ADDITIVE MANUFACTURING SYSTEM WITH A MOVABLE OUTLET

Abstract

An additive manufacturing system and process comprises a melting mechanism, an outlet, and a controller. The system and process are carried out in a chamber containing a layer of particles. The melting mechanism emits a jet to melt the particles in the particle layer. The melting mechanism is configured to move the jet along a melt path extending from one end of the chamber to the other in a first direction. The outlet is movable in the first direction and configured to expel air in a second direction opposite to the first. The controller is configured to move the outlet in the first direction and keep it upstream of the jet.

Description

INTRODUCTION

[0001] The information in this section is intended to provide a general context for the disclosure. Work by the presently named inventors, to the extent described in this section, as well as aspects of the description that may not be prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[0002] This disclosure generally relates to a system and method for additive manufacturing. Fig. Figure 1 shows an illustration of an additive manufacturing process commonly referred to as powder bed fusion. The additive manufacturing process is performed in a chamber 100 containing a layer of particles 102 that are to be fused together to form a desired component. The particles are fused together by a beam "B," e.g., a laser or electron beam. The process is an iterative process in which the particles in layer 102 are fused together, and then another layer 102 of particles is added and fused together until the component is printed.

[0003] The energy of beam "B" creates a particle cloud "CP" that spreads upward from the particle layer 102. As a result, the particle cloud "CP" absorbs energy from the beam, which can lead to an undesirable fusion process. For example, the energy of the beam can be absorbed by the particles in the cloud, resulting in reduced particle fusion performance. Furthermore, the energy of the beam can fuse the particles in the cloud, creating a fused particle "FP" that falls into an undesirable / unintended location and causes a defect in the printed component.

[0004] According to Fig. 2, current systems are equipped with a blower 104 and an outlet 106 attached to one end of the chamber 100. The outlet 106 directs gas, e.g., an inert gas, from one end of the chamber 100 into an inlet 108. The blower 104 is configured to blow the gas through the outlet 106 at a flow velocity strong enough to force particles from the cloud into the inlet 108 without disturbing the particles in the particle layer 102. Thus, Fig. 2, how the gas is blown over the particle layer 102 without blowing away particles with the layer 102, and transports particles in the cloud into an inlet 108.

[0005] Fig. Figure 3 shows an illustrative view of a chamber 100 for additive manufacturing. Within the chamber 100 is a jet generator 110 configured to generate a jet for fusing the particles. The chamber 100 includes an outlet 106 attached to one end of the chamber 100 and positioned above the particle layer 102 so as not to blow directly onto the particle layer 102. Thus, the outlet 106 is positioned to impact only the cloud of particles generated by the particle-fusing jet "B" and not the particle layer 102 itself.

[0006] Again according to Fig. 3 and now on Fig. 4, the strength of the gas blown through outlet 106 decreases with distance, as indicated by the decrease in the size of the arrows. As previously mentioned, outlet 106 is attached to a first end of chamber 100, and an inlet 108 may be attached to a second end of chamber 100. The jet is emitted by jet generator 110, which directs the jet along a melting path that travels the length of chamber 100 from the first end to the second end. Because outlet 106 is attached to the first end of chamber 100, blower 104 can very effectively carry the particles away in a cloud when melting occurs near outlet 106. However, the effectiveness of the blower decreases the farther away from outlet 106 the melting occurs. Conventional chambers 100 are designed to be covered with a layer of powder over a length of approximately 400 mm. Fig. Figure 4 shows that the gas flow rate is relatively constant when blown over a distance of 400 mm, and decreases rapidly beyond 400 mm. Therefore, increasing the length of the chamber 100 reduces the effectiveness of the blower, and increasing the blower speed to increase the length of the chamber 100 would disturb the particles in the particle layer, resulting in an uneven layer thickness after melting.

[0007] While conventional systems adequately blow away the particles in a cloud generated by the melting process, the length of the particle layer within the chamber is limited to approximately 400 mm, and thus the length of the component to less than 400 mm. Therefore, it is desirable to increase the length of the chamber and thus increase the size of the component that can be printed. In addition, it is desirable to remove the particles in the cloud generated during melting to provide the laser with an unobstructed path to the melt. Furthermore, it is desirable to eliminate defects in the printing process by removing particles melted in the cloud from the chamber. SUMMARY

[0008] In one configuration, an additive manufacturing system includes a melting mechanism, an outlet, and a controller. The system operates in a chamber containing a layer of particles. The melting mechanism emits a jet to melt the particles in the layer of particles. The melting mechanism is configured to move the jet along a melting path extending from one end of the chamber to another end of the chamber in a first direction. The outlet is movable in the first direction and configured to blow air in a second direction opposite the first direction. The controller is configured to move the outlet in the first direction and keep the outlet upstream of the jet.

[0009] The system may include one or more of the following optional features. The beam may, for example, be a laser beam or an electron beam.

[0010] In one configuration, the outlet may extend across a width of the chamber.

[0011] In one configuration, the system may further include a rail extending the length of the chamber, and the outlet is movably disposed along the rail.

[0012] In one configuration, the system may include an inlet configured to draw air from inside the chamber to an environment outside the chamber. In such a configuration, the inlet may be attached to one end of the chamber and spaced from the outlet. The inlet may be sized to span the width of the chamber. Alternatively, the inlet may be movable relative to the outlet to accommodate the melt trajectory of the jet.

[0013] In one configuration, the controller is configured to move the outlet and inlet between a start position and an end position. In such a configuration, the controller can be configured so that the outlet remains upstream of the jet and the inlet remains downstream of the jet while the jet moves along the melt path. The controller can further be configured so that the jet returns to the start position when it has completed the melt path.

[0014] In another configuration, an additive manufacturing system includes a chamber containing a layer of particles, the system including a melting mechanism that emits a jet to melt particles in the layer of particles. The melting mechanism may be configured to move the jet along a melting path extending from one end of the chamber to another end of the chamber in a first direction. The system includes an inlet movable in the first direction and configured to draw in air in the first direction, and a controller configured to move the inlet in the first direction and maintain the inlet upstream of the jet. In such a configuration, the system may further include an outlet configured to blow air in the first direction, the outlet spaced from the inlet.

[0015] In another configuration, a method for performing additive manufacturing includes fusing particles in a layer of particles with a jet. The jet moves along a melt path from one end of a chamber to another end of the chamber in a first direction. The method includes providing an outlet for blowing air in a second direction opposite the first direction and moving the outlet along the first direction. The method includes maintaining the outlet upstream of the melt path to blow air downstream of the melt path.

[0016] In one configuration, melting particles in a particle layer with a beam includes a laser beam or an electron beam.

[0017] In one configuration, the outlet may extend across a width of the chamber.

[0018] In one configuration, moving the outlet along the first direction comprises moving the outlet along a track extending the length of the chamber. In such a configuration, the method may include providing an inlet configured to draw air from inside the chamber to an environment outside the chamber. In one aspect, the inlet may be located a predetermined distance from the outlet to facilitate the melt path. In one aspect, the inlet may extend the width of the chamber.

[0019] In one configuration, the method includes a controller moving the inlet relative to the outlet to adjust the melt path of the jet. In such a configuration, the method may include the controller moving the outlet and the inlet between a start position and an end position. In another aspect of such a configuration, the method may include the controller maintaining the outlet upstream of the jet and the inlet downstream of the jet while the jet moves along the melt path and returning the jet to the start position when the jet has completed the melt path. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Fig. 1 is a perspective view of a melting process of particles by means of a jet; Fig. Figure 2 is a side view of a conventional single-beam additive manufacturing system; Fig. 3 is a perspective view of a conventional additive manufacturing chamber showing an outlet attached to one end of the chamber and the rate of decrease of a gas from one end of the chamber to the other end; Fig. Figure 4 is a schematic diagram showing how the strength of the gas flow decreases with distance; Fig. 5 is a perspective view of an additive manufacturing system showing an outlet movable in a first direction and blowing air in a second direction opposite the first direction; Fig. 6 is a plan view of the Fig. 5, in which rails are configured to direct gas into an outlet; Fig. 7 is a side view showing the operation of the system of Fig. 5 shows; Fig. 8 is a perspective view of an additive manufacturing system showing an inlet spaced from an outlet and movable in a first direction; Fig. 9 is a plan view of the Fig. The system shown in Figure 8, which shows rails configured to direct gas into the outlet; Fig. 10 is a side view showing the operation of the system of Fig. 8 shows; Fig. 11 is a plan view of an additive manufacturing system showing an inlet movable in a first direction and drawing in air in a first direction; Fig. 12 is a plan view of an additive manufacturing system showing an inlet and an outlet, both movable in a first direction; and Fig. Figure 13 is a flowchart showing an additive manufacturing process.

[0021] Corresponding reference numbers indicate corresponding parts in the drawings. DETAILED DESCRIPTION

[0022] Example configurations will now be described in more detail with reference to the accompanying drawings. Example configurations are provided so that this disclosure will be thorough and will convey the full scope of the disclosure to those skilled in the art. Specific details are set forth, such as examples of specific components, devices, and methods, in order to provide a thorough understanding of configurations of the present disclosure. Those skilled in the art will appreciate that specific details need not be used, that example configurations may be implemented in many different forms, and that the specific details and example configurations should not be construed to limit the scope of the disclosure.

[0023] The terminology used herein is for the purpose of describing specific example configurations only and is not intended to be limiting. As used herein, the singular articles "a," "an," and "the" can also include the plural forms unless the context clearly indicates otherwise. The terms "comprises," "comprising," "containing," and "having" are inclusive and therefore specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein should not be construed as necessarily being performed in the order discussed or illustrated unless they are expressly identified as being in order of performance.Additional or alternative steps may be applied.

[0024] When an element or layer is described as being "on," "engaging," "connected," "attached to," or "coupled" to another element or layer, it may be directly on, engaging, connected, attached, or coupled to the other element or layer, or there may be intervening elements or layers. Conversely, when an element is described as being "directly on," "directly engaging," "directly connected to," "directly attached to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. Other words used to describe the relationship between elements should be interpreted similarly (e.g., "between" versus "directly between," "adjacent" versus "directly next to," etc.).As used herein, the term “and / or” includes all combinations of one or more of the related listed items.

[0025] The terms "first," "second," "third," etc., may be used herein to describe various elements, components, regions, layers, and / or sections. These elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer, or section from another region, layer, or section, respectively. Terms such as "first," "second," and other numerical terms do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer, or section discussed below could be referred to as a second element, component, region, layer, or section without departing from the teachings of the example configurations.

[0026] In this application, including the definitions below, the term "module" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include: an application-specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field-programmable gate array (FPGA); a processor (shared, dedicated, or group) executing code; memory (shared, dedicated, or group) storing code executed by a processor; other suitable hardware components providing the described functionality; or a combination of some or all of the above, e.g., in a system-on-chip.

[0027] The term "code" as used above can include software, firmware and / or microcode and can refer to programs, routines, functions, classes, and / or objects. The term "shared processor" includes a single processor that executes some or all of the code from multiple modules. The term "group processor" includes a processor that, in combination with other processors, executes some or all of the code from one or more modules. The term "shared memory" includes a single memory that stores some or all of the code from multiple modules. The term "group memory" includes memory that, in combination with other memory, stores some or all of the code from one or more modules. The term "memory" can be a subset of the term "computer-readable medium".The term "computer-readable medium" does not encompass transitory electrical and electromagnetic signals propagating through a medium and can therefore be considered tangible and non-transitory storage. Non-limiting examples of non-transitory storage include tangible, computer-readable medium, including non-volatile memory, magnetic storage, and optical storage.

[0028] The devices and methods described in this application may be implemented partially or entirely by one or more computer programs executed by one or more processors. The computer programs include processor-executable instructions stored on at least one non-transitory, tangible, computer-readable medium. The computer programs may also include and / or access stored data.

[0029] A software application (i.e., a software resource) may refer to computer software that causes a computing device to perform a task. In some examples, a software application may be referred to as an "application," "app," or "program." Example applications include, but are not limited to, system diagnostic applications, system management applications, system maintenance applications, word processing applications, spreadsheet applications, messaging applications, media streaming applications, social networking applications, and gaming applications.

[0030] Non-transitory memory can be physical devices used to temporarily or permanently store programs (e.g., instruction sequences) or data (e.g., program state information) for use by a computing device. Non-transitory memory can be volatile and / or non-volatile addressable semiconductor memory. Examples of non-volatile memory include flash memory and read-only memory (ROM) / programmable read-only memory (PROM) / erasable programmable read-only memory (EPROM) / electronically erasable programmable read-only memory (EEPROM) (e.g., typically used for firmware such as boot programs). Examples of volatile memory include random-access memory (RAM), dynamic random-access memory (DRAM), static random-access memory (SRAM), phase-change memory (PCM), and floppy disks or tapes.

[0031] These computer programs (also referred to as programs, software, software applications, or code) contain machine instructions for a programmable processor and may be implemented in a procedural and / or object-oriented high-level language and / or assembly / machine language. As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, non-transitory computer-readable medium, apparatus, and / or device (e.g., magnetic disks, optical disks, memory, programmable logic devices (PLDs)) designed to deliver machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal.The term “machine-readable signal” refers to any signal used to convey machine instructions and / or data to a programmable processor.

[0032] Various implementations of the systems and techniques described herein may be realized in digital electronic and / or optical circuits, integrated circuits, purpose-built ASICs (application-specific integrated circuits), computer hardware, firmware, software, and / or combinations thereof. These various implementations may include implementation in one or more computer programs executable and / or interpretable on a programmable system comprising at least one programmable processor, which may be used for special or general purposes and is coupled to receive data and instructions from and transmit data and instructions to a storage system, and at least one input device and at least one output device.

[0033] The processes and logic flows described in this specification may be performed by one or more programmable processors, also known as data processing hardware, which run one or more computer programs to perform functions by responding to input data and generating output. The processes and logic flows may also be performed by special-purpose logic circuits, such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). Processors suitable for executing a computer program include, for example, both general-purpose and special-purpose microprocessors, as well as one or more processors of any type of digital computer. Generally, a processor receives instructions and data from read-only memory or random-access memory, or both.The essential elements of a computer are a processor for executing instructions, and one or more storage devices for storing instructions and data. Generally, a computer will also include, or be operatively connected to, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical, or optical disks, or to receive or transfer data to or from them. However, a computer is not required to have such devices. Computer-readable media suitable for storing computer program instructions and data includes all forms of non-volatile memory, media, and storage devices, including, for example, semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable media; magneto-optical disks; and CD-ROM and DVD-ROM disks.The processor and memory can be supplemented by or integrated into special logic circuits.

[0034] To enable interaction with a user, one or more aspects of the disclosure may be implemented on a computer having a display device, e.g., a CRT (cathode ray tube), LCD (liquid crystal display) monitor, or a touchscreen for displaying information to the user, and optionally a keyboard and pointing device, e.g., a mouse or trackball, with which the user can provide input to the computer. Other types of devices may also be used to interact with the user; for example, the feedback to the user may be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user may be received in any form, including auditory, voice, or tactile input.In addition, a computer can interact with a user by sending and receiving documents to and from a device used by the user; for example, by sending web pages to a web browser on a user's client device in response to requests received from the web browser.

[0035] A system and method for additive manufacturing includes a melting mechanism, an outlet, and a controller. The controller moves the outlet in the first direction and keeps the outlet upstream of the jet, and the outlet is configured to blow air in a second direction opposite the first direction, thereby blowing particles in a cloud out of the path of the melting mechanism's jet. Because the outlet is movable along the chamber, the size of the chamber is unlimited, and thus the size of the component to be printed by the additive manufacturing process. Because the outlet moves with the melting trajectory of the jet, particles from the cloud are blown into the inlet and removed from the chamber, avoiding imperfections caused by particles of the cloud that are melted and fall onto the printed layer.

[0036] Additionally, the system and method may include an inlet spaced from the outlet and movable along the first direction. The inlet provides a passage for particles from the cloud to be removed from the chamber.

[0037] In one aspect, the outlet and inlet are mounted on a rail system and are moved along the rail system by a controller. The rail system may be configured to provide a conduit for gas. In another aspect, the rail system may be configured to distribute a layer of particles for melting.

[0038] With reference to Fig. 5 - 7, an additive manufacturing system 10 is provided that is configured to print a component (not shown). The system 10 is arranged in a chamber 12. The chamber 12 is enclosed by a bottom wall 14a, four side walls 16, and a top wall 14b (see Fig. 7). To facilitate the description of the system 10, one of the side walls and the top wall is in Fig. 5. One of the four side walls is a first wall 16a, and another of the four side walls is a second wall 16b spaced from and facing the first wall 16a. The distance between the first wall 16a and the second wall 16b defines a length "L" of the chamber 12, and the width of the first wall 16a and the second wall 16b defines a width "W" of the chamber 12.

[0039] A layer of particles 18 to be fused together is placed on the bottom wall 14a of the chamber 12. Once the particles are fused together, another layer of particles 18 is added, and this process is repeated until the component is printed. In other words, the component is printed layer by layer. The added layer of particles 18 need not cover the entire bottom surface, but can be discretely applied to the previous layer, depending on the design of the printed component. Any particles suitable for a fusion process that are currently known or later developed can be modified for use in the system 10, including metallic particles and polymer particles, such as titanium, aluminum alloys, stainless steel, nickel- and copper-based alloys, nylon, nylon composites, polypropylene, thermoplastics, and the like.

[0040] The system 10 includes a melting mechanism 20 (shown in Fig. 7). The fusing mechanism 20 is configured to generate an energy beam (as indicated by the arrow) of sufficient power to fuse the particles together. The fusing mechanism 20 may include one or more beam generators 20a, 20b. In one aspect, the beam generator 20a is a laser beam generator for generating a laser beam, and the beam generator 20b is an electron beam generator for generating an electron beam. It should be understood that any currently known or later developed fusing mechanism 20 for fusing particles together may be modified for use herein.

[0041] The system 10 may include a dispensing mechanism 22 configured to dispense particles to form the particle layer 18, as shown in Fig. 7. Any dispensing mechanism 22 currently known and used in the art may be modified for use herein, e.g., a hopper, a rake, a powder pumping device, and the like. The dispensing mechanism 22 is disposed above the bottom wall 14a of the chamber 12 and is configured to selectively dispense the particles. For example, the dispensing mechanism 22 may be movable within the chamber 12 or may be stationary and include a movable or rotatable nozzle for distributing particles to a predetermined area of ​​the chamber 12.

[0042] The melting mechanism 20 emits a beam "B" that has sufficient energy to melt the particles in the particle layer 18. As previously mentioned, the melting process creates a cloud of particles that can obstruct the beam, and / or the beam can melt the particles in the cloud, and the melted particles can land on the printed layer and cause undesirable defects. The melting mechanism 20 is configured to move the beam "B" in a melting path that extends from one end of the chamber 12 to another end of the chamber 12 in a first direction "1D." The first direction "1D" extends the length of the chamber 12 from the first wall 16a to the second wall 16b.

[0043] It should be noted that the melt path is not necessarily limited to one direction, but may also include a pattern applied to a portion of the particle layer 18 to be melted together to form the corresponding layer of the printed component. For example, the melting mechanism 20 may direct the beam along the entire width of the chamber 12 and along a predetermined length of the chamber 12 to define a melting region before the beam is translated in the first direction "1D." Therefore, as the beam is moved along the width, it may be aligned to cover a predetermined length of the particle layer 18. When using multiple laser beam generators 20a and / or electron beam generators 20b, multiple beams may be employed, with each beam moving in a pattern that, taken together, forms a printed layer of the component.The term melt path is therefore not limited to a movement of the beam in a single direction, but refers to the movement of the beam to complete a printed component layer by layer.

[0044] The system 10 includes an outlet 24 that is movable in the first direction "1D" and configured to direct gas in a second direction "2D" opposite to the first direction "1D". In one aspect, the gas may be an inert gas such as argon and nitrogen. A blower 26 is fluidly connected to the outlet 24 and configured to blow the gas at a predetermined flow rate sufficient to entrain the particles contained in the cloud formed by the melting process without disturbing the particles in the layer. For example, the blower 26 may be configured to blow the gas at a flow rate of 150-350 m 3 / h in an additive process for melting aluminum particles with an average particle size of 15-63 µm. Such a flow rate is sufficient to carry / blow the aluminum particles out of the beam path in a cloud without disturbing or otherwise moving the particles in the particle layer 18 to be melted. The flow rate of the gas can vary depending on the type, size, and mass of the particles to be melted, and the flow rate can be increased or decreased compared to the description without deviating from the scope of the associated claims. Fig. Figure 5 shows a configuration in which the fan 26 is arranged within the outlet 24, and Fig. Figure 6 shows a configuration in which the fan 26 is located outside the chamber 12 and fluidly connected to the outlet 24. For illustrative purposes, the system 10 is shown with a pair of fans 26, each connected to opposite ends of the outlet 24. However, the system 10 can also be configured to use a single fan 26.

[0045] In Fig. 5, the outlet 24 is shown as an elongated member having a generally cuboid shape with a slot 28 extending substantially the length of the outlet 24 through which gas is blown. The length of the outlet 24 is less than the width of the chamber 12. The cuboid shape of the outlet 24 is for illustrative purposes only, and it should be understood that the outlet 24 may be shaped differently. For example, the outlet 24 may be cylindrical. The outlet 24 may further include pivotable ribs (none shown) that direct the gas through the slot 28. In one aspect, the outlet 24 extends the width of the chamber 12, and in such an aspect, the slot 28 may also extend the width of the chamber, as in Fig. 6 shown.

[0046] In another aspect of the system 10, the outlet 24 can be attached to a track system 30. The track system 30 is configured to guide the outlet 24 in the first direction "1D" along the length of the chamber 12. In one aspect, the track system 30 includes a pair of tracks 30a, 30b, the two tracks 30a, 30b being spaced apart from each other and configured to receive a length of the outlet 24. A movement mechanism 32 moves the outlet 24 along the track system 30. The movement mechanism 32 can be located on the outlet 24 or on the track system 30, or on both the outlet 24 and the track system 30. In one aspect, the movement mechanism 32 is a drive piston that can be extended and retracted along the length of the chamber 12.The drive piston has a first end attached to the first wall 16a and a second end attached to a rear side 24a of the outlet 24, the rear side 24a of the outlet 24 facing away from a front side 24b of the outlet where the slot 28 is located. Any currently known, used, or later developed movement mechanism 32 may be adapted and modified for use herein. The movement mechanism 32 may, for example, be a rotary motor (not shown) disposed at the outlet 24 and coupled to a gear (not shown). The rails 30a, 30b are a track with teeth (not shown) into which the gears can engage to advance the outlet 24 back and forth along the track.

[0047] The system 10 includes a controller 34 connected to the outlet 24 and the fusing mechanism 20. The controller 34 is configured to move the outlet 24 in the first direction "1D" and to maintain the outlet 24 upstream of the jet. The controller 34 may be a programmable logic controller configured to provide the outlet 24 and the fusing mechanism 20 with a set of operating instructions for printing the component. It should be noted that the controller 34 may include memory hardware 34a containing a plurality of instruction sets, each instruction set associated with a component to be printed. Accordingly, the system 10 may be configured to print various components. It should be noted that the fusing trajectory of the fusing mechanism 20 will be different and correspond to the component to be printed.However, the operation and movement of the outlet 24 relative to the melt path is essentially the same for all of the different components. That is, the outlet 24 moves forward as the melt path of the melting mechanism 20 moves in the first direction "1D," keeping the outlet 24 upstream of the melt path of the melting mechanism 20.

[0048] In one configuration, the system 10 may include an inlet 36 configured to receive the gas and particles blown through the outlet 24 and direct the gas and blown particles out of the chamber 12. The inlet 36 may be disposed on the second wall 16b and is generally coplanar with the outlet 24. In one aspect, the inlet 36 is connected to a trap (not shown), which may include filters and the like, for capturing the particles. In another aspect, the inlet 36 is connected to a negative pressure 38 for drawing the gas and particles in the cloud generated by the melting process out of the chamber 12. The negative pressure 38 may be configured to sufficiently draw the particles in the cloud into the inlet 36 without dislodging the particles in the particle layer 18.Accordingly, the negative pressure 38 can produce a flow rate that is substantially equal to or less than the flow rate of the blower 26.

[0049] As in Fig. 5, the inlet 36 may be attached to one end of the chamber 12 and spaced from the outlet 24. For example, in configurations where the melt path of the jet begins at the second wall 16b and moves toward the first wall 16a, the inlet 36 may be formed on the second wall 16b so that it is in a fixed position. Thus, the distance between the inlet 36 and the outlet 24 increases as the outlet 24 is moved during the melting process. In one configuration, the inlet 36 may be an elongated slot 40 formed on the second wall 16b and generally coplanar with the outlet 24. In another aspect, the inlet 36 may be sized to extend across the width of the chamber 12 and to be substantially the same length as the outlet 24.

[0050] In Fig. 7 describes the functioning of system 10. Fig. Figure 7 shows the system 10 in an initial stage of a first pass of the melting mechanism 20. The dispensing mechanism 22 has dispensed a layer of the particles 18 to be melted prior to the first pass. As used herein, a "pass" refers to the movement of the jet from one end of the chamber 12 to the other end, e.g., from the first wall 16a to the second wall 16b, indicating the completion of a melting process to form a layer of the printed component. The system 10 performs numerous passes to complete the printed component layer by layer, and the dispensing mechanism 22 dispenses another layer of particles 18 after each pass until the component is complete.

[0051] The melting mechanism 20 generates a jet at a predetermined location on the particle layer 18 to initiate the melting path. The melting path moves in the first direction "1D" toward the other end of the chamber 12 when the particles have been melted within a range defined by the width and length of the chamber 12. The blower 26 is actuated during the melting process, and the particles in the cloud created by the melting process are blown out of the jet path along the second direction "2D," which is opposite to the first direction "1D." As the melting path moves along the first direction "1D," the outlet 24 is also moved. The movement of the jet and the outlet 24 is controlled by the controller 34, which can maintain a predetermined distance between the melting path of the jet and the outlet 24 to prevent the outlet 24 from obscuring the path of the jet.

[0052] The inlet 36 can be Fig. 8 - 10 can be movable relative to the outlet 24. In such a case, the inlet 36 is a separate component with a conduit 42 that communicates with a space outside the chamber 12. The outlet 24 is designed to direct gas into the inlet 36, thereby carrying the particles of a cloud out of the chamber 12. The inlet 36 can have the same shape as the outlet 24, as in Fig. 8 shown.

[0053] The inlet 36 and the outlet 24 are mounted on the rail system 30. Fig. 9 shows an aspect of the rail system 30 configured to supply gas to the outlet 24, with the dispensing mechanism 22 disposed within the inlet 36. In such a case, the rail system 30 includes a pair of rails 30a, 30b, each having a conduit 44 for directing gas from a fan 26 to the outlet 24. The fan 26 may be disposed within the rail 30a, 30b or outside the rail 30a, 30b. The dispensing mechanism 22 is disposed within the inlet 36 and may include a distributor (not shown) configured to disperse the particulate layer 18 as the inlet 36 moves along the first direction "1D."

[0054] The inlet 36 is spaced far enough from the outlet 24 to accommodate the melt path of the jet. The inlet 36 may be fixed in position relative to the outlet 24 or movable with respect to the outlet 24. In either aspect, the inlet 36 and the outlet 24 are movable in the first direction "1D" along the rail system 30. As the jet moves along the length of the chamber 12 from one end to the other, the inlet 36 and the outlet 24 shift to accommodate the melt path of the jet, as shown in the Fig. 9 and Fig. 10. As the jet fuses the particles, a cloud of particles is created, and the particles in the cloud are blown into the inlet 36 by the gas flowing from the outlet 24. The path of the jet is relatively unobstructed because any fused particles in the cloud are pulled out of the chamber 12, thereby reducing defects in the printed component.

[0055] In Fig. 9, the area between the inlet 36 and the outlet 24 is designated for the melt path. It should be noted that the melt path does not need to be linear. That is, the melt path does not need to extend from one side of the chamber 12 to the other side of the chamber 12 or from the outlet 24 to the inlet 36, but rather may extend across a width and a length of the particle layer 18. For example, in melting mechanisms 20 having multiple jet generators 20a, 20b, the melt path of each of the jet generators 20a, 20b may begin at different locations in the area between the inlet 36 and the outlet 24, and once the jet generator has completed its melt path, the outlet 24 and the inlet 36 are advanced along the first direction "1D." In one aspect, the inlet 36 is in a fixed position relative to the outlet 24, such that the inlet 36 and the outlet 24 move together.In another aspect, the inlet 36 and the outlet 24 may be movable relative to each other, as shown in FIG. Fig. 9. In such an aspect, the outlet 24 may be advanced in the first direction "1D" before the inlet 36 is advanced, thereby increasing the distance between the inlet 36 and the outlet 24.

[0056] As in Fig. As shown in Figure 10, the controller 34 may be operated to control the melting mechanism 20, the dispensing mechanism 22, and the movement mechanism 32 to coordinate the movement of the outlet 24 and the inlet 36 relative to the melting path of the jet. Specifically, the controller 34 may be configured to actuate the movement mechanism 32 to move the outlet 24 and the inlet 36 between a start position ("SP") and an end position ("EP") as the melting mechanism 20 traverses the melting path. Fig. 10 shows the outlet 24 and the inlet 36 moved from the starting position "SP" to the ending position "EP" along the first direction "1D." The controller 34 moves the outlet 24 and the inlet 36 in coordination with the melting path so that the outlet 24 remains upstream of the jet and the inlet 36 remains downstream of the jet. Thus, the particles in the cloud are blown into the inlet 36. The controller 34 can be further configured so that when the outlet 24 reaches the ending position "EP," the jet returns to the starting position "SP" after the melting mechanism 20 has completed the melting path. The controller 34 is further configured to actuate the discharge mechanism 22 to discharge another layer of particles 18 into the chamber 12.

[0057] In aspects where the dispensing mechanism 22 is a conveyor container, as in Fig. As illustrated in Figure 7, the controller 34 may actuate the conveyor hopper to discharge the particle layer 18 after the outlet 24 has reached the end position "EP" or after the outlet 24 and inlet 36 have returned to the start position "SP." After the particle layer 18 has been discharged, the controller 34 actuates the melting mechanism 20 to execute the melting path, which may be different from the previous melting path, and actuates the outlet 24 and inlet 36 in coordination with the advancement of the melting path along the first direction "1D." This process is repeated until the component is completed.

[0058] In aspects where the dispensing mechanism 22 is disposed within the inlet 36, the controller 34 may be configured to actuate the dispensing mechanism 22 to dispense the layer of particles 18 as the inlet 36 moves along the first direction "1D." Accordingly, a layer of particles 18 is dispensed as the inlet 36 is advanced. Alternatively, the controller 34 may be configured to actuate the dispensing mechanism 22 as the inlet 36 returns from the end position "EP" to the start position "SP."

[0059] In relation to Fig. 11, in one aspect of the system 10, the inlet 36 may be movable with respect to the outlet 24. In such an aspect, the outlet 24 is fixed within the chamber 100. For illustrative purposes, the outlet 24 is shown fixed to the second sidewall 16b. The outlet 24 is configured to blow an inert gas into the chamber 100 in a direction corresponding to the first direction "1D". The inlet 36 may include a slot 28 for drawing air into the inlet 36 in a direction corresponding to the first direction "1D". The inlet 36 is fluidly connected to a vacuum 38 that can draw the air into a space outside the chamber 12.

[0060] The inlet 36 is mounted on the rail system 30 and between the two rails 30a, 30b, each of which includes a conduit 44 for conducting gas from the inlet 36. The blower 26 can be located and mounted inside the rail 30a, 30b or outside the rail 30a, 30b. The dispensing mechanism 22 is located in the inlet 36 and can include a distributor (not shown) configured to distribute the particle layer 18 as the inlet 36 moves along the first direction "1D." As the jet fuses the particles, a cloud of particles is created, and the particles in the cloud are drawn into the inlet 36 by the negative pressure 38. The path of the jet is relatively unobstructed because any fused particles in the cloud are pulled out of the chamber 12, reducing defects in the printed component.

[0061] The melt path is located in the area between the inlet 36 and the outlet 24. It should be noted that the melt path does not have to be linear. That is, the melt path does not have to run from one side of the chamber 12 to the other side of the chamber 12 or from the outlet 24 to the inlet 36, but can extend across a width and a length of the particle layer 18. For example, in melting mechanisms 20 with multiple jet generators 20a, 20b, the melt path of each of the jet generators 20a, 20b can begin at different locations in the area between the inlet 36 and the outlet 24, and once the jet generator has completed its melt path, the inlet 36 is advanced along the first direction "1D." Thus, Fig. 11 illustrates an aspect in which the distance between the inlet 36 and the outlet 24 increases as the inlet 36 moves along the first direction “1D”.

[0062] According to Fig. 12, in one aspect of the system 10, the inlet 36 and the outlet 24 are movable along the rail system 30 in the first direction "1D." In such an aspect, the inlet 36 and the outlet 24 are also movable relative to each other to enable the melt path. As in the Fig. In the aspect shown in Figure 11, the vacuum 38 is coupled to the inlet 36 and configured to draw air into the inlet 36 along the first direction "1D." The outlet 24 is configured to inject inert gas into the chamber 12 in the first direction "1D."

[0063] In Fig.13 illustrates a method 200 for performing additive manufacturing. In step 202, the method includes melting particles in a particle layer 18 with a beam. The beam moves along a melt path from one end of the chamber 12 to another end of the chamber 12 in a first "1D" direction. The melt path of particles in a particle layer 18 with a beam can be performed using a laser beam or an electron beam. The melt path can extend over both a portion of the length of the chamber 12 and a portion of the width of the chamber 12, depending on the design of the component to be printed.

[0064] In step 204, the method includes providing an outlet 24 for blowing gas in a second direction "2D" opposite the first direction "1D" and moving the outlet 24 along the first direction "1D." The gas may be an inert gas configured to cause minimal disruption to the jet. The outlet 24 may extend across the width of the chamber 12 and may be moved along a rail 30a, 30b extending the length of the chamber 12. Steps 102 and 104 may, of course, be performed simultaneously.

[0065] In step 206, the method includes maintaining the outlet 24 upstream of the melt path to blow air downstream of the melt path. Accordingly, the outlet 24 is moved as the jet generated by the melting mechanism 20 moves along the first direction "1D." Note that the outlet 24 is not moved immediately or simultaneously with the movement of a jet in the first direction "1D," but only when the jet is at a predetermined distance from the outlet 24. For example, the outlet 24 may be moved in the first direction "1D" when the jet approaches within 50 mm of the outlet 24.

[0066] In step 208, the method may include providing an inlet 36 configured to draw air from inside the chamber 12 to an environment outside the chamber 12. The inlet 36 may be located a predetermined distance from the outlet 24 to facilitate the melt path. The inlet 36 may be a tubular or cuboid-shaped structure extending across the width of the chamber 12. The inlet 36 includes a slot for receiving the particles expelled from the outlet 24.

[0067] The method may include moving the inlet 36 relative to the outlet 24 by a controller 34, wherein the controller 34 moves the inlet 36 and the outlet 24 to accommodate or enable the melt trajectory of the jet. The controller 34 may be further configured to move the outlet 24 and the inlet 36 between a start position "SP" and an end position "EP." Printing begins at the start position "SP," and a first layer of the component is printed when the outlet 24 reaches the end position "EP." The method may include the controller 34 maintaining the outlet 24 upstream of the jet and the inlet 36 downstream of the jet while the jet moves along the melt trajectory and returning the jet to the starting position when the jet has completed the melt trajectory. The method may include adding another layer of particles 18 to be printed.This can be achieved by providing the inlet 36 with a dispensing mechanism 22 that dispenses particles when the inlet 36 is moved from the start position "SP" to the end position "EP." In aspects where the dispensing mechanism 22 is a conveyor hopper, the particles can be dispensed after the outlet 24 has reached the end position "EP" or the start position "SP."

[0068] Accordingly, a system and method for additive manufacturing includes an outlet movable in the first "1D" direction and maintaining the outlet upstream of the beam. The outlet is configured to blow air in a second "2D" direction opposite the first "1D" direction, thereby blowing particles in a cloud out of the beam path of the melting mechanism. Furthermore, any particles in the cloud that are melted are pulled out of the chamber, reducing the imperfection of the printed component. Because the outlet is movable along the chamber, the size of the chamber is unlimited, and thus the size of the component to be printed by the additive manufacturing process.

[0069] A number of implementations have been described. However, it should be understood that various changes may be made without departing from the spirit and scope of the disclosure. Accordingly, other embodiments are also within the scope of the following claims.

[0070] The foregoing description is for purposes of illustration and description. It is not intended to be exhaustive or limiting of the disclosure. Individual elements or features of a particular configuration are generally not limited to that particular configuration, but are optionally interchangeable and may be used in a selected configuration even if not specifically shown or described. The same may also be varied in many respects. Such variations are not to be considered as departing from the disclosure, and all such changes are intended to be included within the scope of the disclosure.

Claims

[1] A system for additive manufacturing, the system comprising a chamber containing a layer of particles, the system comprising: a melting mechanism that emits a jet for melting particles in the particle layer, the melting mechanism being configured to move the jet in a melting path, the melting path extending from one end of the chamber to another end of the chamber in a first direction; an outlet movable in the first direction and configured to blow air in a second direction, the second direction being opposite to the first direction; and a controller configured to move the outlet in the first direction and maintain the outlet upstream of the jet, the outlet blowing the particles away from the particle bed in a cloud of particles. [2] The system of claim 1, wherein the beam is a laser beam or an electron beam. [3] The system of claim 1, wherein the outlet extends along a width of the chamber. [4] The system of claim 1, further comprising a rail, the rail extending along a length of the chamber, the outlet being movably disposed along the rail. [5] The system of claim 1, further comprising an inlet configured to draw air from inside the chamber to an environment outside the chamber. [6] The system of claim 5, wherein the inlet is spaced from the outlet. [7] The system of claim 5, wherein the inlet extends along a width of the chamber. [8] The system of claim 6, wherein the inlet is movable relative to the outlet to adjust the melt trajectory of the jet. [9] The system of claim 8, wherein the controller is configured to move the outlet and the inlet between a start position and an end position. [10] The system of claim 9, wherein the controller is configured to maintain the outlet upstream of the jet and the inlet downstream of the jet while the jet moves along the melt path and to return the jet to the home position when the jet has completed the melt path.

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