阅读说明：本技术 用于分隔增材制造系统的构建室的间隔件导流器 (Spacer deflector for partitioning build chamber of additive manufacturing system ) 是由 穆罕默德·穆尼尔·沙拉贝 于 2019-08-21 设计创作，主要内容包括：本公开涉及一种增材制造(AM)系统(10)的制造和使用,该增材制造(AM)系统采用设置或形成在限定AM系统(10)的室(32)的壳体(30)内的间隔件导流器(140)。间隔件导流器(140)可将室(32)内的气流(252、262)的各个部分引导至相应的排气通道(220、224)。例如,结合壳体(30)的部分,间隔件导流器(140)可以限定主排气通道(220),该主排气通道(220)在室(32)和形成在壳体(30)的下游端(204)中的气体出口(290)之间延伸。另外,可以在室(32)和间隔件导流器(140)的后表面(176)之间限定旁路排气通道(224),以将室(32)的上部(244)流体地联接到主排气通道(220)。(The present disclosure relates to the manufacture and use of an Additive Manufacturing (AM) system (10) that employs a spacer deflector (140) disposed or formed within a housing (30) defining a chamber (32) of the AM system (10). The spacer deflector (140) may direct respective portions of the airflow (252, 262) within the chamber (32) to the respective exhaust passages (220, 224). For example, in conjunction with a portion of the housing (30), the spacer deflector (140) may define a main exhaust passage (220), the main exhaust passage (220) extending between the chamber (32) and a gas outlet (290) formed in the downstream end (204) of the housing (30). Additionally, a bypass exhaust passage (224) may be defined between the chamber (32) and a rear surface (176) of the spacer deflector (140) to fluidly couple an upper portion (244) of the chamber (32) to the main exhaust passage (220).)

1. An Additive Manufacturing (AM) system (10), comprising:

a housing (30), the housing (30) defining a chamber (32), wherein a lower portion (248) of the chamber (32) includes a build platform (40) disposed therein, the build platform (40) configured to receive a powder material (46);

a gas inlet system (240), the gas inlet system (240) coupled to a first sidewall (100) of the housing (30) and configured to direct one or more gas flows (252, 262) through the chamber (32);

a gas outlet (290) defined in a second sidewall (102) of the housing (30), the second sidewall (102) disposed opposite the first sidewall (100), wherein the gas outlet (290) is configured to discharge the one or more gas flows (252, 262) from the chamber (32);

a spacer deflector (140), the spacer deflector (140) disposed within the chamber (32) and configured to direct the one or more air flows (252, 262) around the spacer deflector (140);

a main exhaust passage (220), the main exhaust passage (220) defined between the first surface (154) of the spacer deflector (140) and the housing (30), wherein the main exhaust passage (220) is configured to direct a first portion (356) of the one or more gas flows (252, 262) from the lower portion (248) of the chamber (32) into the gas outlet (290); and

a bypass exhaust passage (224) defined between the second surface (160) of the spacer deflector (140) and the housing (30), wherein the bypass exhaust passage (224) is configured to direct a second portion (354) of the one or more gas flows (252, 262) from an upper portion (244) of the chamber (32) to join the first portion (356) and the second portion (354) of the one or more gas flows (252, 262) upstream of the gas outlet (290).

2. The AM system (10) of claim 1, wherein the spacer deflector (140) includes a third surface (170) upstream of the first surface (154) and the second surface (160), wherein the third surface (170) is inclined at a guide angle (344) relative to the first sidewall (100), and wherein the third surface (170) is configured to direct at least a portion of the first portion (356) of the one or more airflows (252, 262) into the main exhaust channel (220).

3. The AM system (10) according to claim 2, wherein the conduction angle (344) is between about 10 degrees and about 60 degrees.

4. The AM system (10) of claim 2, comprising an energy generation system (50), the energy generation system (50) configured to apply a focused energy beam (52) to the powder material (46) received by the build platform (40), wherein the steering angle (344) is substantially parallel to a beam angle (62) of the focused energy beam (52).

5. The AM system (10) according to any preceding claim, wherein the housing (30) comprises:

a third sidewall (106), the third sidewall (106) extending between a first edge (108) of the first sidewall (100) and a first edge (110) of the second sidewall (102); and

a fourth sidewall (112), the fourth sidewall (112) extending between a second edge (114) of the first sidewall (100) and a second edge (116) of the second sidewall (102), wherein the bypass exhaust channel (224) includes a width (126), the width (126) defined between the first edge (110) of the second sidewall (102) and the second edge (116) of the second sidewall (102).

6. The AM system (10) according to any preceding claim, wherein an upstream portion (422) of the bypass exhaust channel (224) includes a tapered neck (410), the tapered neck (410) narrowing along a flow direction of the bypass exhaust channel (224) along the second portion (354) of the one or more gas flows (252, 262).

7. An AM system (10) according to any preceding claim comprising:

an interconnecting exhaust passage (460), the interconnecting exhaust passage (460) extending through the spacer deflector (140), wherein the interconnecting exhaust passage (460) is configured to direct a third portion of the one or more airflows (252, 262) from a middle portion (490) of the chamber (32) and join the third portion with the second portion (354) of the one or more airflows (252, 262) in the bypass exhaust passage (224), wherein the interconnecting exhaust passage (460) is positioned at a vertical distance between the main exhaust passage (220) and the bypass exhaust passage (224).

8. The AM system (10) according to any preceding claim, wherein the gas inlet system (240) comprises:

an upper gas inlet (250), the upper gas inlet (250) being defined in the first sidewall (100) of the housing (30), wherein the upper gas inlet (250) is configured to direct an upper gas flow (252) of the one or more gas flows (252, 262) through the chamber (32); and

a lower gas inlet (260) defined in the first sidewall (100) and positioned a vertical distance below the upper gas inlet (250), wherein the lower gas inlet (260) is configured to direct a lower gas flow (262) of the one or more gas flows (252, 262) toward the build platform (40).

9. The AM system (10) of claim 8, comprising one or more gas delivery devices (256, 276), the one or more gas delivery devices (256, 276) coupled to the upper and lower gas inlets (250, 260) and configured to adjust one or more flow characteristics of the upper and lower gas flows (252, 262), wherein the one or more gas delivery devices (256, 276) are configured to supply the upper and lower gas flows (252, 262) at a flow rate ratio of the upper gas flow (252) to the lower gas flow (262), the flow rate ratio of the upper gas flow (252) to the lower gas flow (262) being about 3: 1 and about 1: 1, or about 2: 1.

10. The AM system (10) according to any preceding claim comprising a laser window (56), the laser window (56) formed within a top wall (54) of the housing (30), wherein the top wall (54) extends between an upper edge of the first sidewall (100) and an upper edge of the second sidewall (102), wherein the laser window (56) protrudes from the top wall (54) into the chamber (32) such that a portion of the one or more airflows (252, 262) impinge on the laser window (56) and are directed into the bypass exhaust channel (224).

11. An AM system (10) according to any preceding claim comprising:

a sensor (380), the sensor (380) fluidly coupled to the bypass exhaust passage (224); and

a controller (20), the controller (20) communicatively coupled to the sensor (380) and a gas inlet system (240), the gas inlet system (240) configured to provide the one or more gas flows (252, 262) to the chamber (32), wherein the controller (20) is configured to instruct the gas inlet system (240) to adjust a flow rate of the one or more gas flows (252, 262) in response to receiving a signal from the sensor (380) indicating that a concentration of particles exceeds a particle concentration threshold.

12. A method (550) of operating an Additive Manufacturing (AM) system (10), comprising:

depositing (552) a bed of powder material (46) on a build platform (40) located within a lower portion (248) of a chamber (32) defined by a housing (30);

supplying (554) one or more gas streams (252, 262) into the chamber (32);

directing (556) a first portion (356) of the one or more gas flows (252, 262) along a main exhaust passage (220) defined between the housing (30) and a lower surface (154) of the spacer deflector (140) disposed within the chamber (32), wherein the main exhaust passage (220) fluidly couples the lower portion (248) of the chamber (32) to a gas outlet (290); and

directing (558) a second portion (354) of the one or more air flows (252, 262) along a bypass exhaust channel (224) defined between the housing (30) and an upper surface (160) of the spacer deflector (140), wherein the bypass exhaust channel (224) fluidly couples an upper portion (244) of the chamber (32) to the main exhaust channel (220).

13. The method (550) according to claim 12, comprising:

receiving (560), via a sensor (380) fluidly coupled to the bypass exhaust passage (224), feedback indicative of an operating parameter of the second portion (354) of the one or more airflows (252, 262) via a control system (374) of the AM system (10);

determining (562), via the control system (374), whether the operating parameter is outside an operating parameter threshold; and

adjusting (564), via the control system (374), a flow rate of the one or more airflows (252, 262) supplied into the chamber (32) in response to determining that the operating parameter is outside of the operating parameter threshold.

14. The method (550) of claim 13, wherein the operating parameter comprises a flow rate of the second portion (354) of the one or more gas flows (252, 262), and the operating parameter threshold comprises a flow rate threshold.

15. The method (550) of claim 13, wherein the operating parameter comprises a particle concentration of the second portion (354) of the one or more gas flows (252, 262) and the operating parameter threshold comprises a particle concentration threshold, and wherein the method comprises increasing the flow rate of the one or more gas flows (252, 262) in response to determining that the particle concentration is above the particle concentration threshold.

Technical Field

The subject matter disclosed herein relates generally to additive manufacturing systems, and more particularly, to Direct Laser Sintering (DLS) or Direct Laser Melting (DLM) systems that employ focused energy to selectively melt a powder material to produce an object.

Background

In contrast to subtractive manufacturing methods, which selectively remove material from an original form to make an object, Additive Manufacturing (AM) processes typically involve the accumulation of one or more materials to make a net-shape or near-net-shape object. While "additive manufacturing" is an industry standard term (ASTM F2792), it encompasses various manufacturing and prototyping techniques known by various names, including free-form fabrication, 3D printing, and rapid prototyping/tooling. A particular type of AM process uses a focused energy source (e.g., electron beam, laser beam) to sinter or melt a powder material deposited on a build platform within a chamber, thereby producing a solid three-dimensional object in which particles of the powder material are bonded together.

Laser sintering/melting, as used in Direct Laser Sintering (DLS) and/or Direct Laser Melting (DLM), is a common industrial term used to refer to methods for producing three-dimensional (3D) objects by sintering or melting fine powders using energy beams. In particular, laser sintering/fusing techniques typically require a laser beam to be selectively directed onto a controlled amount of powder (e.g., a powder bed) on a substrate to form a fused particulate or fused material layer thereon. When the laser beam interacts with the powder bed, smoke and/or particulate matter (e.g., condensate, spatter) may be generated within the chamber. Smoke and/or particulate matter may be detrimental to the quality of the resulting object. For example, aerosol and/or particulate matter within the chamber can interfere with the laser beam and reduce its energy or intensity before it reaches the powder bed. As another example, fumes and/or particulate matter may deposit on the powder bed and may become incorporated into the resulting object.

In certain laser sintering/melting (or DLS/DLM) systems, a gas stream is introduced into the chamber to flow along the build platform in an effort to remove fumes and/or particulate matter and prevent deposition. However, because the volume of the chamber may be large to accommodate components of the DLS/DLM system, the amount of airflow sufficient to remove smoke and/or particulate matter from the chamber may be large. As such, replacing the airflow or reconditioning the airflow downstream of the chamber to remove smoke and/or particulate matter from the airflow before the airflow is returned to the chamber can be an expensive process. Therefore, replacing or re-regulating the airflow directed through the large volume manufacturing chamber may increase the operating cost and/or material cost of the DLS/DLM system.

Disclosure of Invention

In one embodiment, an Additive Manufacturing (AM) system includes a housing defining a chamber. The lower portion of the chamber includes a build platform disposed therein, the build platform configured to receive the powder material. The AM system includes a gas inlet system coupled to the first sidewall of the housing and configured to direct one or more gas flows through the chamber. The AM system includes a gas outlet defined in a second sidewall of the housing, the second sidewall being disposed opposite the first sidewall. The gas outlet is configured to discharge one or more gas streams from the chamber. The AM system also includes a spacer deflector disposed within the chamber and configured to direct one or more air flows around the spacer deflector. The AM system includes a main exhaust passage defined between a first surface of the spacer deflector and the housing. The main exhaust passage is configured to direct a first portion of the one or more gas flows from a lower portion of the chamber into the gas outlet. The AM system further includes a bypass exhaust passage defined between the second surface of the spacer deflector and the housing. The bypass exhaust passage is configured to direct a second portion of the one or more gas flows from the upper portion of the chamber to combine the first and second portions of the one or more gas flows upstream of the gas outlet.

In another embodiment, a method for operating an Additive Manufacturing (AM) system includes depositing a bed of powder material on a build platform located within a lower portion of a chamber defined by a housing. The method includes supplying one or more gas streams into the chamber. The method includes directing a first portion of one or more air flows along a main exhaust passage defined between a housing and a lower surface of a spacer deflector disposed within a chamber. The main exhaust channel fluidly couples a lower portion of the chamber to the gas outlet. The method includes directing a second portion of the one or more gas flows along a bypass exhaust passage defined between the housing and an upper surface of the spacer deflector. A bypass exhaust passage fluidly couples an upper portion of the chamber to the main exhaust passage.

In yet another embodiment, an Additive Manufacturing (AM) system includes a housing defining a chamber. The chamber is configured to receive one or more gas flows therein. The AM system includes a build platform disposed within a lower portion of the chamber and configured to receive a bed of powder material. The AM system includes a gas outlet defined in a first sidewall of the housing. The gas outlet is configured to discharge one or more gas streams from the chamber. The AM system also includes a spacer deflector configured to direct a first portion of the one or more air flows below the spacer deflector and configured to direct a second portion of the one or more air flows above the spacer deflector. The AM system includes a main exhaust passage defined between a lower surface of the spacer deflector and the housing. The main exhaust passage is configured to direct a first portion of the one or more gas flows into the gas outlet. Additionally, the AM system includes a bypass exhaust passage defined between an upper surface of the spacer deflector and the housing. The bypass exhaust passage is configured to introduce a second portion of the one or more gas flows into the first portion of the one or more gas flows at an injection point located along a length of the main exhaust passage upstream of the gas outlet.

Drawings

These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

fig. 1 is a schematic diagram of an embodiment of an Additive Manufacturing (AM) system having a manufacturing chamber according to the present embodiments;

fig. 2 is a schematic perspective view illustrating an embodiment of a manufacturing chamber of the AM system of fig. 1 including a spacer deflector disposed therein according to the present embodiments;

fig. 3 is a schematic cross-sectional view illustrating airflow of an embodiment of the AM system of fig. 2 having a spacer deflector having a first guide angle for guiding airflow according to the present embodiment;

fig. 4 is a partial schematic cross-sectional view illustrating airflow of an embodiment of the AM system of fig. 2 having a spacer deflector with a second guide angle for guiding airflow according to the present embodiment;

FIG. 5 is a partial schematic cross-sectional view illustrating airflow of an embodiment of the AM system of FIG. 2 having a bypass exhaust passage with a tapered neck formed by a spacer deflector, according to the present embodiments;

FIG. 6 is a partial schematic cross-sectional view illustrating airflow of an embodiment of the AM system of FIG. 2 having a reduced laser window and bypass vent channel formed by a spacer deflector, according to the present embodiments;

FIG. 7 is a partial schematic cross-sectional view illustrating airflow of an embodiment of the AM system of FIG. 2 having a plurality of interconnected channels formed by spacer deflectors and coupled to a bypass exhaust channel, according to the present embodiments; and

fig. 8 is a flowchart representing an embodiment of a process for operating the AM system of fig. 2 according to the present embodiment.

Detailed Description

One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

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" is not meant to be exclusive and means that at least one of the referenced components is present, and includes examples in which combinations of the referenced components may be present, unless the context clearly dictates otherwise. As used herein, the term "uniform gas flow" means that the flow rate of the gas flow does not vary significantly across the width and/or length of the path of the gas flow such that the flow rate is within + -10%, + -5%, or + -1% of the flow rate at another location. As used herein, the term "additive manufacturing" or "AM" relates to any suitable laser or electron beam sintering/melting additive manufacturing technique, including but not limited to: direct metal laser melting, direct metal laser sintering, direct metal laser deposition, laser engineering net shape forming, selective laser sintering, selective laser melting, selective heat sintering, fused deposition modeling, hybrid systems, or combinations thereof.

The present disclosure generally includes systems and methods for fabricating objects using laser sintering/melting based additive manufacturing methods. As mentioned, with such additive manufacturing techniques, as the laser beam sinters or melts the powder bed within the enclosed manufacturing chamber, fumes and/or particulate matter (e.g., condensate, spatter), collectively referred to herein as "particulates," can accumulate or build up within the chamber. To effectively remove these particles, which may interfere with the fabrication process, a significant flow rate (e.g., mass flow rate, volume flow rate) of gas flow may be directed through the chamber. As such, it may be desirable to partition the chamber to reduce the volume of the chamber to a smaller gas volume without affecting the efficiency of the manufacturing process. Further, the present techniques provide additional flow paths between portions of the chamber other than the stagnation portion and the gas outlet to enable lower gas flow rates to be utilized during operation.

As discussed in detail below, some embodiments of the present disclosure include an Additive Manufacturing (AM) system that employs a spacer deflector disposed or formed within a housing that defines a chamber of the AM system. The spacer deflector is typically a plug or baffle that fits within the chamber to direct various portions of the airflow therein to the respective exhaust passages. For example, in combination with portions of the housing, the spacer deflector defines a main exhaust passage extending between a build platform within the chamber and a gas outlet formed in the downstream end of the housing. In addition, a bypass exhaust passage is defined between the housing and the rear surface of the spacer deflector to fluidly couple an upper portion of the chamber to the main exhaust passage. As discussed, the bypass exhaust passage may include physical features (e.g., a tapered neck, additional interconnecting passages extending between the chamber and the bypass exhaust passage) to further facilitate removing a portion of the airflow from the upper portion of the chamber that may circulate within the chamber. Thus, the addition of a spacer flow director may advantageously reduce the amount of gas in the chamber and/or reduce the recirculation of particles inside the chamber to enable the AM system to utilize reduced gas flow rates for fabrication processes. These and other features are described below with reference to the drawings.

Fig. 1 illustrates an example embodiment of an AM system 10 (e.g., a laser sintering/melting AM system 10) for producing an article or object using a focused energy source or beam. For ease of discussion, the AM system 10 and its components will be described with reference to an x-axis or direction 12, a y-axis or direction 14, and a z-axis or direction 16. In the illustrated embodiment, the AM system 10 includes a controller 20, the controller 20 having a memory circuit 22 that stores instructions (e.g., software, applications) and a processing circuit 24 programmed or designed to execute the instructions to control various components of the AM system 10. The AM system 10 includes a housing 30, the housing 30 defining a fabrication chamber 32 (also referred to herein as chamber 32), the fabrication chamber 32 defining an interior volume 34. Chamber 32 is sealed to contain an inert atmosphere and to protect the build process from the ambient atmosphere 36 outside of housing 30. The AM system 10 includes a build platform 40, with the build platform 40 disposed on a base or bottom wall 42 of the housing 30 within the chamber 32. In some embodiments, build platform 40 may have a height of about 0.01 square meters (m)²) To about 1.5m²A working area (e.g., a top surface of build platform 40) in between. The AM processed article or object is fabricated on build platform 40 as described below.

The AM system 10 includes a powder application device 44, which powder application device 44 may be disposed within the chamber 32 to deposit a quantity of powder material (e.g., a layer or bed of powder material) onto the build platform 40. The powder material deposited on the build platform 40 generally forms a powder bed 46. The powdered material may include, but is not limited to, polymers, plastics, metals, ceramics, sand, glass, waxes, fibers, biological matter, composites, or mixtures of these materials. These materials may be used in a variety of forms suitable for a given material and process, including, for example, solids, powders, sheets, foils, tapes, filaments, pellets, strands, mists, and combinations of these forms.

AM system 10 further includes an energy generation system 50, which energy generation system 50 may be disposed inside or outside of chamber 32 to generate and selectively direct a focused energy beam 52 (e.g., a laser beam) onto at least a portion of powder bed 46 disposed on build platform 40. For the embodiment shown in fig. 1, the energy generating system 50 is disposed adjacent a top or top wall 54 of the housing 30 opposite the base or bottom wall 42. For the embodiment shown, the focused energy beam 52 enters the chamber 32 through a window or laser window 56 disposed in the top wall 54. Focused energy beam 52 is directed onto build platform 40 at any suitable angle relative to a vertical axis 60 extending along z-axis 16 between energy generation system 50 and build platform 40, e.g., an angle ranging from 0 degrees to a beam angle 62 relative to vertical axis 60, which is defined between vertical axis 60 and a maximum offset axis 64 extending between energy generation system 50 and an edge 66 of build platform 40, e.g., 20 °, 25 °, 30 °, 35 °, 40 °, 45 °, 50 °, etc. Thus, depending on the desired article geometry, the powder bed 46 disposed on the build platform 40 is selectively subjected to the focused energy beam 52 at any suitable angle in a selective manner controlled by the controller 20. In some embodiments, the energy generation system 50 includes a focused energy source for generating a focused energy beam 52. In some embodiments, the focused energy source comprises a laser source and the focused energy beam 52 is a laser beam. In some embodiments, the laser source comprises a pulsed laser source that generates a pulsed laser beam. In contrast to continuous laser radiation, pulsed laser beams are not emitted continuously, but in pulses (for example pulses of finite duration separated by a time interval). In some embodiments, the energy generation system 50 includes a plurality of focused energy sources, each selectively illuminating the powder bed 46 with a focused energy beam 52.

AM system 10 includes a positioning system 70 (e.g., a gantry or other suitable positioning system), which may be disposed within chamber 32. The positioning system 70 may be any multi-dimensional positioning system, such as a delta robot, a cable robot, a robotic arm, or other suitable positioning system. The positioning system 70 may be operably coupled to the powder application device 44, the energy generation system 50, the build platform 40, or a combination thereof. Positioning system 70 may move powder application device 44, energy generation system 50, build platform 40, or a combination thereof relative to one another in any of x-direction 12, y-direction 14, z-direction 16, or a combination thereof.

As will be discussed in more detail in fig. 2, the AM system 10 is also designed to supply an inlet gas stream 80 (e.g., a total gas stream, a single gas stream, upper and lower gas streams) into the chamber 32 and discharge an exhaust gas stream 82 from the chamber 32. For example, for embodiments of AM system 10 in which inlet gas flow 80 comprises an upper gas flow and a lower gas flow provided into chamber 32, exhaust gas flow 82 discharged from chamber 32 comprises the upper gas flow, the lower gas flow, and most of any particles generated when focused energy beam 52 is applied to selectively melt or sinter powder bed 46 during formation of the desired article.

Chamber 32 is formed to have sufficient dimensions to enable multiple components disposed within chamber 32 and/or coupled to chamber 32 to cooperate to form a desired article. Thus, these components may utilize a significant portion of the interior volume 34 of the chamber 32 and provide the aforementioned airflow at a sufficient flow rate to remove particles from the chamber 32. As described below, to seal off or enclose unused portions of the chamber 32 and reduce the gas volume of the chamber 32 without interfering with the manufacturing process, the AM system 10 further includes a spacer deflector disposed within the housing 30. The spacer deflector may selectively direct a first or main portion of the inlet gas flow 80 within the chamber 32 to the gas outlet and a second or auxiliary portion of the inlet gas flow 80 from another portion of the chamber 32 to join the main portion. By restricting the airflow through portions of the chamber 32 not occupied by other components of the AM system 10, the spacer deflector is able to significantly reduce the working volume of the chamber 32. Moreover, the reduced working volume is associated with substantially reduced airflow requirements and costs associated with recirculating or otherwise replacing the airflow within the AM system 10.

Fig. 2 is a schematic perspective view illustrating an embodiment of the chamber 32 of the AM system 10 according to the present embodiment. As shown, to enclose the interior volume 34 of the chamber 32, the housing 30 of the present embodiment includes a front wall 100, the front wall 100 being spaced apart from a rear wall 102 by a chamber length 104 defined along the x-axis 12. In addition, a first side wall 106 of the housing 30 extends between a first edge 108 of the front wall 100 and a first edge 110 of the rear wall 102, and a second side wall 112 of the housing 30 extends between a second edge 114 of the front wall 100 and a second edge 116 of the rear wall 102. The bottom wall 42 of the housing 30 surrounds the bottom surface of the chamber 32. Further, in the present embodiment, the top wall 54 of the housing 30 extends primarily along the x-axis 12 and curves downward to extend along the z-axis 16 such that a curved elbow 120 of the housing 30 is formed within an upper rear portion 122 of the chamber 32.

Accordingly, a chamber height 124 is defined between the top wall 54 and the bottom wall 42 along the z-axis 16, and a chamber width 126 is defined between the side walls 106, 112 of the housing 30. In some embodiments, the top wall 54 and the rear wall 102 may be formed as a unitary structure, such as a single surface with an elbow disposed therein. As discussed in more detail herein, although housings without curved walls may also use the present techniques in some embodiments, a housing 30 with a curved elbow 120 may direct airflow within the chamber 32 more smoothly or with less turbulence than a similar housing in which no curve is formed. Further, in some embodiments, the top and rear walls 102 may be disposed at a right angle 128 relative to each other, and the curved elbow 120 of the housing 30 may be defined by a secondary spacer insert 130 disposed between the top wall 54 and the rear wall 102. In such embodiments, the accessory spacer insert 130 includes: a first side 132 disposed against the top wall 54; a second side 134 disposed against the rear wall 102; and a concave surface 136 extending between the sides 132, 134 and defining the curved elbow 120. In contrast to a housing shaped as a rectangular prism without the supplementary spacer insert 130 therein, embodiments with the supplementary spacer insert 130 advantageously restrict airflow from a portion of the interior volume 34 of the chamber 32.

Additionally, within the chamber 32 defined by the housing 30, the AM system 10 includes a spacer deflector 140 that directs one or more air flows in the chamber 32. The spacer deflector 140 may be any suitable solid or hollow structure formed from any suitable material (e.g., metal, ceramic, polymer). The illustrated embodiment of the spacer deflector 140 occupies or limits a portion of the interior volume 34 of the chamber 32, hereinafter referred to as the volume 142 occupied by the spacers of the chamber 32. In this way, the spacer deflector 140 separates the gas volume 144 of the chamber 32 through which one or more gas streams may move from the volume 142 occupied by the spacer. In embodiments having the accessory spacer insert 130, the portion of the interior volume 34 of the chamber 32 occupied by the accessory spacer insert 130 further contributes to the volume 142 occupied by the spacer. In the present embodiment, the spacer deflector 140 has a width 150, the width 150 extending along the entire chamber width 126 defined between the sidewalls 106, 112. In some embodiments, the width 150 of the spacer deflector 140 may alternatively extend along a portion of the chamber width 126 rather than the entire chamber width 126, such that the airflow may be selectively directed along the spacer deflector 140 along a plane defined between the z-axis 16 and the x-axis 12. In addition, the spacer deflector 140 has a height 152 that extends along a portion of the chamber height 124. That is, the bottom surface 154 of the spacer deflector 140 is separated from the bottom wall 42 by a lower separation distance 156 extending along the z-axis 16, and the top surface 160 of the spacer deflector 140 is separated from the top wall 54 by an upper portion separation distance 162. The height 152 of the spacer deflector 140, the lower separation distance 156, and the upper separation distance 162 together are equal to the chamber height 124.

Further, for the illustrated embodiment, the spacer deflector 140 is tapered along the z-axis 16 such that a first length 164 of the spacer deflector 140 defined along the x-axis 12 (proximate the top surface 160 of the spacer deflector 140) is greater than a second length 166 of the spacer deflector 140 defined along the x-axis 12 (proximate the bottom surface 154 of the spacer deflector 140). As used herein, two elements are described as "adjacent" when they are at least disposed in close proximity or proximity to each other. In some embodiments, adjacent elements may be in direct contact. Thus, in the present embodiment, the front surface 170 of the spacer deflector 140 is angled to form an obtuse angle 172 between the front surface 170 and the bottom surface 154 and an acute angle 174 between the front surface 170 and the top surface 160. The front surface 170 is disposed opposite a rear surface 176 of the spacer deflector 140, with the rear surface 176 extending generally parallel to the z-axis 16 in this embodiment. As recognized herein, any surface of the spacer deflector 140 may be formed in any suitable shape or orientation such that the rear surface 176 may be angled with respect to the z-axis 16, the front surface 170 may be tapered in the opposite direction, and the like, in accordance with the present disclosure.

In certain embodiments, the spacer deflector 140 may be coupled to the sidewalls 106, 112 via an interference fit (interference fit), an adhesive, a fastener, or any other suitable attachment process or means for maintaining the position of the spacer deflector 140 within the chamber 32. However, it should be understood that the spacer deflector 140 may additionally or alternatively be supported within the chamber 32 by any suitable element or process, such as a base extending from the bottom wall 42 to support the bottom surface 154 of the spacer deflector, a hanger or support that suspends the top surface 160 of the spacer deflector 140 from the top wall 54, or the like. Further, in some embodiments, the spacer deflector 140 may instead be formed by a wall of the housing rather than by an insert, such that a "through-hole" shaped as a spacer deflector 140 and bounded by a surface of the housing 30 is formed between the side walls 106, 112. Fewer parts or simplified structural or assembly processes may be utilized in those embodiments in which the through-holes of AM system 10 may be fluidly coupled to ambient atmosphere 36 as compared to embodiments in which spacer flow director 140 is inserted into chamber 32.

To facilitate the description of the airflow within the chamber 32, the boundaries of the spacer deflector 140 will be used to delineate certain portions of the chamber 32. For example, as currently illustrated, a front surface plane 200 extending in the same plane as the front surface 170 of the spacer deflector 140 to coincide with the housing 30 is referred to herein as dividing an upstream portion 202 of the chamber 32 from a downstream portion 204 of the chamber 32. Thus, by defining and referring to the front surface plane 200, the spacer deflector 140 is disposed in the downstream portion 204 of the chamber 32. Further, for components of the AM system 10 other than the chamber 32, the terms "upstream" and "downstream" are used to refer to the relative placement of the components along the direction of airflow through the chamber 32. As used herein, directional terms, such as above, below, upper, lower, and the like, are intended to refer to the mounting location of the AM system 10 or the relative positions of components in a construction. For example, the terms "upper" and "lower" are intended to refer to the relative placement of components along the z-axis 16 when installed within the AM system 10.

The illustrated spacer deflector 140 is shaped to direct airflow within the chamber 32 along one or more desired flow paths defined along channels or conduits within the chamber 32. For example, as shown, a main exhaust passage 220 is defined between the bottom surface 154 of the spacer deflector 140 and the bottom wall 42 of the chamber. Additionally, the top surface 160 of the spacer deflector 140 extends along the x-axis 12, curves, and extends into the rear surface 176 of the spacer deflector 140. Thus, the curved top edge portion 222 of the spacer deflector 140 generally corresponds (e.g., has the same radius of curvature within 5%) to the curvature of the curved elbow 120 of the shell 30. As such, a bypass exhaust passage 224 is defined between the top surface 160 and the rear surface 176 of the spacer deflector 140 and the top wall 54 and the rear wall 102 of the housing 30. Although the spacer deflector 140 is shown in the present embodiment as having sharp edges formed between other surfaces of the spacer deflector 140, it should be appreciated that in other embodiments, any suitable number of edges of the spacer deflector 140 may be rounded or otherwise shaped to produce a desired aerodynamic and/or deflecting effect.

As discussed herein, the airflow along the passages 220, 224 may be selectively provided and controlled by adjusting components of the AM system 10. To provide one or more airflows to the chamber 32 (e.g., as the inlet airflow 80 in fig. 1), the AM system 10 includes an airflow system 240 coupled to the front wall 100 of the housing 30. For example, the illustrated airflow system 240 includes: an upper airflow system 242 disposed in an upper portion 244 of the chamber 32; and a lower airflow system 246 disposed in a lower portion 248 of the chamber 32 and vertically below the upper airflow system 242 along the z-axis 16. Upper airflow system 242 may be integrated with housing 30 and/or coupled to housing 30. The upper gas flow system 242 includes an upper gas inlet 250 for supplying an upper gas flow 252 to the chamber 32. For the illustrated embodiment, the upper gas inlet 250 includes a plurality of circular openings 254 defined in the front wall 100 of the housing 30. However, the circular openings 254 may have any suitable shape, size or number (e.g., including a single opening) to provide a substantially uniform or laminar flow of gas within the chamber 32. Further, upper gas inlet 250 may be coupled to an upper gas delivery device 256, which upper gas delivery device 256 is in turn coupled to a gas supply line. The upper gas delivery device 256 may help to uniformly supply the upper gas flow 252 through the chamber length 104 of the chamber 32.

The embodiment of AM system 10 shown in fig. 2 also includes a lower airflow system 246 disposed in a lower portion 248 of chamber 32. Lower airflow system 246 may be integrated with housing 30 and/or coupled to housing 30. In addition, the lower gas flow system 246 includes a lower gas inlet 260 for supplying a lower gas flow 262 to the chamber 32. For the illustrated embodiment, the lower gas inlet 260 is defined by a divider wall 264 (e.g., an upper divider wall 266 and a lower divider wall 268) that extends along the y-axis 14 from the first sidewall 106 to the second sidewall 112 of the housing 30 across the entire chamber width 126 of the chamber 32. The illustrated dividing wall 264 also extends along the x-axis 12 from the front wall 100 through at least a portion of the chamber length 104 of the chamber 32 toward the rear wall 102 of the housing 30. As used herein, the marking is between the upper portion 244 and the lower portion 248 of the chamber 32 based on the vertical position of the dividing wall 264 (e.g., along the z-axis 16). That is, the upper portion 244 of the chamber 32 generally refers to any portion of the chamber 32 disposed above the dividing wall 264, while the lower portion 248 of the chamber 32 refers to any portion of the chamber 32 disposed horizontally with the dividing wall 264 or below the dividing wall 264. As such, the upper portion 244 can include an upper 50%, an upper 60%, an upper 70%, or an upper 80% along the z-axis 16 of the chamber 32, while the lower portion 248 can include a corresponding lower 50%, a lower 40%, a lower 30%, or a lower 20% along the z-axis 16 of the chamber 32.

Lower gas inlet 260 is arranged such that lower gas flow 262 is directed between dividing walls 264 to flow towards build platform 40. The dividing wall 264 is arranged such that the lower gas flow 262 exits proximate to a lower gas outlet 270 of the build platform 40. The lower gas stream 262 then flows through the build platform 40. Lower gas flow 262 exiting lower gas inlet 260 flows generally uniformly in a direction parallel to x-axis 12, parallel to a top surface 274 of build platform 40, and/or perpendicular to z-axis 16. Further, the lower gas inlet 260 is arranged such that the presence of the dividing wall 264 does not interfere with the movement and operation of the powder application device 44 or other various components of the AM system 10. Lower gas inlet 260 may be coupled to lower gas delivery device 276, lower gas delivery device 276 in turn being coupled to a gas supply line. The lower gas delivery device 276 may help to uniformly supply the lower gas flow 262 through a majority of the entire chamber length 104.

For the illustrated embodiment, the AM system 10 further includes a flow conditioning device 280, the flow conditioning device 280 configured to facilitate conditioning the flow characteristics of the upper air flow 252 and the lower air flow 262. The flow characteristics of the upper and lower gas streams 252 and 262, respectively, are adjusted to desired levels by the flow conditioning device 280 to remove particles from the chamber 32. In some embodiments, the flow conditioning device 280 may be omitted.

As it travels through the chamber 32, at least a portion of the upper airflow 252 and/or the lower airflow 262 contacts the front surface 170 of the spacer deflector 140. In this embodiment, the front surface 170 of the spacer deflector 140 is angled to promote a portion of the upper airflow 252 and the lower airflow 262 to flow down the z-axis 16 and into the main exhaust passage 220. In this embodiment, the upper airflow 252 and the lower airflow 262 may collectively form the inlet airflow 80 discussed above with reference to fig. 1. The main exhaust passage 220 fluidly couples the upstream portion 202 of the lower portion 248 of the chamber 32 to the gas outlet 290 of the AM system 10. Further, at least a portion of the upper airflow 252 is directed from the upstream portion 202 of the chamber 32 proximate the top wall 54 and into the bypass exhaust passage 224. The bypass exhaust passage 224 then directs or introduces a portion of the upper airflow 252 therein into the main exhaust passage 220 downstream of the main exhaust passage inlet 292 and upstream of the gas outlet 290 of the main exhaust passage 220. In this manner, the gas outlet 290 discharges the exhaust gas flow 82 from the downstream portion 204 of the chamber 32. The exhaust stream 82 includes the upper stream 252, the lower stream 262, and a majority of any particulates generated during AM processing.

In the illustrated embodiment, the gas outlet 290 is defined in the rear wall 102 of the housing 30 opposite the front wall 100, and the upper and lower gas flows 252, 262 enter the chamber 32 through the front wall 100. A gas outlet 290 may be defined in the rear wall 102 adjacent the lower portion 248 of the chamber 32 such that at least a portion of the lower gas flow 262 travels directly tangentially over the build platform 40, through the main exhaust passage 220 and through the gas outlet 290. Although the gas outlets 290 are shown as generally rectangular slots extending along the chamber width 126 for simplicity, the gas outlets 290 may be any suitable shape (e.g., circular, polygonal, oval) extending along any suitable portion of the chamber width 126 to enable adequate discharge of the exhaust gas stream 82. In some embodiments, the gas outlet 290 may include a plurality of openings in the rear wall 102 to discharge the exhaust gas flow 82.

The gas outlet 290 may be coupled to a gas moving device to draw and discharge the exhaust gas flow 82 from the chamber 32. In some embodiments, the gas moving device may be a fan or blower. Additionally, in some embodiments, the gas-moving device may also include a filtration system configured to filter the exhaust gas flow 82, for example, by removing any particulates suspended within the exhaust gas flow 82 that have been removed from the chamber 32. After filtration, exhaust gas stream 82 may be directed to upper gas delivery device 256 and/or lower gas delivery device 276 for reuse in upper gas flow system 242 and lower gas flow system 246. The upper gas flow 252 and the lower gas flow 262 may include an inert gas (e.g., argon or nitrogen), but may additionally include any other suitable gas configured to facilitate removal of generated particles from the chamber 32 during operation of the AM system 10.

It should be noted that because the AM system 10 employs the spacer deflector 140, the interior volume 34 of the chamber 32 for receiving the airflow therein is effectively divided into a volume 142 occupied by the spacer deflector 140 (and in some embodiments, including the volume occupied by the supplemental spacer insert 130), and a gas volume 144 for directing the upper airflow 252 and the lower airflow 262. Accordingly, the gas volume 144 is reduced relative to the internal volume 34 of the chamber 32, thereby enabling a reduction in flow rate and corresponding operating costs of the AM system 10 to remove particles from the chamber 32. Further, in certain embodiments, a relatively smaller or less powerful pump or blower may be used to deliver the upper airflow 252 and/or the lower airflow 262 relative to a pump or blower used to deliver airflow to a chamber that lacks the spacer flow director 140 and/or the sub-spacer insert 130 and therefore has a larger gas volume.

As described above, the spacer deflector 140 may help to substantially reduce or eliminate recirculation or turbulence within the chamber 32 and, thus, improve the performance and efficiency of the AM system 10 such that particles generated during AM processing can be effectively removed with reduced airflow. Fig. 3 is a schematic cross-sectional view illustrating an embodiment of a chamber 32 having a spacer deflector 140 disposed therein. In this embodiment, the AM system 10 includes a tool area or powder application sub-chamber 318, with a powder application device 44 (e.g., a recoater blade) disposed in the powder application sub-chamber 318. In addition, the spacer deflector 140 is positioned within the chamber 32 to block or fluidly separate the volume 142 occupied by the spacer confined by the spacer deflector 140 from the gas volume 144 of the chamber 32, with the upper gas 252 and the lower gas 262 being directed through the gas volume 144. As shown, the volume 142 occupied by the spacer is confined within a plane formed between the z-axis 16 and the x-axis 12 by the top surface 160, the bottom surface 154, the front surface 170, and the rear surface 176, the front surface 170 extending between the top surface 154 and the bottom surface 160 along the upstream portion 320 of the spacer deflector 140, the rear surface 176 extending between the top surface 154 and the bottom surface 160 along the downstream portion 322 of the spacer deflector 140.

In the illustrated embodiment, the top upstream edge 340 or leading edge of the spacer deflector 140 extends further from the rear wall 102 of the housing 30 than the bottom upstream edge 342 of the spacer deflector 140 such that the front surface 170 is disposed at a guide angle 344 of about 20 ° with respect to the z-axis 16 in this embodiment. The guide angle 344 of the spacer deflector 140 may generally be formed or selected to correspond to (e.g., within 10%) the beam angle 62 of the focused energy beam 52, substantially the same as the beam angle 62 of the focused energy beam 52, or substantially parallel to the beam angle 62 of the focused energy beam 52, with the energy generation system 50 directing the focused energy beam 52 through the laser window 56 and into the build platform 40. As described herein, in various embodiments, a lead angle 344 that is "substantially" parallel or the same as toe angle 62 refers to a lead angle 344 that is within ± 10%, ± 5%, or ± 1% of toe angle 62. Additionally, the guide angle 344 may be any suitable angle, such as an angle between about 10 degrees and about 60 degrees. As otherwise noted herein, in various embodiments, an angle of "about" a value refers to an angle within ± 10%, ± 5%, or ± 1% of the value. Due to the guide angle 344 of the front surface 170, the spacer deflector 140 may be formed to have an increased or maximized length that extends closer to the build platform 40 and separates a larger portion of the interior volume 34 of the chamber 32 into the spacer occupied volume 142 than embodiments of the spacer deflector 140 having a substantially vertical front surface.

Further, in the present embodiment, the gas flow within the chamber 32 (including the upper gas flow 252 and the lower gas flow 262) is illustrated by various fill patterns, each representing a respective flow rate or range of flow rates. For gas flows represented by a fill pattern having lines, the lines generally have an orientation that indicates a flow direction of the gas flow within various portions of chamber 32. For example, the upper gas flow 252 provided into the chamber 32 through the upper gas inlet 250 generally traverses the chamber 32 in a relatively straight direction (e.g., parallel to the x-axis 12) and then splits into a first portion of the upper gas flow 252 directed downward to the build platform 40 and a second portion of the upper gas flow 252 directed upward to the bypass exhaust passage 224. The upper gas flow 252 may generally be divided into a first portion and a second portion along an open length 350 of the chamber 32, the open length 350 of the chamber 32 being defined between the upper gas inlet 250 and a separation point 352 on the front surface 170 of the spacer deflector 140. The separation point 352 may be the point or location at which the spacer deflector 140 redirects or separates the upper airflow 252 and, thus, may move up or down along the front surface 170 based on the current operation of the AM system 10.

Upon contacting the front surface 170 of the spacer deflector 140, any remaining portion of the horizontally traveling upper airflow 252 is directed into the main exhaust passage 220 or the bypass exhaust passage 224, respectively, defined between the spacer deflector 140 and the housing 30. In particular, the bypass exhaust passage 224 provides an outlet from the upstream portion 202 of the chamber 32 through which a portion of the upper airflow 252 (also referred to herein as the bypass exhaust flow 354) within the bypass exhaust passage 224 may experience laminar flow. Indeed, the present AM system 10 may utilize generally lower flow rates and/or volumes to continuously remove particles from the chamber 32 from the upper and lower airflows 252, 262 without substantial recirculation, as compared to an arrangement having similarly shaped and/or volume chambers without a bypass exhaust passage. Indeed, for the illustrated embodiment in which gas flow system 240 includes upper gas flow system 242 and lower gas flow system 246, the ratio of the flow rate of upper gas flow 252 to the flow rate of lower gas flow 262 into chamber 32 may be about 3: 1 and about 1: 1, or about 2: 1. In contrast, other AM systems lacking a spacer deflector 140 may use more than 6: 1 flow rate ratio of upper to lower gas flow. As noted herein, in various embodiments, a flow rate ratio of "about" value refers to a flow rate ratio that is within + -10%, + -5%, or + -1% of the value.

Further, the lower gas flow 262 provided into the chamber 32 through the lower gas inlet 260 generally flows at a downward angle and then generally parallel to the build platform 40 before traveling over the build platform 40 and entering the exhaust channel inlet 292 of the main exhaust channel 220. The portion of upper gas flow 252 and the portion of lower gas flow 262 entering main exhaust passage inlet 292 are hereinafter referred to as main exhaust gas flow 356. The bypass exhaust passage 224 is fluidly coupled to the main exhaust passage 220 at a separation distance 360 downstream of the main exhaust passage inlet 292. In this manner, bypass exhaust flow 354 passing through bypass exhaust passage 224 is introduced into main exhaust flow 356 within main exhaust passage 220. In the present embodiment, the connection point 362 or injection point between the two passages 220, 224 is oriented to align with the direction of flow of the main exhaust gas flow 356 within the main exhaust passage 220 (e.g., along the x-axis 12) such that the bypass exhaust passage 224 includes a bend 364 to redirect the bypass exhaust gas flow 354 therein from flowing along the z-axis 16 to flowing along the x-axis 12. As such, the exhaust flow 82 (e.g., including the bypass exhaust flow 354 and the main exhaust flow 356) from the two channels 220, 224 and exiting the gas outlet 290 downstream of the junction 362 is generally laminar. The connection point 362 may generally be defined between the housing 30 and the spacer deflector 140 by a downstream protrusion 370 of the spacer deflector 140, the downstream protrusion 370 tapering into a sharp trailing edge 372. In other embodiments, the connection point 362 may have another suitable shape or configuration (e.g., an ejector) such that the respective flow rates of the gas streams 354, 356 along the channels 220, 224 are sufficient to maintain or reduce the turbulence of the gas streams 354, 356 below a threshold level, such as a level below which the streams transition from laminar to turbulent flow (e.g., as defined by a critical reynolds number).

In addition, the AM system 10 includes a control system 374, which control system 374 controls the flow rates of the upper and lower gas streams 252, 262 to reduce or eliminate recirculation and/or particle build-up within the chamber. For example, an upper actuator 376 of the upper gas delivery device 256 and a lower actuator 378 of the lower gas delivery device 276 are operably coupled to the controller 20 (e.g., which are components of the control system 374 of the AM system 10). Actuators 376, 378 may be any suitable controllable device that regulates the upper and lower gas flows 252, 262 from upper and lower gas delivery devices 256, 276, such as one or more fluid valves and/or one or more pumps or blowers. By adjusting the actuators 376, 378, the controller 20 and/or control system 374 can thus control the upper airflow 252 and the lower airflow 262 in addition to the rest of the AM system 10 discussed above. The controller 20 may be configured to control one or more fluid flow characteristics of the upper gas flow 252 and the lower gas flow 262 to substantially reduce or eliminate gas entrainment or turbulent gas flow within the chamber 32 such that particles may be effectively removed from the chamber 32 (e.g., discharged from the chamber 32 via the gas outlet 290). The flow characteristics may include flow distribution, flow rate (e.g., mass flow rate, volume flow rate), flow velocity, flow direction or angle, flow temperature, or any combination thereof.

Additionally, control system 374 of AM system 10 includes one or more sensors to measure operating parameters within chamber 32 to control upper airflow system 242 and lower airflow system 246 based on these operating parameters. For example, as shown, a sensor 380 or sensor assembly is fluidly coupled to bypass exhaust passage 224 to monitor a parameter indicative of a flow rate and/or particulate concentration of bypass exhaust flow 354 therein. That is, because the bypass exhaust passage 224 includes a smaller cross-section and/or volume than the main exhaust passage 220 or the upstream portion 202 of the chamber 32, fewer sensors or less sensitive sensors may be used for the smaller volume to effectively monitor the bypass exhaust flow 354 within the bypass exhaust passage 224 as compared to sensors suitable for other portions of the chamber 32. However, in some embodiments, the AM system 10 includes multiple sensors disposed at various locations (e.g., within the gas outlet 290, downstream of the gas outlet 290, upstream of the spacer flow director 140, etc.).

Sensor 380 may be any suitable sensor for monitoring an operating parameter of bypass exhaust flow 354, including a concentration sensor, a pressure sensor, a flow rate sensor, a particulate or smoke sensor, and the like. Additionally, as used herein, the term "sensor" may include any suitable instrument capable of obtaining feedback through direct or indirect observation, including an exchanger or transducer. Sensor 380 is communicatively coupled to controller 20 that receives and analyzes signals from sensor 380, thereby enabling controller 20 to determine and monitor bypass exhaust flow 354 within bypass exhaust passageway 224.

For example, during operation of the AM system 10, the controller 20 receives feedback from the sensor 380 indicative of an operating parameter of the bypass exhaust flow 354, such as flow rate or particulate concentration. Based on the feedback indicative of the operating parameter, the controller 20 may determine whether the operating parameter exceeds or is outside of a predefined operating parameter threshold set for the operating parameter (e.g., a threshold previously stored in the memory circuit 22). In response to determining that the operating parameters are within their respective operating thresholds, the controller 20 may continue to operate the AM system 10 according to its current set point. However, in response to determining that the operating parameter is outside (e.g., above or below) its respective operating parameter threshold, the controller 20 may perform a control action to adjust the operating parameter. For example, controller 20 may instruct gas flow system 240 to adjust the flow rate of one or both of gas flows 252, 262 provided to the build chamber to adjust the current value of the operating parameter to within a predefined operating threshold. In addition, the controller 20 may provide an alert to a user interface or server indicating an operating parameter, such as an alert indicating a recommendation to maintain the AM system 10.

For example, the controller 20 may monitor the flow rate of the bypass exhaust flow 354 within the bypass exhaust passage 224 to ensure that the flow rate is within a tolerance or range of a target flow rate (hereinafter referred to as a flow rate threshold). Indeed, as recognized herein, flow rates below a flow rate threshold may indicate stagnation of the bypass exhaust flow 354 within the bypass exhaust passage 224 and/or stagnation of the upper and lower airflows 252, 262 within the upstream portion 202 of the chamber 32, which may result in particulate accumulation or build-up. Additionally, a flow rate above the flow rate threshold may indicate an oversupply of upper airflow 252 and lower airflow 262 to chamber 32, as a lower, more cost-effective flow rate may be sufficient to properly operate AM system 10. In some cases, flow rates above the flow rate threshold may also indicate turbulence (e.g., flow at high reynolds numbers) in which inertial forces of the bypass exhaust flow 354 exceed viscous forces, thereby creating flow instabilities that may cause recirculation of particulates within the chamber 32. Thus, if controller 20 determines, based on feedback from sensor 380, that the flow rate of bypass exhaust flow 354 within bypass exhaust passage 224 is below the flow rate threshold, controller 20 instructs air flow system 240 to provide an increased flow rate of one or both of upper air flow 252 and lower air flow 262 into chamber 32. Additionally, if the controller 20 determines that the flow rate of the bypass exhaust flow 354 within the bypass exhaust passageway 224 is above the flow rate threshold, the controller 20 instructs the air flow system 240 to provide a reduced flow rate of one or both of the upper and lower air flows 252, 262 into the chamber 32, thereby retaining a portion of the upper and lower air flows 252, 262 and/or reducing turbulence therein.

The controller 20 may additionally or alternatively directly monitor the particulate concentration of the bypass exhaust flow 354 within the bypass exhaust passage 224 to ensure that the particulate concentration is within a tolerance or range of a target particulate concentration (hereinafter referred to as a particulate concentration threshold). Controller 20 may generally control gas flow system 240 to ensure that the concentration of particles within chamber 32 remains below a particle concentration threshold to reduce or prevent particle accumulation or build-up within chamber 32. Additionally, the lower limit of the particle concentration threshold may be set to a value that can be effectively processed by the cost-effective flow rates of the upper and lower gas flows 252, 262. Thus, if the controller 20 determines that the particle concentration is above the particle concentration threshold, the controller instructs the airflow system 240 to provide an increased flow rate of one or both of the upper airflow 252 and the lower airflow 262 into the chamber 32. Alternatively, if the controller 20 determines that the particle concentration is above the particle concentration threshold, the controller 20 instructs the airflow system 240 to conserve the upper airflow 252 and the lower airflow 262 by providing a reduced flow rate of one or both of the upper airflow 252 and the lower airflow 262 into the chamber 32.

As such, in certain embodiments, the controller 20 operates the AM system 10 to maintain the flow rate of the bypass exhaust gas flow 354 and/or the particulate concentration of the bypass exhaust gas flow 354 within their respective operating parameter thresholds. In some embodiments, the controller 20 may place more weight on the particulate concentration of the bypass exhaust flow 354 such that, even with flow rates above the flow rate threshold, the controller 20 may adjust the AM system 10 to maintain the particulate concentration within the particulate concentration threshold. In some embodiments, the controller 20 may additionally or alternatively monitor the rate of change of the operating parameter, compare the rate of change to a corresponding threshold rate of change, such that control actions may be taken based on the rate of change of the operating parameter. Additionally, although discussed above with reference to sensors 380 capable of monitoring the flow rate and particulate concentration of the bypass exhaust flow 354, it should be understood that in certain embodiments, two separate sensors, one for monitoring each operating parameter, may instead be employed within the AM system 10.

The spacer deflector 140 may be shaped or adjusted to fit any embodiment of the AM system 10. For example, fig. 4 is a partially schematic cross-sectional view illustrating an embodiment of a chamber 32 having a spacer deflector 140 disposed therein. As shown, the spacer deflector 140 of fig. 4 is formed with a front surface 170 having a 45 ° guide angle 344 relative to the z-axis 16. As such, the volume 142 occupied by the spacer defined by the illustrated spacer deflector 140 is smaller than the volume 142 occupied by the spacer of fig. 3. The spacer deflector 140 may generally have a D-shaped cross-section with a bypass exhaust passage 224 and a main exhaust passage 220 formed therearound, respectively. Due to the steep incline of the front surface 170 of the spacer deflector 140, the portion of the upper airflow 252 directed to the main exhaust passage 220 to form the main exhaust flow 356 may be greater than the portion of the upper airflow 252 directed to the main exhaust passage 220 of fig. 3. Indeed, as shown, the separation point 352 on the front surface 170 of the spacer deflector 140 is closer to the top wall 54 of the housing 30 than the separation point 352 of fig. 3.

Additionally, the present energy generation system 50 may provide a focused energy beam 52 to the build platform 40 at a beam angle 62 of 45 ° such that the spacer deflector 140 is disposed proximate to the build platform 40 without interfering with the build process. The spacer deflector 140 also includes a sharp trailing edge 372 for smoothly introducing the bypass exhaust flow 354 from the bypass exhaust passage 224 into the main exhaust flow 356 within the main exhaust passage 220. The bypass exhaust flow 354 enters the main exhaust passage 220 downstream of the main exhaust passage inlet 292 and combines with the main exhaust flow 356 to form the exhaust flow 82. Thus, the particular dimensions of the spacer flow director 140 may be tailored to the physical layout of various AM systems, thereby excluding the volume 142 occupied by the spacer from the gas volume 144 within the chamber 32. The chamber 32 with the gas volume 144 utilizes the reduced gas flow rates of the upper gas flow 252 and the lower gas flow 262 to remove particles as compared to a chamber without the spacer deflector 140.

The spacer deflector 140 may include additional physical features to facilitate movement of the air streams 354, 356 through the bypass exhaust passage 224 and the main exhaust passage 220, as described below with reference to fig. 5-7. Fig. 5 is a partial schematic cross-sectional view illustrating an embodiment of AM system 10 in which spacer deflector 140 forms a tapered neck 410 directly downstream of bypass exhaust channel inlet 412 of bypass exhaust channel 224. The top surface 160 of the spacer deflector 140 is sloped or angled along the x-axis 12 such that a first height 420 of an upstream portion 422 of the bypass exhaust passage 224 is greater than a second height 424 of a downstream portion 426 of the bypass exhaust passage 224. In this way, the bypass exhaust passage inlet 412 provides a larger area through which the bypass exhaust gas flow 354 may be directed or leaked into the bypass exhaust passage 224, thereby reducing recirculation and/or airflow rates within the chamber 32.

Fig. 6 is a partial schematic cross-sectional view illustrating an embodiment of the AM system 10 in which the laser window 56 protrudes into the top wall 54 of the housing 30 (e.g., is recessed into the top wall 54, extending vertically downward from the top wall 54). Thus, the energy generation system 50 may be positioned closer to the build platform 40 than an energy generation system positioned away from the build platform 40 to limit potential scattering of the focused energy beam 52. In addition, the laser window 56 protrudes into the chamber 32 and directs a portion of the upper airflow 252 within the chamber 32 into the bypass exhaust channel 224 to form a bypass exhaust flow 354. That is, a portion of the upper airflow 252 may impinge on the laser window 56, change flow direction, and enter the bypass exhaust channel 224. In some embodiments, the laser window 56 may be fitted or formed with a beveled edge 440 to provide a smooth transition for air flow from a surface 442 of the laser window 56 to an inner surface 444 of the top wall 54. In some embodiments, the laser window 56, positioned partially or entirely within the chamber 32, may change the flow direction of the upper airflow 252 to vertical (rather than horizontal) upon entering the bypass exhaust channel 224. In some embodiments, the laser window 56 may extend the effective length of the bypass exhaust channel 224 by increasing the vertical distance between the bypass exhaust channel 224 and the upstream portion 202 of the chamber 32, thereby improving the funneling effect for directing the bypass exhaust flow 354 into the bypass exhaust channel 224.

Fig. 7 is a partial schematic cross-sectional view illustrating an embodiment of an AM system 10 having a first interconnecting channel 460 and a second interconnecting channel 462 formed by a spacer flow director 140. Interconnecting passages 460, 462 (e.g., interconnecting exhaust passages) extend through the spacer deflector 140 along the x-axis 12 to fluidly couple respective portions of the upstream portion 202 of the chamber 32 to the bypass exhaust passage 224. For example, the first interconnecting passage 460 has a first interconnecting passage inlet 470 disposed vertically below the bypass exhaust passage inlet 412 and a first interconnecting passage outlet 472 fluidly coupled to the bypass exhaust passage 224 downstream of the bypass exhaust passage inlet 412. The illustrated second interconnecting passage 462 includes a second interconnecting passage inlet 474 disposed vertically below the bypass exhaust passage inlet 412 and the first interconnecting passage inlet 470. Additionally, second interconnecting passage 462 has a second interconnecting passage outlet 476 that is fluidly coupled downstream of first interconnecting passage outlet 472 upstream of the connection point 362 between bypass exhaust passage 224 and main exhaust passage 220.

In this manner, a portion of the upper and lower gas flows 252, 262 within the chamber 32 may be directed into any of the inlets 412, 470, 474 and combined into a bypass exhaust gas flow 354 within the downstream portion 480 of the bypass exhaust passage 224 and directed out of the chamber 32. Thus, the interconnecting passages 460, 462 may facilitate reducing or eliminating recirculation within the chamber 32 by providing additional flow paths between the spacer deflector 140 and the gas outlet 290. It should be appreciated that in some embodiments, the interconnecting channels 460, 462 may span the entire width of the spacer deflector 140 defined along the y-axis 14 such that the spacer deflector 140 may be a collection of three separate spacer deflector portions 482, 484, 486. Alternatively, the interconnecting channels 460, 462 may span only a portion of the width 150 of the spacer deflector 140. In such embodiments, the plurality of interconnected channels may be arranged along the y-axis 14 (e.g., disposed alongside one another in the current view of the plane between the x-axis 12 and the z-axis 16) such that the upper airflow 252 and the lower airflow 262 within the chamber 32 encounter the array of openings at the front surface 170 of the spacer deflector 140. Additionally, although two interconnecting channels 460, 462 are shown in the vertical middle portion 490 of the spacer deflector 140, it should be understood that any suitable number of interconnecting channels 460, 462 may be included along any suitable vertical extent of the spacer deflector 140.

In view of the foregoing, FIG. 8 is a flow diagram of an embodiment of a process 550 by which AM system 10 may be operated during fabrication of an article by process 550. The following discussion makes reference to the numbering of elements used throughout fig. 1-7. It should be understood that the steps discussed herein are merely exemplary, and in other embodiments, certain steps may be omitted, repeated, performed simultaneously, and/or performed in a different order than the order discussed herein. It should be noted that one or more steps of process 550 may be stored in memory circuit 22 and executed by processing circuit 24 of controller 20. For the embodiment shown in fig. 5, process 550 begins by depositing (step 552) a quantity of powdered material onto build platform 40 within chamber 32 of AM system 10. For example, controller 20 instructs powder application device 44 to deposit powder material onto build platform 40. Controller 20 instructs positioning system 70 to move powder application device 44 and/or build platform 40 to any suitable position relative to each other along x-axis 12, y-axis 14, and z-axis 16, or a combination thereof, to deposit the powder material in a layer-by-layer manner during each deposition cycle of powder application device 44.

The illustrated embodiment of the process 550 continues by supplying (step 554) one or more gas flows (e.g., the upper gas flow 252 and the lower gas flow 262) into the chamber 32. For example, the controller 20 instructs the gas flow system 240 to supply the upper gas flow 252 and the lower gas flow 262 into the chamber 32 with any suitable flow characteristics (e.g., flow profile, flow rate (e.g., mass flow rate, volume flow rate), flow temperature, or any combination thereof, as discussed above). Process 550 includes directing a first portion of the one or more gas streams as primary exhaust gas stream 356 along primary exhaust passage 220 (step 556) and to gas outlet 290. For example, as described above, the main exhaust passage 220 is defined between the bottom surface 154 of the spacer deflector and the housing 30. Accordingly, main exhaust passage 220 extends between build platform 40 and gas outlet 290 to receive and direct main exhaust flow 356 from chamber 32.

The process 550 includes directing a second portion of the one or more gas flows as a bypass exhaust gas flow 354 along a bypass exhaust passage 224, the bypass exhaust passage 224 fluidly coupling the upstream portion 202 of the chamber 32 to the main exhaust passage 220. As described above, the bypass exhaust passage 224 is defined between the top and rear walls 54, 102 of the housing 30 and the top and rear surfaces 160, 176 of the spacer deflector 140. The bypass exhaust passage 224 directs the bypass exhaust flow 354 into the main exhaust passage 220. Thus, as described above, the spacer deflector 140 desirably separates the space 142 occupied by the spacer from the gas volume 144 of the chamber 32, reducing the utilized flow rate of the one or more gas streams for removing particles from the chamber 32 as compared to an AM system without the spacer deflector 140.

Further, as described above, the AM system 10 may adjust its operation based on operating parameters monitored by the sensor 380 fluidly coupled to the bypass exhaust passage 224. Accordingly, the illustrated process 550 includes receiving (step 560) feedback indicative of an operating parameter of the bypass exhaust flow 354 within the bypass exhaust passage 224. As discussed above with reference to fig. 3, the operating parameter may be any suitable parameter indicative of the flow rate and/or particulate concentration of the bypass exhaust flow 354. Further, process 550 includes determining (step 562) whether the operating parameter is outside of the corresponding operating parameter threshold. The operating parameter threshold may be a flow rate threshold, a particulate concentration threshold, or any other suitable threshold that may be compared to an operating parameter of the bypass exhaust flow 354.

In response to determining that the operating parameter is outside of the operating parameter threshold, the process 550 includes adjusting (step 564) the flow rate of the one or more gas flows supplied into the chamber 32. For example, controller 20 may instruct gas flow system 240 to adjust the flow rates of upper gas flow 252 and lower gas flow 262 provided to chamber 32 to adjust the current value of the operating parameter to be within, or close to, the operating parameter threshold. The process 550 then returns to step 562 to continue to determine whether the operating parameter is outside of the operating parameter threshold, as indicated by arrow 565.

In response to determining that the operating parameter is not outside of the operating parameter threshold, process 550 includes selectively applying (step 566) a focused energy beam to the powder material deposited on build platform 40. For example, the controller 20 instructs the energy generation system 50 to apply a focused energy beam 52 (e.g., a laser beam) onto portions of the powder bed 46. As described above, the focused energy beam 52 selectively melts and/or sinters the powder material of the powder bed 46 in a predefined manner to form a solidified layer while supplying the upper gas flow 252 and/or the lower gas flow 262.

In general, embodiments of the present disclosure include providing the gas streams 252, 262 in step 554 while applying the focused energy beam 52 in step 566 to enable efficient removal of particles generated in the build process. In some embodiments, supplying the gas streams 252, 262 in step 554, directing the main exhaust gas stream 356 in step 556, and directing the bypass exhaust gas stream 354 in step 558 may be performed simultaneously. In some embodiments, the application of the focused energy beam 52 in step 566 may be performed simultaneously with the supply of the gas streams 252, 262 in step 554, the directing of the main exhaust gas stream 356 in step 556, and the directing of the bypass exhaust gas stream 354 in step 558. Further, in some embodiments, adjusting the flow rate of the air flow 252, 262 in step 564 may be performed simultaneously with applying the focused energy beam 52 in step 566 to actively adjust the operation of the AM system 10 in real-time based on feedback from the sensor 380. Additionally, the present embodiment may generally alternate the application of the powder material in step 552 and the provision of the gas flows 252, 262 in step 554 such that the operation of the powder application device 44 is not disturbed by the gas flows 252, 262 within the chamber 32. In some embodiments, the process 550 may return to the step 552 to continue the process 550 to form additional solidified layers on the previously formed solidified layers, as indicated by arrow 567.

Technical effects of the present disclosure include improving the operating cost, performance, and efficiency of AM systems by effectively removing particles (such as smoke and/or particulate matter) generated during AM processing. The disclosed AM system utilizes a spacer flow director disposed within a downstream portion of the chamber to divide the volume of the chamber into smaller gas volumes from which particles can be removed using a reduced gas flow rate or gas flow. Further, in combination with the housing of the AM system, the spacer deflector defines a main exhaust channel that fluidly couples the lower portion of the chamber to the gas outlet. In addition, a bypass exhaust passage fluidly couples an upper portion of the chamber to a downstream portion of the main exhaust passage. In this way, the airflow through the chamber is selectively divided to flow around the spacer flow director to form a laminar flow path that may substantially reduce or eliminate gas entrainment and recirculation of particles inside the chamber.

This written description uses examples to disclose the technology, 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 incorporated methods. 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 have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.