Systems and methods for additive manufacturing magnetic solenoids

Systems and methods for forming a magnetically-enabled part via additive manufacturing. The method includes depositing a layer of additive manufacturing material on a build plate, melting or sintering the layer of additive manufacturing material, depositing additional layers of additive manufacturing material on previous layers of additive manufacturing material, the additive manufacturing material of at least some of the additional layers being magnetically permeable, and melting or sintering the additional layers of additive manufacturing material such that the magnetically-enabled part has a transition region including at least some of the magnetically permeable additive manufacturing material.

BACKGROUND

Magnetically-enabled parts typically include discrete non-magnetic structural features and discrete magnetic components. That is, the magnetic components embody basic, distinct volumes such as a disc or a wedge. The pronounced boundaries and homogenous composition of the distinct volumes restricts potential magnetic profiles of the magnetic components. Discrete structural features further inhibit or even interfere with the potential magnetic profiles of the magnetic components.

SUMMARY

Embodiments of the invention solve the above-mentioned problems and other problems and provide a distinct advancement in the art of manufacturing magnetically-enabled parts. More particularly, the invention provides systems and methods for additively manufacturing a magnetically-enabled part via magnetically permeable material. The magnetically permeable material may be concentrated in selected areas via transition regions to form a magnetically-enabled part having virtually any magnetic profile.

The invention allows for topology optimization in a design phase for magnetically-enabled parts. Specifically, non-structural material and non-magnetic flux paths can be removed from a part's geometry, resulting in a lower-mass design. The part may be built via additive manufacturing with the lower-mass design and still have comparable magnetic performance and strength. Similarly, magnetic performance may be improved or predictable and desirable assembly-level torque curves may be realized. Furthermore, magnetic topology optimization can be reversed to provide a given geometry (unique envelopes or unusual geometries), with design iterations being performed within those bounds to achieve desirable or predictable magnetic and mechanical performance.

An embodiment of the invention is an additive manufacturing system broadly comprising a frame, a build plate, a first additive manufacturing material reserve, a second additive manufacturing material reserve, a feeder, an additive manufacturing material deposition device, a directed energy source, a set of motors, a processor, and a heat-treatment device.

The frame provides structure for the build plate, feeder, directed energy source, and motors and includes a base, vertical members, cross members, and mounting points for mounting the above components thereto.

The build plate may be a stationary or movable flat tray or bed, a substrate, a mandrel, a wheel, scaffolding, or similar support. The build plate may be made of a dense stainless steel or other material similar to the first additive manufacturing material.

The additive manufacturing material reserves are substantially similar and each retains one of the additive manufacturing materials. Each additive manufacturing material reserve may be a hopper, tank, cartridge, container, spool, or other similar material holder.

The first additive manufacturing material may be a high strength steel, such as stainless steel, or other structural material. The first additive manufacturing material may be a powder, a filament, or any other suitable form.

The second additive manufacturing material may be a magnetically permeable material such as Hiperco®. The second additive manufacturing material may be a powder, an ink or other liquid, or any other suitable form.

The feeder may be a pump, an auger, or any other suitable feeder. Alternatively, the first additive manufacturing material and the second additive manufacturing material may be gravity fed to the additive manufacturing material deposition device.

The additive manufacturing material deposition device may include a nozzle, guide, sprayer, rake, or other similar component. The additive manufacturing material deposition device deposits the additive manufacturing material onto the build plate and previously constructed layers.

The directed energy source may be a laser, heater, or similar component for melting the first and second additive manufacturing materials and bonding (e.g., selective laser sintering (SLS) or selective laser melting (SLM)) the first and second additive manufacturing materials to a previously constructed layer. The directed energy source may be configured to melt the first and second additive manufacturing materials as they are deposited or melt the material of an entire layer after the layer has been deposited.

The motors position the additive manufacturing material deposition device over the build plate and previously constructed layers and move the additive manufacturing material deposition device as the first and second additive manufacturing materials are deposited onto at least one of the build plate and the previously constructed layers.

The processor directs the additive manufacturing material deposition device via the motors and activates the additive manufacturing material deposition device such that the additive manufacturing material deposition device deposits the additive manufacturing materials onto the build plate and previously constructed layers according to a computer aided design of the magnetically-enabled part. The processor may include at least one of a circuit board, memory, display, inputs, and other electronic components such as a transceiver or external connection for communicating with other external computers.

The heat-treatment device is configured to heat-treat the magnetically-enabled part on or off the build plate. The heat-treatment device may be an oven, a furnace, a heating element, or any other suitable heat-treatment device.

In use, the additive manufacturing system may deposit the first additive manufacturing material onto at least one of the build plate and previously constructed layers. The directed energy source may melt or sinter the first additive manufacturing material of the current layer. In this way, a base region formed of several layers of the first additive manufacturing material is built up on the build plate to a critical point in the geometry of the part.

Once the base region is completed, a mixture, combination, or alternating pattern of the first additive manufacturing material and the second additive manufacturing material may be deposited onto the previously constructed layers to form a transition region. The specific location and placement of the mixture, combination, or alternating pattern may be according to computer-aided design (CAD) data, or other technical model or drawing, as followed manually or by a user or as directed in an automated or semi-automated fashion. The directed energy source may then melt or sinter the mixture, combination, or alternating pattern of the current layer.

The transition region may include a predetermined number of layers at a known height and may be triggered by automated feed, calculated mass consumed, or other similar mechanisms. The transition region may occur multiple times and may be dependent on several factors such as build orientation, materials, and automatically changing parameters for each material. The transition region may also incorporate two, three, or more materials. In another embodiment, a series of transition regions may occur between subsequent materials (i.e., a first transition region between first and second materials followed by a second transition region between second and third materials).

Once the transition region is completed, only the second additive manufacturing material104may be deposited onto the previously constructed layers. The specific location and placement of the second additive manufacturing material104may be according to computer-aided design (CAD) data, or other technical model or drawing, as followed manually or by a user or as directed in an automated or semi-automated fashion. The directed energy source may then melt or sinter the second additive manufacturing material of the current layer.

The magnetically-enabled part may then be heat-treated via the heat-treatment device. To that end, the magnetically-enabled part may be heat-treated on the build plate or after being removed from the build plate.

The above-described invention provides several advantages. For example, magnetically permeable material may be used via additive manufacturing to create magnetically critical geometries otherwise impossible to machine via conventional manufacturing techniques. The magnetically-enabled part may be designed within unique design envelopes or with unusual geometries that may impact magnetic, electrical, or mechanical performance. The magnetically-enabled part may also include transition regions between materials to combine or merge different material properties within the magnetically-enabled part. Additive manufacturing also improves the turn-around time for development cycles, enabling faster design iterations and allowing additional time for application testing. Embodiments of the present invention may be used for Alternating Current (AC) and Direct Current (DC) applications and any magnetic and electro-mechanical devices.

The above-described system and method incorporate software optimization, geometric optimization, or topology optimization of magnetically-enabled designs previously unachievable with conventional manufacturing. The present invention also enables a reduction of mass for obtaining equivalent magnetic, electrical, or mechanical properties.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In this description, references to “one embodiment”, “an embodiment”, or “embodiments” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate references to “one embodiment”, “an embodiment”, or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, act, etc. described in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the current technology can include a variety of combinations or integrations of the embodiments described herein.

Broadly characterized, the present invention includes a system and method for additively manufacturing a magnetically-enabled part via magnetically permeable material. The magnetically permeable material may be concentrated in selected areas via transition regions such that the magnetically-enabled part exhibits bi-metallic or bi-material properties. This allows the magnetically-enabled part to have virtually any magnetic profile. That is, the systems and methods described herein enable the production of parts within unique design envelopes or with unusual geometries that impact magnetic and mechanical performance. The magnetically-enabled part may be a solenoid, a rotor, a stator, or any other suitable magnetically-enabled or electro-mechanical component.

The invention allows for topology optimization in a design phase for magnetically-enabled parts. Specifically, non-structural material and non-magnetic flux paths can be removed from a part's geometry, resulting in a lower-mass design. The part may be built via additive manufacturing with the lower-mass design and still have comparable magnetic performance and strength. Similarly, magnetic performance may be improved or predictable and desirable assembly-level torque curves may be realized. Furthermore, magnetic topology optimization can be reversed to provide a given geometry (unique envelopes or unusual geometries), with design iterations being performed within those bounds to achieve desirable or predictable magnetic and mechanical performance.

Turning toFIGS.1-3, an additive manufacturing system10constructed in accordance with an embodiment of the present invention is illustrated. The additive manufacturing system10broadly comprises a frame12, a build plate14, a first additive manufacturing material reserve16, a second additive manufacturing material reserve18, a feeder20, an additive manufacturing material deposition device22, a directed energy source24, a set of motors26, a processor28, and a heat-treatment device30.

The frame12provides structure for the build plate14, feeder20, directed energy source24, and motors26and may include a base, vertical members, cross members, and mounting points for mounting the above components thereto. Alternatively, the frame12may be a walled housing or similar structure.

The build plate14may be a stationary or movable flat tray or bed, a substrate, a mandrel, a wheel, scaffolding, or similar support. The build plate14may be made of a dense stainless steel or other material similar to the first additive manufacturing material102. The build plate14may be integral with the additive manufacturing system10or may be removable and integral with an magnetically-enabled part100being formed (as discussed in more detail below).

The first additive manufacturing material reserve16retains the first additive manufacturing material102and may be a hopper, tank, cartridge, container, spool, or other similar material holder. The first additive manufacturing material reserve16may be integral with the additive manufacturing system10or may be at least one of disposable and reusable.

The first additive manufacturing material102may be a high strength steel, such as stainless steel, or other structural material. The first additive manufacturing material104may be a powder, a filament, or any other suitable form.

The second additive manufacturing material reserve18retains the second additive manufacturing material104and may be a hopper, tank, cartridge, container, spool, or other similar material holder. The second additive manufacturing material reserve18may be integral with the additive manufacturing system10or may be at least one of disposable and reusable.

The second additive manufacturing material104may be a magnetically permeable material such as Hiperco®. The second additive manufacturing material104may be a powder, an ink or other liquid, or any other suitable form.

The feeder20may be a pump, an auger, or any other suitable feeder. Alternatively, the first additive manufacturing material102and the second additive manufacturing material104may be gravity fed to the additive manufacturing material deposition device22. The feeder20connects to both additive manufacturing material reserves16,18and may mix the first and second additive manufacturing materials102,104together in any mixture percentage by weight, volume, or any other suitable metric.

The additive manufacturing material deposition device22may include a nozzle, guide, sprayer, rake, or other similar component for depositing the additive manufacturing material104onto the build plate14and previously constructed layers.

The directed energy source24may be a laser, heater, or similar component for melting the first additive manufacturing material102and the second additive manufacturing material104and bonding (e.g., selective laser sintering (SLS) or selective laser melting (SLM)) the first additive manufacturing material102and the second additive manufacturing material104to a previously constructed layer. The directed energy source24may be configured to melt the first additive manufacturing material102and the second additive manufacturing material104as it is being deposited or melt the material of an entire layer after the layer has been deposited.

The motors26position the additive manufacturing material deposition device22over the build plate14and previously constructed layers and move the additive manufacturing material deposition device22as at least one of the first additive manufacturing material102and the second additive manufacturing material104are deposited onto at least one of the build plate14and the previously constructed layers. The motors26may be oriented orthogonally to each other so that a first one of the motors26is configured to move the additive manufacturing material deposition device22in a lateral “x” direction, a second one of the motors26is configured to move the additive manufacturing material deposition device22in a longitudinal “y” direction, and a third one of the motors26is configured to move the additive manufacturing material deposition device22in an altitudinal “z” direction. Alternatively, the motors26may move the build plate14(and hence the magnetically-enabled part100) while the additive manufacturing material deposition device22remains stationary.

The processor28directs the additive manufacturing material deposition device22via the motors26and activates the additive manufacturing material deposition device22such that the additive manufacturing material deposition device22deposits the additive manufacturing material104onto the build plate14and previously constructed layers according to a computer aided design of the magnetically-enabled part100. The processor28may include at least one of a circuit board, memory, display, inputs, and other electronic components such as a transceiver or external connection for communicating with other external computers.

The processor28may implement aspects of the present invention with one or more computer programs stored in or on computer-readable medium residing on or accessible by the processor. Each computer program preferably comprises an ordered listing of executable instructions for implementing logical functions in the processor28. Each computer program can be embodied in any non-transitory computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device, and execute the instructions. In the context of this application, a “computer-readable medium” can be any non-transitory means that can store the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can be, for example, but not limited to, an electronic, magnetic, optical, electro-magnetic, infrared, or semi-conductor system, apparatus, or device. More specific, although not inclusive, examples of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a random access memory (RAM), a read-only memory (ROM), an erasable, programmable, read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disk read-only memory (CDROM).

The heat-treatment device30is configured to heat-treat the magnetically-enabled part on or off the build plate14. The heat-treatment device30may be an oven, a furnace, a heating element, or any other suitable heat-treatment device.

Turning toFIG.4, and with reference toFIGS.1-3, use of the additive manufacturing system10will now be described in more detail. First, the first additive manufacturing material102may be positioned in the first additive manufacturing material reserve16and the second additive manufacturing material104may be positioned in the second additive manufacturing material reserve18, as shown in block200.

The first additive manufacturing material102may then be fed to the additive manufacturing material deposition device22via the feeder20, as shown in block202. The additive manufacturing material104may be metered in discrete amounts or continuously, depending on movement and position of the material mixture deposition device28.

The additive manufacturing material deposition device22may then deposit the first additive manufacturing material102onto at least one of the build plate14and previously constructed layers, as shown in block204. The specific location and placement of the additive manufacturing material104may be according to computer-aided design (CAD) data, or other technical model or drawing, as followed manually or by a user or as directed in an automated or semi-automated fashion via control signals provided from the processor28to the motors26.

The directed energy source24may then melt or sinter the first additive manufacturing material102of the current layer, as shown in block206. This may include tracing the directed energy source24over or through the current layer according to CAD data, models, drawings, or other technical resources. The first additive manufacturing material102may fuse together. Alternatively or additionally, the first additive manufacturing material102may fuse to additive manufacturing material of a previous layer.

Steps202-206may be repeated multiple times as needed. For example, once one layer of the magnetically-enabled part100has been fused, another layer of the first additive manufacturing material102may be deposited. This may be accomplished through first lowering the build plate14relative to the material mixture deposition device22and directed energy source24. In this way, a base region formed of several layers of the first additive manufacturing material102is built up on the build plate14to a critical point in the geometry of the part100. The base region may include geometries needing high strength (e.g., threaded holes, standoffs, bosses, locating holes, and the like). To that end, the base region may include at least a portion of the build plate14or other pre-manufactured components or features.

Once the base region is completed, a mixture, combination, or alternating pattern of the first additive manufacturing material102and the second additive manufacturing material104may be fed to the additive manufacturing material deposition device22via the feeder20, as shown in block208. The mixture, combination, or pattern may be metered in discrete amounts or continuously, depending on movement and position of the material mixture deposition device28.

The additive manufacturing material deposition device22may then deposit the mixture, combination, or alternating pattern onto the previously constructed layers to form a transition region, as shown in block210. The specific location and placement of the mixture, combination, or alternating pattern may be according to computer-aided design (CAD) data, or other technical model or drawing, as followed manually or by a user or as directed in an automated or semi-automated fashion via control signals provided from the processor28to the motors26.

The directed energy source24may then melt or sinter the mixture, combination, or alternating pattern of the current layer, as shown in block212. This may include tracing the directed energy source24over or through the current layer according to CAD data, models, drawings, or other technical resources. The mixture, combination, or alternative pattern may fuse together. Alternatively or additionally, the mixture, combination, or alternative pattern may fuse to additive manufacturing material of a previous layer.

Steps208-212may be repeated multiple times as needed. The transition region may include a predetermined number of layers at a known height and may be triggered by automated feed, calculated mass consumed, or other similar mechanisms. The transition region may include a predetermined transition gradient from the first additive manufacturing material102to the second additive manufacturing material104. The transition gradient may be linear, sinusoidal, exponential, stepped, or any other suitable gradient.

The transition region may occur multiple times and may be dependent on several factors such as build orientation, materials, and automatically changing parameters for each material. The transition region may also incorporate two, three, or more materials. In another embodiment, a series of transition regions may occur between subsequent materials (i.e., a first transition region between first and second materials followed by a second transition region between second and third materials).

Once the transition region is completed, only the second additive manufacturing material104may be fed to the additive manufacturing material deposition device22via the feeder20, as shown in block214. The second additive manufacturing material104may be metered in discrete amounts or continuously, depending on movement and position of the material mixture deposition device28.

The additive manufacturing material deposition device22may then deposit the second additive manufacturing material104onto the previously constructed layers, as shown in block216. The specific location and placement of the second additive manufacturing material104may be according to computer-aided design (CAD) data, or other technical model or drawing, as followed manually or by a user or as directed in an automated or semi-automated fashion via control signals provided from the processor28to the motors26.

The directed energy source24may then melt or sinter the second additive manufacturing material104of the current layer, as shown in block218. This may include tracing the directed energy source24over or through the current layer according to CAD data, models, drawings, or other technical resources. The second additive manufacturing material104may fuse together. Alternatively or additionally, the second additive manufacturing material104may fuse to additive manufacturing material of a previous layer. Steps214-218may be repeated multiple times as needed.

In some embodiments, an additional layer of the first additive manufacturing material102or an additional transition region may then be added. That is, a region made of only one additive manufacturing material may be flanked on both sides by transition regions or any other combination of materials such as homogenous regions of the same or different materials. Similarly, a transition region may be flanked by homogeneous regions of the same or different materials or transition regions including other materials. In this way, material gradients may have virtually any suitable pattern. This allows for the electro-mechanical part100to have virtually any distribution of magnetic, electrical, or mechanical properties for specific applications.

The magnetically-enabled part100may then be heat-treated via the heat-treatment device30, as shown in block220. To that end, the magnetically-enabled part100may be heat-treated on the build plate14or after being removed from the build plate14.

In one embodiment, the magnetically-enabled part100may include at least a portion of the build plate14itself. The build plate14could serve as the base region or a portion thereof and may be machined to include some of the desired base geometries of the magnetically-enabled part100. For example, the magnetically-enabled part100may include a stainless steel bar formed by the build plate14, a transition region including less dense stainless steel and some magnetically permeable material, and a terminal region including only magnetically permeable material. This could also be reversed or reordered as desired.

The above-described invention provides several advantages. For example, magnetically permeable material may be used via additive manufacturing to create magnetically critical geometries otherwise impossible to machine via conventional manufacturing techniques. The magnetically-enabled part100may be designed within unique design envelopes or with unusual geometries that may impact magnetic, electrical, or mechanical performance. The magnetically-enabled part100may also include transition regions between materials to combine or merge different material properties within the magnetically-enabled part100. Additive manufacturing also improves the turn-around time for development cycles, enabling faster design iterations and allowing additional time for application testing. Embodiments of the present invention may be used for Alternating Current (AC) and Direct Current (DC) applications and any magnetic and electro-mechanical devices.

The above-described system and method incorporate software optimization, geometric optimization, or topology optimization of magnetically-enabled designs previously unachievable with conventional manufacturing, which may be used to improve a magnetic profile, a mechanical characteristic, or other characteristics of the magnetically-enabled part. The present invention also enables a reduction of mass for obtaining equivalent magnetic, electrical, or mechanical properties.

The present invention eliminates brittleness issues from which non-heat treated magnetically permeable materials suffer. Components formed of such materials do not have enough strength for mounting within stronglinks in extreme environments.

The above-described steps may be performed in any order, including simultaneously. In addition, some of the steps may be at least one of repeated, duplicated, and omitted without departing from the scope of the present invention.