Metal 3D printing systems for using sand as supports
11691202 · 2023-07-04
Assignee
Inventors
Cpc classification
B33Y10/00
PERFORMING OPERATIONS; TRANSPORTING
B22F12/55
PERFORMING OPERATIONS; TRANSPORTING
B33Y70/00
PERFORMING OPERATIONS; TRANSPORTING
B22F10/14
PERFORMING OPERATIONS; TRANSPORTING
B22F12/224
PERFORMING OPERATIONS; TRANSPORTING
B22F2999/00
PERFORMING OPERATIONS; TRANSPORTING
B22F12/41
PERFORMING OPERATIONS; TRANSPORTING
B29C64/393
PERFORMING OPERATIONS; TRANSPORTING
B22F12/41
PERFORMING OPERATIONS; TRANSPORTING
B33Y50/02
PERFORMING OPERATIONS; TRANSPORTING
B28B1/001
PERFORMING OPERATIONS; TRANSPORTING
B22F10/14
PERFORMING OPERATIONS; TRANSPORTING
B33Y30/00
PERFORMING OPERATIONS; TRANSPORTING
B22F12/55
PERFORMING OPERATIONS; TRANSPORTING
B22F10/85
PERFORMING OPERATIONS; TRANSPORTING
B22F10/28
PERFORMING OPERATIONS; TRANSPORTING
B22F12/222
PERFORMING OPERATIONS; TRANSPORTING
B22F12/224
PERFORMING OPERATIONS; TRANSPORTING
B22F10/25
PERFORMING OPERATIONS; TRANSPORTING
B28B1/001
PERFORMING OPERATIONS; TRANSPORTING
B22F2999/00
PERFORMING OPERATIONS; TRANSPORTING
B29C64/379
PERFORMING OPERATIONS; TRANSPORTING
Y02P10/25
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B29C64/153
PERFORMING OPERATIONS; TRANSPORTING
International classification
B22F10/14
PERFORMING OPERATIONS; TRANSPORTING
B22F10/85
PERFORMING OPERATIONS; TRANSPORTING
B22F12/00
PERFORMING OPERATIONS; TRANSPORTING
B22F12/41
PERFORMING OPERATIONS; TRANSPORTING
B29C64/153
PERFORMING OPERATIONS; TRANSPORTING
B29C64/379
PERFORMING OPERATIONS; TRANSPORTING
B29C64/393
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A 3-dimensional printing system for manufacturing a part is provided. The system includes a building platform having a deposited pattern of metal powder, a sand dispensing nozzle selectively supplying sand to the building platform, a binder dispensing nozzle selectively supplying binder material to the building platform, a robotic arm supporting one or more of the sand dispensing nozzle and the binder dispensing nozzle, the robotic arm moving the one or more of the sand dispensing nozzle and the binder dispensing nozzle, and a processor controlling the robotic arm to position the one or more of the sand dispensing nozzle and the binder dispensing nozzle relative to the deposited pattern of metal powder and control the sand dispensing nozzle and the binder dispensing nozzle to supply powdered sand and binder, respectively, based on a Computer Aided Drafting file associated with the part.
Claims
1. A 3-dimensional (3D) printing system for manufacturing a part, the system comprising: a building platform having a selectively deposited pattern of metal powder; a sand dispensing nozzle configured to selectively supply powdered sand to the building platform; a binder dispensing nozzle configured to selectively supply binder material to the building platform; a robotic arm configured to support one or more of the sand dispensing nozzle and the binder dispensing nozzle, the robotic arm moving the one or more of the sand dispensing nozzle and the binder dispensing nozzle; a processor controlling the robotic arm to position the one or more of the sand dispensing nozzle and the binder dispensing nozzle relative to the selectively deposited pattern of metal powder and control the sand dispensing nozzle and the binder dispensing nozzle to supply powdered sand and binder, respectively, based on a Computer Aided Drafting file associated with the part; a metal powder stock located adjacent to the building platform; a roller positioned to spread metal powder from the stock across the building platform to form the selectively deposited pattern of metal powder; and a focused energy source located on the robotic arm, wherein the processor controls the focused energy source to apply heat to the selectively deposited pattern of metal powder.
2. The 3D printing system of claim 1, wherein the sand dispensing nozzle and the binder dispensing nozzle are all located on the robotic arm, wherein the processor controls the robotic arm to position selectively deposited sand and binder based on the Computer Aided Drafting file associated with the part.
3. The 3D printing system of claim 1, further comprising a powder scraper positioned above the building platform and configured to remove excess powder material from the selectively deposited pattern of metal powder prior to deposition of additional metal powder.
4. The 3D printing system of claim 1, wherein the building platform may be selectively lowered, and wherein the processor selectively controls the building platform to lower the building platform as the part is printed.
Description
BRIEF DESCRIPTION OF DRAWINGS
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DETAILED DESCRIPTION
(12) The following detailed description provides details of the figures and embodiments of the present application. Reference numerals and descriptions of redundant elements between figures are omitted for clarity. Terms used throughout the description are provided as examples and are not intended to be limiting. For example, the use of the term “automatic” may involve fully automatic or semi-automatic implementations involving user or administrator control over certain aspects of the implementation, depending on the desired implementation of one of ordinary skill in the art practicing implementations of the present application. Selection can be conducted by a user through a user interface or other input means, or can be implemented through a desired algorithm. Embodiments as described herein can be utilized either singularly or in combination and the functionality of the embodiments can be implemented through any means according to the desired implementations.
(13) As described above, support structures can be important for metal 3DP processes including Powder Bed Fusion (PBF) and metal Direct Energy Deposition (DED) processes. As the complexity of the printed parts increases, the likelihood of encountering a multitude of these features in a component increases as well. Additionally, the support structure may be necessary to resist deformation or even collapse caused by gravity as the fabrication of the component proceeds and can also limit the effects caused by generated thermal gradients during the process and shrinkage upon solidification to help to reduce thermal distortion that can potentially lead to cracking, curling, sagging, delamination and shrinkage.
(14) Therefore, support structures enable the 3DP of complex components. However, these support structures need to be removed after printing and can result in a potential increase in material consumption, energy usage and the amount of work for manual post-processing required to produce the final part.
(15) The need to remove the support structures in metal 3DP is one factor that may have prevented 3DP being adopted for mass production so far. Often metal 3DP is used only for rapid prototyping, which has lower standards or less quality requirements for the finish. However, in real production, quality of surface finish plays an important role as the function of the part.
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(17) Considering the drawbacks that support structure may bring to metal 3DP, especially in PBF and DED, example implementations may provide novel methods of building the support structures in metal 3DP. Example implementations of the present disclosure may use sand powder (SiO.sub.2) as the support structure material instead of any types of metal powders. Sand has been applied in metal casting for a long history and has performed well in other types of metal casting processes. Sand has stable chemical properties and a completely different nature from metal powder. Thus, sand provides a more improved support structure material than metal powders in 3DP processes.
(18) In some example implementations, a 3DP manufacturing system may be modified to change the supporting materials from metal powder to sand. In a first type of modification, referred to herein as “Building Sand Support in Printing”, the 3DP system may be modified to position sand alongside the positioned metal powder. In a second type of modification, referred to herein as “Pre-Printed Sand Support”, sand support features may be printed in advance of the positioning of the metal particles. Each of these types of modifications is discussed in greater detail below.
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(20) As illustrated in
(21) As the metal powder, sand and binder are placed layer by layer, the laser or electron beam 408 melts or welds the metal powder to form a completely dense solid. Specifically, during the printing process in PBF system 402, the metal powder, sand, and binder are spread on the building platform 420. The beam of the heat source (laser or electron beam 408) will selectively melt or sinter the first layer of metal powder but not affect the sand and binder. Then the depth of the building platform 420 is lowered by one layer and additional metal powder, sand and binder applied to the next layer by the nozzles 410, 414 and 416. The melting process is repeated layer by layer. After printing, sand powder and metal powder may need to be separated to reduce material waste. For example, magnetic metal powder may be used to facilitate separation of the metal powder from the sand.
(22) As illustrated in
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(26) As discussed briefly above, sand has historically been used in the casting industry because of numerous advantages including being inexpensive, easily recycled, and heat resistant and capable of withstanding extremely high temperature. Initially, green sand (an aggregate of sand, pulverized coal, bentonite clay, and water) was traditionally used in sand casting, but modern chemically bonded molding systems have become more widely used. A frequently used casting sand is Silicon Oxide or Silica (SiO.sub.2).
(27) Recently, 3D printing foundry sand (e.g., silica sand) has become available in some 3DP systems. During the 3D sand printing process, silica sand is applied in layers and selectively bonded with a binder until the desired shape is formed. According to different applications, a variety of binders can be selected, such as furan, phenolic resins, inorganic binders, or any other binder that might be apparent to a person of ordinary skill in the art as nearly all types of binders used in casting foundries may be used as binders in 3DP in accordance with example implementations of the present application.
(28) A process of 3D printing a sand core (e.g., sand core 502) is similar to metal printing, including 1) transferring a Computer Aided Drafting (CAD) file or CAD data to sand printing machine, 2) spreading a layer of sand powder in a building plate or platform, 3) selectively spreading binder on sand, 4) lowering the building platform, 5) repeating the previous process until the final shape is achieved, and 6) removing the unbound powder and finish part building. This process may be used to pre-print the sand core prior to printing the metal product or printing the sand core in parallel with printing the metal product.
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(30) Additionally, the printing process may also be modified to facilitate building a layer of the sand support structure 454 between printing layers of the metal part 412. In other words, a layer of the part 412 may be printed from metal powder dispensed from the nozzle 410. Before any metal powder is dispensed for a new, subsequent layer, the system 402 will automatically determine whether there is a need to build support in this layer based on the CAD file. If no support structure is required, the next layer of part 412 will be printed using the metal powder from the nozzle 410 followed by selectively binding/melting the powder by focused energy source (e.g., laser or electron beam 408). Conversely, if a support structure 454 is required, robotic arms 418 will be utilized to position nozzle 410 to supply metal powder at specific locations. The robotic arms 418 may also be used to position nozzles 414 and 416 to supply a new layer of sand powder selectively on desired locations and to supply binders selectively on the layer of sand powder. The focused energy source (e.g., laser or electron beam 408) may then be used as normal to melt or sinter the metal powder. The whole process will be repeated until the final parts are built. In some example implementations, metal layers having no supporting structures may form a roller feeding metal powder from the powder stock onto the building platform similar to powder roller 112 of the related art system 100.
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(33) The PBF system 800 includes a sand supply nozzle 814, a binder supply nozzle 812 and a metal powder supply nozzle 820, each nozzle mounted on a computer controlled robotic arm 806. As illustrated, a separate robotic arm 806 may be provided for each of the sand supply nozzle 814, the binder supply nozzle 812 and the metal powder supply nozzle 820. However, example implementations of the present application may include a single robotic arm supporting more than one of the sand supply nozzle 814, the binder supply nozzle 812 and the metal powder supply nozzle 820.
(34) The robotic arm 806 may be controlled by one or more motion controllers 808 communicatively coupled to a computing device 810 controlling the 3DP process. The computing device 810 may be a computing device 1005 of the computing environment 1000 discussed below with respect to
(35) As illustrated in
(36) Further, as illustrated in
(37) As illustrated in
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(39) Instead of printing a sand support structure 902 simultaneously with the printing of the metal parts, the support structure 902 may be printed in advance using sand and binding agent in any suitable printing systems. The sand support 902 may be a single unitary piece or may be formed from several pieces printed separately as desired. As illustrated in
(40) In some example implementations, the robotic arms 906 may be controlled by one or more motion controllers 908 communicatively coupled to a computing device 910 controlling the 3DP process. The computing device 910 may be a computing device 1005 of the computing environment 1000 discussed below with respect to
(41) As illustrated in
(42) In some example implementations, over accumulated powder has to be removed by a brush, scraper or other similar tool before any printing on top of the support structure 902. This is due to when building the part 918 beside the support structure 902, the powder roller 912 may add metal powder on top of support structure 902. Though a PBF process is illustrated in
(43) The example implementations described herein feature sand support structures. In the related art, support structures normally need to be removed during post-processing. In the related art, most of soluble supports are removed by hand or using flush cutters. Sometimes there may be lattice structures that can be difficult to remove and may cause damage to the printing part if located in critical locations. Further, surfaces after supports are removed sometimes have a lower printing quality and rough surface finish. In example implementations, using sand as material for building the support structure, post processing can become easy and surface finish can also be significantly improved.
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(45) Computing device 1005 can be communicatively coupled to input/interface 1035 and output device/interface 1040. Either one or both of input/interface 1035 and output device/interface 1040 can be a wired or wireless interface and can be detachable. Input/interface 1035 may include any device, component, sensor, or interface, physical or virtual, which can be used to provide input (e.g., buttons, touch-screen interface, keyboard, a pointing/cursor control, microphone, camera, braille, motion sensor, optical reader, and/or the like).
(46) Output device/interface 1040 may include a display, television, monitor, printer, speaker, braille, or the like. In some example implementations, input/interface 1035 (e.g., user interface) and output device/interface 1040 can be embedded with, or physically coupled to, the computing device 1005. In other example implementations, other computing devices may function as, or provide the functions of, an input/interface 1035 and output device/interface 1040 for a computing device 1005. These elements may include, but are not limited to, well-known AR hardware inputs so as to permit a user to interact with an AR environment.
(47) Examples of computing device 1005 may include, but are not limited to, highly mobile devices (e.g., smartphones, devices in vehicles and other machines, devices carried by humans and animals, and the like), mobile devices (e.g., tablets, notebooks, laptops, personal computers, portable televisions, radios, and the like), and devices not designed for mobility (e.g., desktop computers, server devices, other computers, information kiosks, televisions with one or more processors embedded therein and/or coupled thereto, radios, and the like).
(48) Computing device 1005 can be communicatively coupled (e.g., via I/O interface 1025) to external storage 1045 and network 1050 for communicating with any number of networked components, devices, and systems, including one or more computing devices of the same or different configuration. Computing device 1005 or any connected computing device can be functioning as, providing services of, or referred to as a server, client, thin server, general machine, special-purpose machine, or another label.
(49) I/O interface 1025 can include, but is not limited to, wired and/or wireless interfaces using any communication or I/O protocols or standards (e.g., Ethernet, 802.11xs, Universal System Bus, WiMAX, modem, a cellular network protocol, and the like) for communicating information to and/or from at least all the connected components, devices, and networks in computing environment 1000. Network 1050 can be any network or combination of networks (e.g., the Internet, local area network, wide area network, a telephonic network, a cellular network, satellite network, and the like).
(50) Computing device 1005 can use and/or communicate using computer-usable or computer-readable media, including transitory media and non-transitory media. Transitory media includes transmission media (e.g., metal cables, fiber optics), signals, carrier waves, and the like. Non-transitory media includes magnetic media (e.g., disks and tapes), optical media (e.g., CD ROM, digital video disks, Blu-ray disks), solid state media (e.g., RAM, ROM, flash memory, solid-state storage), and other non-volatile storage or memory.
(51) Computing device 1005 can be used to implement techniques, methods, applications, processes, or computer-executable instructions in some example computing environments. Computer-executable instructions can be retrieved from transitory media, and stored on and retrieved from non-transitory media. The executable instructions can originate from one or more of any programming, scripting, and machine languages (e.g., C, C++, C #, Java, Visual Basic, Python, Perl, JavaScript, and others).
(52) Processor(s) 1010 can execute under any operating system (OS) (not shown), in a native or virtual environment. One or more applications can be deployed that include logic unit 1055, application programming interface (API) unit 1060, input unit 1065, output unit 1070, CAD Processing unit 1075, Nozzle Control Unit 1080, Focused Energy Source Control unit 1085 and inter-unit communication mechanism 1095 for the different units to communicate with each other, with the OS, and with other applications (not shown).
(53) For example, CAD Processing unit 1075, Nozzle Control Unit 1080, and Focused Energy Source Control unit 1085 may control 3DP systems in accordance with example implementations of the present application and perform processes and operations in accordance with example implementations of the present application. The described units and elements can be varied in design, function, configuration, or implementation and are not limited to the descriptions provided.
(54) In some example implementations, when information or an execution instruction is received by API unit 1060, it may be communicated to one or more other units (e.g., CAD Processing unit 1075, Nozzle Control Unit 1080, and Focused Energy Source Control unit 1085). For example, the CAD processing unit 1075 may process a CAD file associated with a part to be printed by the 3DP system and partition the CAD file into individual slice layers. Further, the CAD processing unit 1075 may also determine locations where metal powder, sand, and binder should be deposited to form the individual slice layers of the part. The nozzle control unit 1080 may control the motion controllers to position the nozzles (e.g., a metal supply nozzle, a sand supply nozzle, and a binder supply nozzle) based on the processing done by the CAD file processing unit. Further, the focused energy source control unit 1085 may control a high powered focused energy source (e.g., a laser or an electron beam) to melt the powdered metal deposited by the metal supply nozzle to form the part layer by layer.
(55) In some instances, the logic unit 1055 may be configured to control the information flow among the units and direct the services provided by API unit 1060, CAD Processing unit 1075, Nozzle Control Unit 1080, and Focused Energy Source Control unit 1085 in some example implementations described above. For example, the flow of one or more processes or implementations may be controlled by logic unit 1055 alone or in conjunction with API unit 1060.
(56) Although a few example implementations have been shown and described, these example implementations are provided to convey the subject matter described herein to people who are familiar with this field. It should be understood that the subject matter described herein may be implemented in various forms without being limited to the described example implementations. The subject matter described herein can be practiced with those specifically defined or described matters or with other or different elements or matters not described. It will be appreciated by those familiar with this field that changes may be made in these example implementations without departing from the subject matter described herein, as defined in the appended claims and their equivalents.