Powder removal of 3D printing structure

Abstract

The present aspect includes a system for dusting a three-dimensional (3D) printed structure. The structure includes a first component holder configured to removably hold the 3D printed structure in an initial orientation relative to at least one opening to a hollow portion within the 3D printed structure; a fluid system configured to control a fluid to at least apply the fluid to or remove the fluid from the hollow portion to remove the powder from the hollow portion; and a movement system configured to move at least the 3D printed structure or the fluidic system according to a movement procedure based on the configuration of the hollow portion.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of priority of U.S. Provisional Application No. 63 / 421,454, filed on November 1, 2022, entitled "DEPOWDERING OF 3D - PRINTED STRUCTURES", and U.S. Non - Provisional Application No. 18 / 499,072, filed on October 31, 2023, entitled "DEPOWDERING OF 3D - PRINTED STRUCTURES", both of which have been assigned to the assignee of this application and are hereby incorporated by reference in their entirety as if fully set forth herein. Technical Field

[0003] The present disclosure generally relates to the depowdering of complex additive manufacturing (AM) structures and components, and more particularly to maximizing material recovery rates for efficient scaled - up AM operations. Background Art

[0004] The depowdering of complex - printed AM components is a critical post - processing task. Reactive metal powders are an inherently hazardous material that can also interfere with subsequent processes such as coating, and it is also an important economic consideration since for powder bed fusion processes, the price of raw materials typically ranges from tens to hundreds of USD / kg (US dollars per kilogram). Therefore, maximizing material recovery rates is a priority for efficient scaled - up AM operations, and there is a need for efficient methods for material recovery in AM operations.

[0005] Fine metal powders readily absorb moisture from the air, and once the relative humidity exceeds a few percent, the powders start to stick or adhere to surfaces. Both high - frequency and low - frequency vibrations can help initiate the flow of trapped materials. The use of compressed gas can be another technique for moving materials. For some applications and manufacturing processes, the active flow of liquids is used to clean the internal channels of flow bodies such as valves, heat exchangers, 3D - printed elements, etc.

[0006] Furthermore, it is generally not possible to directly visualize the areas within complex parts where powder may be trapped. For various reasons, these designs may also have multiple areas for material outflow, which may themselves have complex shapes, may be difficult to seal, and this ultimately limits the general applicability and usefulness of suction-based removal. The limitation of powder removal for multiple components on a build plate exacerbates this material recovery challenge. While facilitating workpiece holding purposes, the internal geometries of multiple components have different exit points and optimal orientations. Specialized software can be used to identify internal features and initiate a cycle to effectively remove material from tortuous channels; consider even a simple shape like a typical U-shaped bend geometry, where the material will only flow back and forth and will not completely leave the tube even after multiple cycles. For more complex topologically optimized internal structures, ensuring the necessary cleanliness targets may be an order of magnitude more difficult to achieve repeatedly. For certain designs in certain industrial sectors, it may not be achievable in an economically reasonable manner.

[0007] Accordingly, there is a need for an efficient powder removal mechanism that can withstand all of the above characteristics and challenges. SUMMARY OF THE INVENTION

[0008] A brief summary of one or more aspects is presented below in order to provide a basic understanding of these aspects. This summary is not an extensive review of all contemplated aspects and is neither intended to identify key or critical elements of all aspects nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0009] According to one example, a system for powder removal from a three-dimensional (3D) printed structure includes: a component holder configured to removably hold the 3D printed structure in an initial orientation relative to at least one opening leading to a hollow portion within the 3D printed structure; a fluid system configured to control fluid to at least apply fluid to or remove fluid from the hollow portion to remove powder from the hollow portion; and a movement system configured to move at least the 3D printed structure or the fluid system according to a movement program based on the configuration of the hollow portion.

[0010] Another example aspect includes a system for powder removal, wherein the fluid system includes an internal fluid channel within a portion of the component holder, and wherein the internal fluid channel is in fluid communication with a first opening leading to the hollow portion when the 3D printed structure is secured to the component holder, such that fluid flows through the portion of the component holder and the first opening to at least apply fluid to or remove fluid from the hollow portion.

[0011] Another example aspect includes a system for powder removal, further including a second component holder configured to removably hold a second 3D printed structure in a second initial orientation relative to at least one opening leading to a hollow portion within the second 3D printed structure, wherein the fluid system is further configured to at least apply fluid to or remove fluid from the hollow portion of the second 3D printed structure, and the movement system is further configured to move at least the second 3D printed structure or the fluid system according to a movement program based on the configuration of the hollow portion of the second 3D printed structure.

[0012] Another example aspect includes a system for powder removal, wherein the fluid system includes a first internal fluid channel within a portion of the first component holder and a second internal fluid channel within a portion of the second component holder, and wherein the first internal fluid channel and the second internal fluid channel are connected to each other.

[0013] Another example aspect includes a system for powder removal, further including a rigid structure connecting the component holder and the second component holder, wherein the movement system is configured to move the rigid structure such that the component holder and the second component holder move simultaneously.

[0014] Another example aspect includes a system for powder removal, wherein the movement program of the movement system includes vibration and rotation, and the vibration and rotation are configured to be applied to the 3D printed structure in a combined form based on the configuration of the hollow portion.

[0015] Another example aspect includes a system for powder removal, further including a sensor system configured to sense at least the amount of powder or fluid located within the hollow portion and at least adjust the control of the fluid system over the fluid and the control of the movement system over the movement based on the sensed amount.

[0016] Another example aspect includes a system for powder removal, wherein the component holder is configured to be fixed to a 3-D printing build plate.

[0017] Another example aspect includes a system for powder removal, further including an external fluid source including one or more nozzles configured to apply fluid to the hollow portion of the 3D printed structure at least at a second opening leading to the hollow portion within the 3D printed structure.

[0018] Another example aspect includes a system for powder removal, wherein the external fluid source is movable around the 3D printed structure to apply fluid to the hollow portion of the 3D printed structure at a plurality of different openings leading to the hollow portion within the 3D printed structure.

[0019] Another example aspect includes a system for powder removal, wherein a plurality of nozzles can be configured to apply a fluid to hollow portions of a plurality of different 3D printed structures located on a plurality of different component holders.

[0020] Another example aspect includes a system for powder removal, further including an outer housing member configured to house and enclose at least a first component holder, a 3D printed structure, a fluid system, and a movement system.

[0021] Another example aspect includes a system for powder removal, wherein the outer housing member can further include a pump or discharge member and a powder collection member.

[0022] Another example aspect includes a system for powder removal, wherein the outer housing member can include a rigid chamber or a more flexible system, such as a bladder, and wherein the size and volume of the outer housing member are variable.

[0023] Another example aspect includes a system for powder removal, wherein the outer housing member can provide an inert environment below the reaction limit of the material utilized by the 3D printed structure.

[0024] To achieve the foregoing and related purposes, one or more aspects include the features that are fully described hereinafter and particularly pointed out in the claims. The following description and the drawings set forth in detail certain illustrative features of one or more aspects. However, these features are only indicative of a few of the various ways in which the principles of the various aspects may be employed, and this description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a front view of an exemplary powder removal system.

[0026] Figure 2 is a side view of an exemplary robotic arm powder removal system. DETAILED DESCRIPTION

[0027] Aspects of the present disclosure are now described with reference to the drawings, wherein like reference numerals are used to refer to elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to facilitate a thorough understanding of one or more aspects of the present disclosure. However, in some or all instances, it will be apparent that any aspect described below may be practiced without the use of the specific design details described below.

[0028] Aspects of the present disclosure include a system for powder removal of three-dimensional (3D) printed structures, the system including a component holder, a fluid system, a movement system, and an environment system.

[0029] In a non - limiting example embodiment, a powder removal system may include: a component holder configured to hold a 3D printed structure or part; a fluid system configured to introduce a fluid or gas into the 3D printed structure or part to remove powder from the part; a movement system configured to move at least the 3D printed structure or part to assist the fluid or gas in moving through the 3D printed structure or to further remove powder from the 3D printed structure or part; and an environmental system that provides an inert environment for the powder removal process.

[0030] Specific reference Figure 1 , in a non - limiting example embodiment, the powder removal system 100 includes a base member 102, where the base member 102 is configured to include at least one component holder 104. The at least one component holder 104 is configured to hold the 3 - D printed component or part 106 during powder removal of the 3 - D printed component or part 106 after the part 106 has been 3 - D printed or after a portion of the part 106 has been 3 - D printed during an additive manufacturing process. The component holder 104 is configured to hold the part 106 in an initial orientation, where the initial orientation is determined relative to one or more openings leading to a hollow internal structure of the part 106 located within the part 106. The part 106 can be held by the component holder 104 using robotic gripping features, clamping features, or other holding mechanisms that can be modified to provide a passage for high - pressure gas or fluid (hereinafter referred to as "fluid") to an internal passage of the component 106 to be delivered. This ideally forms a topologically closed surface, i.e., a "manifold", rather than multiple unconnected volumes.

[0031] The powder removal system 100 may further include a fluid system. In an example embodiment, the fluid system may include an internal fluid channel 108 within a portion of the base member 102 and the component holder 104. The internal fluid channel 108 may extend from a first fluid channel end 110 located in the base member 102 to a second fluid channel end 112 located at the distal end of the component holder 104. In the described example embodiment, the component holder 104 may hold the part 106 in the initial orientation such that the second fluid channel end 112 is in fluid connection with an opening located within the part 106 that leads to the hollow internal structure of the part 106. This in turn places the fluid channel 108 in fluid communication with the hollow internal structure of the part 106. The initial orientation is further determined by considering the internal part geometry and the potential or ideal exit paths and distances of the logical sub - volumes of the internal part geometry.

[0032] In the described example embodiment, fluid may enter the internal fluid passage 108 from the fluid source 114 and then into the base member 102. The fluid source may be connected to the first fluid passage end 110. The fluid may then move through the internal fluid passage 108 that extends through the component holder 104. Then, the fluid may exit the internal fluid passage 108 at the second fluid passage end 112, which is aligned with an opening of the part 106 that leads to the hollow internal structure of the part 106. The fluid may then be pushed through the internal structure of the part 106 to remove or expel loose or excess powder located within the internal structure of the part 106. The "fluid" that may be utilized during the powder removal process may include, but is not limited to, liquids such as water, alcohol, etc., or compressed gases such as air, nitrogen, carbon dioxide, noble gases, etc., or combinations thereof.

[0033] Additionally, the internal passage 108 may be utilized to draw suction into the part 106. Thus, instead of injecting fluid into the part 106, or after injecting fluid into the part, suction may be utilized to remove powder from the internal structure of the part 106. Further, excess powder may be suctioned into the internal passage 108 through the second fluid passage end 112 and then may be discharged through the first fluid passage end 110 into an excess powder chamber.

[0034] In addition to using the internal fluid passage 108, the powder removal system 100 may alternatively or additionally utilize an external fluid source 116. In one example aspect, the external fluid source 116 may include an external nozzle 118 or a plurality of external nozzles 118. The external nozzle or nozzles 118 may be height adjustable and additionally may be movable around the plurality of openings of the part 106 when fluid is introduced into the part 106. For example, when fluid is introduced into the internal structure of the part 106 via the second fluid passage end 112 located within the component holder 104, the fluid may additionally be introduced into the internal structure of the part 106 via an external nozzle or nozzles 118 at a different opening or different plurality of openings of the internal structure of the part 106. This allows for additional removal of excess powder from the internal structure of the part 106 to ensure maximum removal of excess powder during the powder removal process. The "fluid" that may be utilized by the nozzle or nozzles 118 during the powder removal process may include, but is not limited to, liquids such as water, alcohol, etc., or compressed gases such as air, nitrogen, carbon dioxide, noble gases, etc., or combinations thereof.

[0035] In one example aspect, the external fluid source 116 can include an external nozzle 118, or alternatively or additionally can include a vacuum or other suction device. For example, fluid can be introduced into the internal structure of the part 106 via the second fluid passage end 112 and one or more external nozzles 118, and an additional vacuum can move around the part in concert with the external nozzle 118, which suctions fluid including excess powder after the fluid has moved through the internal structure of the part 106.

[0036] The external fluid source 116 can further include an external fluid source chamber or passage 132 that can be connected to each or multiple nozzles 118 and an external fluid source pump 134. The pump 134 can further include suction features to allow the nozzle 118 to both push fluid through the internal structure of the part 106 and provide suction features to remove excess fluid and powder from the internal structure of the part 106.

[0037] In a further example embodiment, the powder removal system 100 can further include a second part holder 104, or multiple additional part holders 104. Each part holder can utilize the same powder removal method as described above. For example, multiple internal fluid passages 108 can extend from a first fluid passage end 110 located in the base member 102 to a second fluid passage end 112 located at the distal end of each individual part holder 104.

[0038] As can be seen in Figure 1 the internal fluid passages 108 can extend from a first fluid passage end 110 located in the base member 102 and can branch to a second fluid passage end 112 located at the distal end of one of the multiple part holders 104, and can additionally branch to a third fluid passage end 120 located at the distal end of a different one of the multiple part holders 104, and similarly can branch to fourth and fifth fluid passage ends 122, 124 each located at the distal end of a different one of the multiple part holders 104. This allows multiple parts (which can be the same or different) to be powder removed simultaneously and utilize the same internal fluid source. Additionally, each of the multiple part holders 104 can have a corresponding external fluid source 116 that includes an external nozzle or multiple external nozzles 118 and a vacuum.

[0039] The powder removal system 100 may further include a movement system. The movement system is configured to move at least the 3D printed structure 106 or the fluid system described above according to a movement program based on the configuration of the hollow portion of the 3D printed structure 106. The movement system 100 may be configured to move the base member 102, which in turn may move one or more component holders 104. The movement of the base member may include, but is not limited to, rotating the base member 102 or vibrating the base member 102, thereby rotating or vibrating the plurality of component holders 104 and the part 106. Thus, when the fluid system described above is introducing fluid into the part 106, the base member 102 may rotate or vibrate. For example, when the fluid is moving through the internal components of the part 106, the base member may rotate and vibrate simultaneously to further move the fluid through the internal components of the part 106 and loosen any excess powder that may be stuck or otherwise resident within the internal components of the part 106.

[0040] Similarly, each individual component holder 104 among the plurality of component holders 104 is configured to be movable. In one example embodiment, each individual component holder 104 among the plurality of component holders 104 may be movable similar to a robotic arm or may be rotatable to change the orientation of the internal components of the part 106, thereby further moving the fluid through the internal components of the part 106 and loosening any excess powder within the part 106. For example, when the fluid is moving through the internal components of the part 106 and the base member 102 may rotate and vibrate simultaneously, each individual component holder 104 among the plurality of component holders 104 may move simultaneously to change the orientation of the part 106. This combination of the fluid system described above with the movement system of the base member 102 and the movement system of each individual component holder 104 among the plurality of component holders allows for the efficient removal of powder from the internal components of the part 106.

[0041] The powder removal system 100 may further include a sensor assembly or sensor system. The sensor system may be utilized to verify the success of the powder removal process, including but not limited to: determining the weight of the part and the weight of the waste container, mass flow sensors, vision-based sensors (such as cameras), etc. The sensor system may assist the powder removal system 100 in determining whether one or more parts 106 require additional powder removal through any combination of the fluid system, the movement system of the base member 102, and the movement system of each individual component holder 104. If an excessive amount of excess powder is determined to be present within the internal components of the part 106 through one of the sensing methods described above, additional powder removal may occur at any one or all of the parts 106 located at each of the individual component holders 104.

[0042] Additionally, the sensor system can be utilized to determine the optimal orientation of one or more parts 106 fixed to their respective part holders 104 to most efficiently deflate the internal components of one or more parts 106. More specifically, sensors coupled to a processor can determine an initial orientation and then can inform the deflation system 100 of a programmed movement of the components that further takes into account the internal part geometry as well as the potential or ideal exit paths and distances of logical sub-volumes of the internal part geometry.

[0043] The deflation system 100 can further include a housing and an environmental system. The environmental system can include an outer housing member 126, which can further include a rigid chamber or a more flexible system, such as a blister surrounding a plurality of part holders 104 and a base member 102. Such an environmental system allows a highly customizable inert environment to best suit each specific application for which the deflation system may be used. For example, an inert environment below the reaction limit of the material being processed can be utilized. Generally, the low oxygen content of reactive metals is 2% or less, and due to special processing conditions, some equipment operations require even less. Additionally, the volume of the housing can be adjustable to fit a specific application. For example, larger-sized parts can utilize a larger volume of the outer housing member 126. This can be more efficient because the environment can be highly customizable for each individual application of the outer housing member 126.

[0044] The environmental system can further include a pump or discharge mechanism 128. The discharge mechanism can be used to seal the outer housing member 126 and also to collect excess powder and fluid during the deflation process. Additionally, the discharge device can be connected to a powder reservoir 130, which can collect the excess fluid and powder, so that the powder can be filtered for subsequent applications.

[0045] Referring to additional examples as can be seen in Figure 2 the deflation system 100 can further include a base member 102 and a part holder 104, which can be in the form of a robotic arm. The base member 102 and the part holder 104 of the robotic arm will similarly include robotic gripping features to hold the part 106 and can be modified to provide internal channels 108 for high-pressure gas or fluid. The robotic arm mechanism will include the same fluid system and environmental system as described above and can additionally include the same movement of the base member.

[0046] Referring to another additional example, referring to Figure 1Each of the described multiple part holders 104 can be interchangeable with the robotic arm. This can allow for different ranges of motion of the corresponding part 106. This additional example can be used for more complex parts that may require a higher degree of powder removal.

[0047] Further, each of the powder removal systems described above with respect to Figure 1 can be applied to a standard robotic arm additive manufacturing process. This will allow powder removal to occur consistently with the 3-D printing process of parts 106 that include complex internal structures, which may not be possible in current powder removal practices.

Claims

1. A system for powder removal from a three-dimensional (3D) printed structure, comprising: A first component holder configured to removably hold the 3D printed structure in an initial orientation relative to at least one opening leading to a hollow portion within the 3D printed structure; A fluid system configured to control a fluid to at least apply the fluid to the hollow portion or remove the fluid from the hollow portion to remove powder from the hollow portion; And A movement system configured to move at least the 3D printed structure or the fluid system according to a movement program based on the configuration of the hollow portion.

2. The system according to claim 1, wherein The fluid system includes an internal fluid channel within a portion of the component holder, wherein the internal fluid channel is in fluid connection with a first opening leading to the hollow portion when the 3D printed structure is fixed to the component holder, such that the fluid flows through the portion of the component holder and the first opening to at least apply the fluid to the hollow portion or remove the fluid from the hollow portion.

3. The system according to claim 1, further comprising a second component holder configured to removably hold a second 3D printed structure in a second initial orientation relative to at least one opening leading to a hollow portion within the second 3D printed structure, wherein, The fluid system is further configured to at least apply the fluid to the hollow portion of a second 3D printed structure or remove the fluid from the hollow portion of the second 3D printed structure, and the movement system is further configured to move at least the second 3D printed structure or the fluid system according to a movement program based on the configuration of the hollow portion of the second 3D printed structure.

4. The system according to claim 3, wherein The fluid system includes a first internal fluid channel within a portion of the first component holder and a second internal fluid channel within a portion of the second component holder, wherein the first internal fluid channel and the second internal fluid channel are connected to each other.

5. The system according to claim 1, further comprising a rigid structure connecting the component holder and the second component holder, wherein, The movement system is configured to move the rigid structure such that the component holder and the second component holder move simultaneously.

6. The system according to claim 1, wherein The movement program of the movement system includes vibration and rotation, which are configured to be applied to the 3D printed structure in a combined form based on the configuration of the hollow portion.

7. The system according to claim 1, further comprising: A sensor system configured to sense at least the amount of the powder or the fluid located within the hollow portion and at least adjust the control of the fluid by the fluid system and the control of the movement by the movement system based on the sensed amount.

8. The system according to claim 1, wherein The component holder is configured to be fixed to a 3-D printing build plate.

9. The system according to claim 1, further comprising an external fluid source including one or more nozzles configured to apply a fluid to the hollow portion of the 3D printed structure at least at a second opening leading to the hollow portion within the 3D printed structure.

10. The system according to claim 8, wherein, The external fluid source is movable around the 3D printed structure to apply the fluid to the hollow portion of the 3D printed structure at a plurality of different openings leading to the hollow portion within the 3D printed structure.

11. The system according to claim 9, wherein, The plurality of nozzles can be configured to apply fluid to hollow portions of a plurality of different 3D printed structures located on a plurality of different component holders.

12. The system according to claim 1, further comprising an outer housing member configured to house and enclose at least the first component holder, the 3D printed structure, the fluid system, and the movement system.

13. The system according to claim 12, wherein, The outer housing member can further include a pump or discharge member and a powder collection member.

14. The system according to claim 12, wherein, The outer housing member can include a rigid chamber or a more flexible system, such as a bladder, and wherein the size and volume of the outer housing member are variable.

15. The system according to claim 12, wherein, The outer housing member is capable of providing an inert environment below the reaction limit of the materials utilized by the 3D printed structure.

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