volts to 50 volts, e.g., from 15 volts to 25 volts.

[0047] Additionally, in some embodiments, the method includes controlling the distance between the tool electrode 120 and the workpiece 130 (i.e., the length of the electrode gap 180) to be greater than 0.05 millimeters, for example, greater than 0.1 millimeters. In some embodiments, the method includes controlling the distance between the tool electrode 120 and the workpiece 130 to be between 0.1 millimeters and 2 millimeters, for example, between 0.5 millimeters and 1.5 millimeters.

[0048] In one embodiment, the method includes delivering a charged electrolyte solution through at least one fluid delivery channel into the electrolyte solution step 730. Specifically, the charged electrolyte solution is delivered from an electrolyte source through at least one fluid delivery channel in the at least one bias electrode to the electrode gap.

[0049] In an exemplary embodiment, a power source may be electrically connected to the at least one bias electrode when the electrolyte solution is delivered from the electrolyte source to the at least one bias electrode. The electrolyte solution transported from the electrolyte source may be charged by at least one second potential applied to the at least one bias electrode and converted into a charged electrolyte solution. In this regard, the charged electrolyte solution may be delivered through the at least one fluid delivery channel, exit the at least one bias electrode through the at least one nozzle, and arrive on a specific region of the workpiece, modifying the primary electric field and combating stray current corrosion of a finished part adjacent to the workpiece.

[0050] In an exemplary embodiment, the charged electrolyte solution flows out of the at least one nozzle 141 at a rate of 1 L / min to 50 L / min, e.g., 1 L / min to 25 L / min, e.g., 1 L / min to 10 L / min, e.g., 1 L / min to 5 L / min.

[0051] In some cases, in combination with charged electrolyte delivery, the electrolyte solution 190 can be continuously forced into the electrode gap 180 to rinse the workpiece 130 and tool electrode 120 at a flow rate of 0.5 L / sec to 20 L / sec, for example, 3.75 L / sec to 10 L / sec. Additionally, the electrolyte solution 190 can be continuously forced into the electrode gap 180 at a pressure of 350,000 Pa to 3,500,000 Pa.

[0052] In certain embodiments, combining biased anodic protection with charged electrolyte delivery has been shown to reduce the amount of "stray current corrosion" to the surface of the finished part adjacent to the workpiece being electrochemically machined. Evidence of the reduced amount of "stray current corrosion" to the adjacent finished part 150 is shown by the reduced amount of additional material removal and surface pitting experienced by the finished part 150 during electrochemical machining of the workpiece 130 when compared to electrochemically machining the workpiece 130 under the same conditions without biased anodic protection and charged electrolyte delivery.

[0053] In one embodiment, the delivery of a charged electrolyte solution substantially reduces the oxidation rate of the finished part 150 adjacent to the workpiece 130. Similarly, the reduction in the oxidation rate of the finished part 150 is indicated by a reduction in the amount of additional material removal and surface pitting that the finished part 150 experiences during electrochemical machining of the workpiece 130 when compared to electrochemically machining the workpiece 130 under the same conditions without biased anodic protection and charged electrolyte delivery.

[0054] Thus, as described herein, the present subject matter provides improved methods and systems for electrochemical machining. For example, the current state-of-the-art requires manual physical masking of finished parts adjacent to a workpiece to protect the surface from stray current corrosion. Conversely, the combination of biased anodic protection and charged electrolyte delivery, as described by the present disclosure, enables sequential processing of a workpiece with adjacent finished parts without the need for manual masking, by providing automated, closed-loop control of the electrochemical machine's primary electric field and an enhanced degree of protection from stray current corrosion. Specifically, as described herein, the combination of biased anodic protection and charged electrolyte delivery enables selective potential suppression at specific locations in the primary electric field, ensuring the quality of adjacent finished parts, even for parts with dense, complex features, such as bladed disks. Furthermore, the systems and methods described herein can be retrofitted to existing machines.

[0055] The technology described herein refers to computer-based systems and actions performed by, and information sent to, and received from, computer-based systems. Those skilled in the art will recognize that the inherent flexibility of computer-based systems allows for a wide variety of possible configurations, combinations, and divisions of tasks and functionality among components. For example, the processes described herein may be implemented using a single computing device or multiple computing devices operating in combination. Databases, memory, instructions, and applications may be implemented in a single system or distributed across multiple systems. Distributed components may operate sequentially or in parallel.

[0056] Further aspects of the present disclosure are provided by the subject matter of the following clauses.

[0057] A method for electrochemically machining a workpiece, the method comprising: applying a first potential to a tool electrode of an electrochemical machining system to generate a primary electric field, the electrochemical machining system including a workpiece opposite the tool electrode, at least one bias electrode, and at least one fluid delivery channel in the at least one bias electrode, the primary electric field being generated in an electrolyte solution between the tool electrode and the workpiece; applying at least one second potential to the at least one bias electrode; and delivering a charged electrolyte solution into the electrolyte solution through the at least one fluid delivery channel, the steps of applying the at least one second potential and delivering the charged electrolyte solution generating at least one secondary electric field adjacent to the primary electric field and potential suppressing at least one location of the primary electric field.

[0058] The method of any clause herein, wherein at least one spacer is disposed between the at least one bias electrode and the tool electrode.

[0059] The method of any clause herein, wherein the at least one spacer has a thickness of 100 micrometers to 2500 micrometers.

[0060] The method of any clause herein, wherein at least one bias electrode is electrically connected in series with the tool electrode and the workpiece.

[0061] The method of any clause herein, wherein the first electrical potential is a direct current potential of 5 volts to 50 volts.

[0062] The method of any clause herein, wherein the at least one second potential is a DC potential of 1 volt to 10 volts.

[0063] The method of any clause herein, wherein the first potential is a first pulsed potential and the at least one second potential is at least one second pulsed potential.

[0064] The method of any clause herein, wherein the first pulse potential has an average potential of 1 volt to 5 volts.

[0065] The method of any clause herein, wherein the at least one second pulse potential has an average potential of 1 volt to 5 volts.

[0066] The method of any clause herein, wherein the charged electrolyte solution is charged in the at least one fluid delivery channel by at least one second potential.

[0067] The method of any clause herein, wherein the charged electrolyte solution exits the at least one nozzle of the at least one electrode at a rate of 1 L / min to 50 L / min.

[0068] 10. The method of any clause herein, wherein the workpiece and the at least one bias electrode comprise a metallic material, the metallic material comprising a metallic alloy including a titanium-based alloy, a niobium-based alloy, a nickel-based alloy, a zirconium-based alloy, a palladium-based alloy, a platinum-based alloy, an aluminum-based alloy, a chromium-based alloy, a manganese-based alloy, a cobalt-based alloy, a molybdenum-based alloy, a hafnium-based alloy, a tungsten-based alloy, or a combination thereof.

[0069] The method of any clause herein, wherein delivering a charged electrolyte solution substantially reduces the oxidation rate of a finished component adjacent the workpiece.

[0070] The method of any clause herein, wherein the finished part is an airfoil.

[0071] The method of any clause herein, wherein the at least one second potential comprises two or more second potentials that are unique voltages relative to one another.

[0072] 1. An electrochemical machining system comprising: a tool electrode configured to generate a primary electric field between the tool electrode and a workpiece opposite the tool electrode; and at least one bias electrode positioned adjacent to the tool electrode, wherein the at least one bias electrode comprises at least one fluid delivery channel, and the at least one bias electrode is configured to generate at least one secondary electric field adjacent to the primary electric field.

[0073] The electrochemical machining system of any clause herein, wherein at least one bias electrode is electrically connected in series with the tool electrode and the workpiece.

[0074] The electrochemical machining system of any clause herein, further comprising a power source electrically connected to at least one bias electrode and the tool electrode.

[0075] The electrochemical machining system of any clause herein, further comprising an electrolyte source configured to deliver a charged electrolyte solution to the at least one fluid delivery channel.

[0076] The electrochemical machining system of any clause herein, wherein at least one spacer is disposed between the at least one bias electrode and the tool electrode.

[0077] This written description uses exemplary embodiments to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems, and performing any methods incorporated therein. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they contain structural elements that do not differ from the literal language of the claims, or if they contain structural elements that are equivalent to, but not substantially different from, the literal language of the claims.

[0078] Further aspects of the invention are provided by the subject matter of the following clauses.

[0079] [Item 1] A method for electrochemically machining a workpiece, the method comprising: applying a first potential to a tool electrode of an electrochemical machining system to generate a primary electric field, the electrochemical machining system including a workpiece opposite the tool electrode, at least one bias electrode, and at least one fluid delivery channel in the at least one bias electrode, the primary electric field being generated in an electrolyte solution between the tool electrode and the workpiece; applying at least one second potential to the at least one bias electrode; and delivering a charged electrolyte solution into the electrolyte solution through the at least one fluid delivery channel, the steps of applying the at least one second potential and delivering the charged electrolyte solution generating at least one secondary electric field adjacent to the primary electric field and potential suppressing at least one location of the primary electric field.

[0080] [Item 2] The method of any preceding item, wherein at least one spacer is disposed between the at least one bias electrode and the tool electrode.

[0081] [Item 3] The method of any preceding item, wherein at least one spacer has a thickness of 100 micrometers to 2500 micrometers.

[0082] [Item 4] The method of any preceding item, wherein at least one bias electrode is electrically connected in series with the tool electrode and the workpiece.

[0083] [Item 5] The method of any preceding item, wherein the first potential is a DC potential of 5 to 50 volts.

[0084] [Item 6] The method of any preceding item, wherein the at least one second potential is a DC potential between 1 volt and 10 volts.

[0085] [Item 7] The method of any preceding item, wherein the at least one second potential includes two or more second potentials that are unique voltages relative to one another.

[0086] [Item 8] The method of any preceding item, wherein the first potential is a first pulsed potential and the at least one second potential is at least one second pulsed potential.

[0087] [Item 9] The method of any preceding item, wherein the first pulse potential has an average potential of 1 volt to 5 volts.

[0088] [Item 10] The method of any preceding item, wherein at least one second pulse potential has an average potential of 1 volt to 5 volts.

[0089] [Item 11] The method of any preceding item, wherein the charged electrolyte solution is charged in at least one fluid delivery channel by at least one second potential.

[0090] [Item 12] The method of any preceding item, wherein the charged electrolyte solution exits at least one nozzle of at least one biased electrode at a rate of 1 L / min to 50 L / min.

[0091] [Item 13] The method of any preceding item, wherein the workpiece and at least one bias electrode comprise a metallic material, the metallic material comprising a metallic alloy, including a titanium-based alloy, a niobium-based alloy, a nickel-based alloy, a zirconium-based alloy, a palladium-based alloy, a platinum-based alloy, an aluminum-based alloy, a chromium-based alloy, a manganese-based alloy, a cobalt-based alloy, a molybdenum-based alloy, a hafnium-based alloy, a tungsten-based alloy, or a combination thereof.

[0092] [Item 14] The method of any preceding item, wherein delivering a charged electrolyte solution substantially reduces the oxidation rate of a finished component adjacent the workpiece.

[0093] [Item 15] The method of any preceding item, wherein the finished part is an airfoil.

[0094] [Item 16] An electrochemical machining system comprising: a tool electrode configured to generate a primary electric field between the tool electrode and a workpiece opposite the tool electrode; and at least one bias electrode positioned adjacent to the tool electrode, wherein the at least one bias electrode comprises at least one fluid delivery channel, and the at least one bias electrode is configured to generate at least one secondary electric field adjacent to the primary electric field.

[0095] [Item 17] The electrochemical machining system of any preceding item, further comprising at least one spacer disposed between the at least one bias electrode and the tool electrode.

[0096] [Item 18] The electrochemical machining system of any preceding item, wherein at least one bias electrode is electrically connected in series with the tool electrode and the workpiece.

[0097] [Item 19] The electrochemical machining system of any preceding item, further comprising a power source electrically connected to at least one bias electrode and the tool electrode.

[0098] [Item 20] The electrochemical machining system of any preceding item, further comprising an electrolyte source configured to deliver a charged electrolyte solution to the at least one fluid delivery channel. [Explanation of symbols]

[0099] 100 Electrochemical Machining System 112 Controller 113 Actuator 120 Tool Electrode 130 workpieces 140 bias electrode 141 nozzle 142 Charged Electrolyte Solution 143 Electrolyte Source 144 Fluid Delivery Channel 150 finished parts 160 spacer 170 Power supply 171 First Power Source 172 Second Power Source 180 Electrode Gap 190 Electrolyte solution 200 Primary electric field 210 Secondary Electric Field 400 Computing Systems 402 Computing Devices 404 processor 406 Memory Devices 408 Command 410 Data 412 Communication Interface

Claims

1. 1. A method for electrochemically machining a workpiece, comprising: applying a first potential to a tool electrode of an electrochemical machining system to generate a primary electric field, the electrochemical machining system including a workpiece opposite the tool electrode, at least one bias electrode, and at least one fluid delivery channel in the at least one bias electrode, the primary electric field being generated in an electrolyte solution between the tool electrode and the workpiece; applying at least one second potential to the at least one bias electrode; delivering a charged electrolyte solution through the at least one fluid delivery channel into the electrolyte solution, wherein the steps of applying at least one second electric potential and delivering the charged electrolyte solution generate at least one secondary electric field adjacent to the primary electric field to potential suppress at least one location of the primary electric field; A method comprising:

2. The method of claim 1 , wherein at least one spacer is disposed between the at least one bias electrode and the tool electrode.

3. The method of claim 2 , wherein the at least one spacer has a thickness of 100 micrometers to 2500 micrometers.

4. The method of claim 1 , wherein the at least one bias electrode is electrically connected in series with the tool electrode and the workpiece.

5. 2. The method of claim 1, wherein the first potential is a DC potential of 5 to 50 volts.

6. 10. The method of claim 1, wherein the at least one second potential is a DC potential between 1 volt and 10 volts.

7. The method of claim 1 , wherein the at least one second potential comprises two or more second potentials that are unique voltages relative to one another.

8. The method of claim 1 , wherein the first potential is a first pulsed potential and the at least one second potential is at least one second pulsed potential.

9. 9. The method of claim 8, wherein the first pulse potential has an average potential of 1 to 5 volts.

10. 9. The method of claim 8, wherein the at least one second pulse potential has an average potential of 1 to 5 volts.

11. The method of claim 1 , wherein the charged electrolyte solution is charged within the at least one fluid delivery channel by the at least one second electrical potential.

12. 10. The method of claim 1, wherein the charged electrolyte solution exits the at least one nozzle of the at least one biased electrode at a rate of 1 L / min to 50 L / min.

13. 10. The method of claim 1, wherein the workpiece and the at least one bias electrode comprise a metallic material, the metallic material comprising a metallic alloy including a titanium-based alloy, a niobium-based alloy, a nickel-based alloy, a zirconium-based alloy, a palladium-based alloy, a platinum-based alloy, an aluminum-based alloy, a chromium-based alloy, a manganese-based alloy, a cobalt-based alloy, a molybdenum-based alloy, a hafnium-based alloy, a tungsten-based alloy, or a combination thereof.

14. The method of claim 1 , wherein the step of delivering the charged electrolyte solution substantially reduces the oxidation rate of a finished component adjacent the workpiece.

15. The method of claim 14 wherein the finished part is an airfoil.

16. a tool electrode configured to generate a primary electric field between the tool electrode and a workpiece opposite the tool electrode; at least one bias electrode disposed adjacent to the tool electrode; the at least one biased electrode comprises at least one fluid delivery channel, and the at least one biased electrode is configured to generate at least one secondary electric field adjacent to the primary electric field.

17. The electrochemical machining system of claim 16 , further comprising at least one spacer disposed between the at least one bias electrode and the tool electrode.

18. The electrochemical machining system of claim 16 , wherein the at least one bias electrode is electrically connected in series with the tool electrode and the workpiece.

19. The electrochemical machining system of claim 16 further comprising a power supply electrically connected to the at least one bias electrode and the tool electrode.

20. 17. The electrochemical machining system of claim 16, further comprising an electrolyte source configured to deliver a charged electrolyte solution to the at least one fluid delivery channel.

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