Printing Cartridge for Additive Manufacturing

Abstract

A cassette for a manufacturing system includes a sealable chamber having a bed and a laser transparent window. A powder hopper may be positioned within the sealable chamber. A powder dispenser is positioned within the sealable chamber for dispensing powder from the powder hopper onto the bed.

Description

[0001] Related Applications

[0002] This disclosure is part of a non - provisional patent application claiming the benefit of priority of U.S. Patent Application No. 63 / 030,757, filed May 27, 2020, which is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure generally relates to systems and methods for high - volume additive manufacturing. In one embodiment, powder bed fusion manufacturing is supported by using discrete print cartridges.

[0004] Background

[0005] Traditional component machining typically relies on removing material by drilling, cutting, or grinding to form a part. In contrast, additive manufacturing (also known as 3D printing) generally involves continuously adding material layer - by - layer to build a part. Starting from a 3D computer model, additive manufacturing systems can be used to form complex parts from a variety of materials.

[0006] An additive manufacturing technique called powder bed fusion (PBF) uses one or more focused energy sources, such as lasers or electron beams, to draw patterns in thin layers of powder by melting the powder and bonding it to the underlying layer to gradually form a 3D - printed part. The powder can be plastic, metal, glass, ceramic, crystal, other meltable materials, or a combination of meltable and non - meltable materials (i.e., plastic and wood or metal and ceramic). This technique is very precise and can typically achieve feature sizes as small as 150um - 300um. However, industrial additive manufacturing systems can be cumbersome to operate and typically require workers to wear protective equipment (such as respirators, safety glasses, special uniforms) when performing normal daily tasks (such as removing the 3D - printed part, cleaning the print chamber, or maintaining worn items).

[0007] Some additive manufacturing systems attempt to improve the convenience and safety of maintenance by sealing the 3D print in a box. After the additive manufacturing system has completed printing, the box can be removed from the machine. Unfortunately, it can be difficult to form a perfect seal between the printer and the sealed box, and thus some powder is always present outside the print chamber. This can expose the operator to inhalation hazards.

[0008] Before the next 3D printing can begin, the additive manufacturing system may also require a significant amount of time to remove the 3D print, clean, and maintain the printer. Even if the 3D print is sealed in a box, the print chamber may still need to be manually cleaned and any worn items (e.g., spreader blades, etc.) need to be manually replaced and realigned. Since printing is inherently a dirty process (in this case, dirt refers to soot, unused powder, slag, etc.), everything in the print chamber, including spreader blades, the air flow duct system, the glass window, the spreader drive mechanism, may be covered with dirt. Since it is very important to ensure the purity of the printing powder used, it is crucial to thoroughly clean the print chamber and the gas duct system before changing materials. This requires a deep clean, which typically involves disassembling many components so that the dirt can be removed. This work cannot be done through the glove port and may require specially trained labor wearing protective equipment such as respirators.

[0009] Another problem comes from 3D prints that require an inert gas environment. Whenever the print chamber is opened to atmospheric air, the print chamber must be evacuated and purged. This process takes a significant amount of time and results in the loss of expensive inert gas. These activities can also take a significant amount of time, reducing the throughput of additive manufacturing because new 3D printing generally cannot start until the cleaning and maintenance are completed.

[0010] When the 3D print is removed from the print chamber, the additive manufacturing system may also require the 3D print to be removed from the controlled printing environment. This can have an adverse effect on 3D prints that require a heat treatment furnace for post-processing cooling and / or subsequent stress relief, annealing, or heat treatment. While the additive manufacturing system can preheat the print bed and / or maintain the print at a set temperature during printing in the print chamber, temperature control is generally not available outside the print chamber. Unfortunately, when the 3D print is removed from the print chamber, these 3D prints are generally not temperature-controlled and, in many systems, are also exposed to uncontrolled air. These factors can affect the material properties of the 3D print. In addition, 3D prints are usually too hot to be immediately removed from the print chamber, so they must remain in the print chamber for several hours after they are completed printing. This ties up the print chamber and prevents the system from starting a new print job.

[0011] Overview

[0012] A cassette for a manufacturing system includes a sealable chamber having a bed and a laser transparent window. A powder hopper may be positioned within the sealable chamber. A powder spreader is positioned within the sealable chamber for dispensing powder from the powder hopper onto the bed.

[0013] In some embodiments, the laser transparent window is positioned to allow an external camera to focus on the bed within the sealable chamber.

[0014] In some embodiments, the sealable chamber supports a camera to focus on the bed within the sealable chamber.

[0015] In some embodiments, a wipe blade may be mounted within the sealable chamber to clean the laser transparent window.

[0016] In some embodiments, a bellows is attached to the sealable chamber to hold the laser transparent window.

[0017] In another embodiment, a cartridge for a manufacturing system includes a sealable chamber having a bed and a laser transparent window. A powder hopper is positioned within the sealable chamber. A powder dispenser may be positioned within the sealable chamber for dispensing powder from the powder hopper onto the bed, and an electronic memory is attached to the cartridge to store electronic information for identifying the cartridge and controlling the operation of a printing station.

[0018] In another embodiment, a cartridge for a manufacturing system includes a sealable chamber having a bed and a laser transparent window. A powder hopper is positioned within the sealable chamber. The powder dispenser is positioned to dispense powder from the powder hopper onto the bed. A bellows may be attached to the sealable chamber to hold the laser transparent window.

[0019] In another embodiment, a cartridge for a manufacturing system includes a sealable chamber having a bed and a laser transparent window. A powder hopper is positioned within the sealable chamber. A powder dispenser is positioned within the sealable chamber for dispensing powder from the powder hopper onto the bed, and a wiper mechanism is configured to periodically clean the interior of the laser transparent window.

[0020] In another embodiment, an additive manufacturing system includes a printing station that includes a laser system and a cartridge attachment mechanism. A cartridge is attachable to the printing station, the cartridge having a sealable chamber having a bed and a laser transparent window for allowing laser energy from the laser system of the printing station to pass therethrough. The cartridge further includes a powder hopper positioned within the sealable chamber.

[0021] In another embodiment, an additive manufacturing system includes a printing station that includes a laser system and a cartridge attachment mechanism. A cartridge is attachable to the printing station, the cartridge having a sealable chamber having a bed and a laser transparent window for allowing laser energy from the laser system of the printing station to pass therethrough. The cartridge further includes gas inlet and outlet ports to allow control of the cartridge gas environment.

[0022] In another embodiment, the additive manufacturing system includes a printing station that includes a laser system and a cartridge attachment mechanism. A cartridge is attachable to the printing station and has a sealable chamber that has a bed and a laser-transparent window through which laser energy from the laser system of the printing station passes. An electronic memory is attached to the cartridge to store electronic information for identifying the cartridge and controlling the operation of the printing station.

[0023] In another embodiment, the additive manufacturing system includes a printing station that includes a laser system and a cartridge attachment mechanism. A cartridge is attachable to the printing station and has a sealable chamber that has a bed and a laser-transparent window through which laser energy from the laser system of the printing station passes. The cartridge further includes a bellows attached to the sealable chamber to hold the laser-transparent window.

[0024] In another embodiment, the additive manufacturing system includes a main cartridge and an auxiliary cartridge, where each cartridge has a sealable chamber that has a bed and a laser-transparent window through which the laser energy system of the printing station passes. A printing station including a cartridge attachment mechanism is available for holding the main cartridge and the auxiliary cartridge, and the laser system is configurable to direct a first portion of light through the laser-transparent window into the main cartridge and further direct an unused portion of the light in the main cartridge through the laser-transparent window into the auxiliary cartridge.

[0025] In another embodiment, the additive manufacturing system includes a printing station that includes a laser system capable of providing a two-dimensional laser image and has a cartridge attachment mechanism. A cartridge is attachable to the printing station and has a sealable chamber that has a bed and a laser-transparent window through which two-dimensional laser energy from the laser system of the printing station passes.

[0026] In another embodiment, the additive manufacturing system includes a plurality of printers and a plurality of cartridges attachable to the printers. At least one cartridge further includes a sealable chamber having a bed and a laser-transparent window. Another system is available for storing and moving the plurality of cartridges.

[0027] In some embodiments, at least one of the plurality of cartridges has a powder hopper and a powder spreader positioned within the sealable chamber to dispense powder from the powder hopper onto the bed.

[0028] In some embodiments, the system for storing and moving the plurality of cartridges further includes a cartridge storage rack.

[0029] In some embodiments, at least one of the plurality of cartridges further includes an electronic memory attached to store electronic information for identifying the cartridge. The system for storing and moving the plurality of cartridges can locate the cartridge based on the electronic information.

[0030] In some embodiments, the system for storing and moving multiple cartridges is automated.

[0031] In some embodiments, at least some of the printer, the cartridges, and the system for storing and moving multiple cartridges support wireless communication therebetween.

[0032] In some embodiments, powder is added to or removed from a powder station.

[0033] In some embodiments, at least one cartridge is inverted at the powder station to remove powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The non-limiting and non-exhaustive embodiments of the present disclosure are described with reference to the following drawings, in which like reference numerals refer to like parts throughout the various views unless otherwise specified.

[0036] Figure 1A A print cartridge for an additive manufacturing system is shown in partial cross-section;

[0037] Figure 1B A transporter for a print cartridge is shown;

[0038] Figure 1C Installing a print cartridge in a print station of an additive manufacturing system is shown;

[0039] Figure 1D A print cartridge interface is shown;

[0040] Figure 1E A print cartridge storage shelf is shown;

[0041] Figure 1F The use of an auxiliary print engine is shown;

[0042] Figure 1G An eight-system work cell factory layout is shown;

[0043] Figure 1H An alternative embodiment of a print cartridge is shown that is capable of interacting with an X-Y gantry that can traverse the entire area of a printing plate in the print cartridge;

[0044] Figure 1I An alternative embodiment of a print cartridge with a bellows connection is shown;

[0045] Figure 1J An alternative embodiment of a print cartridge with a bellows connection and an auxiliary X-Y gantry is shown;

[0046] Figure 1K An alternative embodiment of a print cartridge with a bellows connection and a print head that is connected to push and move a window is shown;

[0047] Figure 1L Illustrates the concept of a wiper blade that keeps the laser input window clean;

[0048] Figure 1M Illustrates an alternative embodiment of an additive manufacturing system with a fixed window;

[0049] Figure 1N Illustrates in the open position Figure 1M of an alternative embodiment;

[0050] Figure 1O Illustrates the control of the printing facilities at each station;

[0051] Figure 1P Illustrates an additive manufacturing system;

[0052] Figure 2 Illustrates a method for operating a cartridge-based additive manufacturing system;

[0053] Figure 3 Illustrates a cartridge-based additive manufacturing system capable of providing a one-dimensional or two-dimensional light beam to a cartridge; and

[0054] Figure 4 Illustrates a method of operating a cartridge-based additive manufacturing system capable of providing a one-dimensional or two-dimensional light beam to a cartridge.

[0055] Detailed description

[0056] In the following description, reference is made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific exemplary embodiments in which the present disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the concepts disclosed herein, and it should be understood that various disclosed embodiments may be modified and other embodiments may be utilized without departing from the scope of the present disclosure. Accordingly, the following detailed description should not be construed as limiting.

[0057] Figure 1A Illustrates in partial cross-section a 3D printing cartridge 1A for an additive manufacturing system. The 3D printing cartridge (hereinafter referred to as "cartridge") separates all "dirty" printing functions from the rest of the system and the operator environment and is designed for replacement or removal. "Dirty" refers to any situation where powder is present, being processed for printing, or soot is generated. Whenever the cartridge 1A is connected to a mating device such as a station (printer, deflashing machine, or storage station) described later, the mating device can supply the services required to operate the cartridge based on the station to which it is mated as needed (e.g., the printer station allows full control of the cartridge, while the storage station can only provide heating, power, and gas recovery as well as the use of cameras and lights). The cartridge 1A is designed to be sealed when disconnected from the mating station.

[0058] The cartridge 1A is constructed around a bed or substrate 24A. Fresh powder for new prints is stored in a powder hopper 2A, which can have a capacity to store all the powder required for a full volume print. The fresh powder is metered onto the substrate 24A through a powder gate 23A. The powder is swept across the plate by a powder spreader 4A using a powder spreading wiper. A powder spreader drive 5A moves the powder spreader back and forth across the print plate 12A.

[0059] A window 3A seals the top of the cartridge 1A, preventing powder or gas leakage and allowing a laser beam (not shown) to pass through the window to weld the powder. The window 3A allows access to the cartridge for loading the print plate, unloading the print, cleaning, and maintaining cartridge components (seals, spreading wipers, etc.). The interior of the cartridge 1A can be illuminated and imaged by a camera and lights 22A. The camera and lights can be located inside or outside the sealed chamber, or both inside and outside the sealed chamber, and can be positioned to take pictures and / or focus on a scene inside the cartridge, particularly a scene on the print plate. The camera and lights can also be mounted on a motion platform, allowing the user to pan or zoom in on items of interest during printing. The camera can be used in conjunction with auxiliary print diagnostic devices (such as pyrometers, motion detectors, photodiodes, thermal cameras, or other sensors) to automatically detect events and pan / zoom the camera to focus on a location of interest. In some embodiments, the operator can view the camera image in an electronic or virtual window rather than directly through a physical port or window in the cartridge.

[0060] An inert gas can be supplied to the cartridge through a gas supply conduit 6A so that printing can be performed in any atmosphere that is most favorable for each print. A gas return conduit 7A removes the inert gas. The gas passes through a HEPA filter 8A that removes impurities (soot, suspended nanoparticles of powder, etc.). The gas then travels to a gas recycler (not shown) mounted on mating equipment. When the cartridge is disconnected from the mating equipment, the gas supply port 9A and the gas return port 10A are sealed to maintain the atmosphere inside the cartridge. The gas is subsequently purified by other equipment to remove oxygen, moisture, etc.

[0061] The Z-axis lowers the printing plate after each layer is printed, allowing a new powder layer to be spread and then printed. In this design, the Z-axis frame 11A holds the Z-axis components. The printing plate (also known as the build plate) 12A is where the powder is welded during printing. The printing plate heater 13A contains a heating mechanism for the printing plate 12A (if required) and can also insulate and / or cool the sealing plate 14A. The sealing plate 14A carries the seal 15A, which confines the powder to the Z-axis frame 11A. The Z-axis bottom plate 16A encloses the lower end of the Z-axis frame 11A and has features to accommodate any powder that may slip past the seal 15A. The plunger 17A has an interface that allows the plunger 17A to engage with the Z-axis drive remotely, automatically, and precisely. The plunger seal 18A mates with the bottom plate 16A and further seals the cartridge 1A to prevent powder and / or gas leakage.

[0062] The interface plate 19A contains all the inputs and outputs of the cartridge (compressed air, power, input and output signals, gas, cooling water, etc.). The interface plate 19A is designed to make all these connections when the cartridge is connected to a mating device. The interface can also include a mechanism for electronically identifying each cartridge when it mates with the mating device. The rollers 20A allow the cartridge 1A to roll onto the mating rails of the mating device. The forklift tube 21A allows the cartridge to be picked up and moved by a forklift or other transporter system.

[0063] In another embodiment, the interface plate can be configured to mate with various types or models of printers.

[0064] In one embodiment, drive components (such as motors, actuators, etc.) can be located in the mating station and a linkage can be employed to transfer power from an external drive component to a driven component inside the cartridge. This will reduce the cost and complexity of each cartridge. For example, the powder spreading drive 5A can be coupled to a linkage structure that automatically connects when the cartridge is connected to the printing station / print engine via a gear drive system, a belt system (as shown in 5A), magnetic confinement, electrical, magnetic, inductive, hydraulic, or other similar types of signal or energy transfer. Similarly, the gas and fluid exchange between the cartridge and any compatible mating station can have external powder pumps, fluid pumps, and / or gas pumps that will hook into the cartridge at the interface panel 19A or other convenient locations that will allow the transfer of powder (transfer to the hopper 2A), fluid, or gas without overloading the cartridge with internal service transfer motors / pumps. The internal impellers (for transferring powder and fluid) can be powered by an external motor via the above-mentioned linkage.

[0065] Power coupling through interface panel 19A can be electrical, inductive, or optical, with the latter two allowing for simultaneous power transfer and communication. Additionally, diagnostic information from various sensors built into the cartridge can be obtained via electrical or optical means.

[0066] In one embodiment, cartridge 1A can include an electronic identifier (such as an electronically readable memory 25A) or other electronically readable markings (such as additional text, QR code, or barcode). Memory 25A can provide electronic information about the cartridge, or the cartridge components can be used to identify its brand, model, type, powder type, or any other defining details about the unit, its sub-components, or its intended use. This information can be used to inform the print engine about what material is to be printed, the desired atmosphere (pressure and temperature), or other print-related aspects so that the print engine can adjust as needed to accommodate the print cartridge or sub-assembly. The resulting changes can involve behaviors such as: automatic exchange of internal lens assemblies, adjustment of the z-height / final optical projection of the lens assembly, laser parameter adjustment (such as power per unit area, pulse shape, pulse duration, pulse repetition rate, wavelength, spatial pulse shape, tile size, spatial energy distribution within the tile), modification of data diagnostics, data feedback algorithms, print process feedback algorithms, or algorithm changes on how tiles are laid down during the print process. Electronic information from the electronic memory 25A associated with the print cartridge can be read by the printer, powder removal station, or storage shelf to gather data on how much printing has occurred and other key metrics (such as the number of spreader cycles, z-axis adjustments, temperature cycles, pressure cycles, or other attributes the cartridge has experienced along the way). This information can also be stored in a central database via the print station, one of the subsystems, factory automation system, powder removal station, cartridge storage station, the cartridge itself, or other mating / interface devices.

[0067] Figure 1B An embodiment of an additive manufacturing system 1B including cartridge 2B is illustrated. As shown, cartridge 2B is transported to print station 11B on a customized transport fixture 4B carried by a transporter (here represented by a forklift 3B). The transporter can engage with the cartridge such that all or some of the cartridge's services and functions are operative, or the cartridge can be partially or fully disconnected from services and inoperative while being carried by the transporter. As will be described in more detail later, print engine 11B is a system module that includes a print station and a laser engine station. Cartridge 2B is ready to print when it has been prepared (i.e., filled with new powder, a new print plate installed, all cartridge components inspected, updated, and aligned, filled with the appropriate gas, has a pre-heated print plate, etc.) in another mating device such as a preparation service station (not shown).

[0068] The transporter 3B aligns the transport fixture 4B with the mating guide rail 5B. Once aligned, the capture mechanism 6B pulls the print cartridge 2B into the print station 11B. The print cartridge 2B is aligned and locked in place within the print station 11B. As the cartridge 2B is pulled into place, its interface board (similar to the interface board described with respect to Figure 1A is aligned with the print station interface board 9B. When the cartridge 2B is locked in place, the interface boards fully mate and services (compressed air, power, input and output signals, gases, cooling water, etc.) are provided to the print cartridge 2B. Locking in place may alternatively or additionally involve the use of permanent magnets or electromagnets, pins, clamps, hooks, cables, ramps, air bearings, linear slides, linkages, or robotic end effectors. Additionally, hardware keying can be used as an additional safety measure to prevent improper behavior, such as when reactive metals are loaded into the cartridge and it is necessary to ensure that the atmosphere in the print station is suitable to not cause an explosion. Additional or alternative keying, such as electronic, optical, and software, can be used as an overarching safety measure and to prevent unauthorized use of FRUs independent of the approved station.

[0069] Once mated, the Z-axis piston 7B rises to touch the z-axis plunger (similar to the one described with respect to Figure 1A ). Once the Z-axis piston 7B and the z-axis plunger make contact, the automatic clamp 8B connects the two. The cartridge Z-axis is now fully controllable by the print station 11B. The built-in optical diagnostic device (camera / sensor) and lighting within the cartridge are now powered by the print station 11B, and the diagnostic images / data can be displayed on the virtual window 10B and / or anywhere else the print station is directed to send the images / data.

[0070] When printing is complete, the transporter 3B aligns the transport fixture 4B with the print cartridge 2B. The capture mechanism 6B pushes the print cartridge 2B such that the print cartridge 2B rolls outwards and onto the transport fixture 4B. The print cartridge 2B mates with and locks into place on the transport fixture 4B. The transporter 3B can now deliver the cartridge 2B to another station or another piece of mating equipment. The print station 11B is immediately available such that another print cartridge can be loaded into place and the next print can begin with minimal downtime between prints. Note that this second print cartridge can contain a completely different printable material.

[0071] In this case, the transporter (3B) is a human-driven cassette transporter, but in other embodiments, the transporter can be partially or fully automated. In other cases, the partially or fully automated transporter can be guided by a telepresence camera (remote operator), by an embedded transponder, by simple or complex algorithms (such as artificial intelligence, neural networks, deep learning networks, neuromorphic processing, or other automatic decision-making methods), and assisted by any number of optical or non-optical sensors.

[0072] In other embodiments, the module interface (6B) is the same height as the cassette, and the transporter 3B engages and locks into the cassette 2B without any height adjustment, eliminating the need for "forklift-style" operation on the transporter 3B.

[0073] Figure 1C An embodiment of an additive manufacturing system 1C is illustrated, showing a front view of a print station 11C that holds a print cassette 2C during printing. The cassette 2C has been aligned and is supported by mating rails 3C. The Z-axis piston 4C has risen and is connected to a cassette plunger (similar to that described with respect to Figure 1A A laser beam 5C exits the print station 11C, passes through a cassette top window 6C, and welds powder to a printed part inside the cassette 2C. A safety shield 7C prevents the laser from escaping the print station and protects the operator from accidental contact with the print chamber 2C during printing. The operator can check the print by viewing a camera image displayed on a virtual window 8C. Additionally, any diagnostic data can be displayed on the virtual window 8C, such as images in the visible or non-visible wavelength ranges, optical pyrometric measurements, or information from a laser ultrasonic imaging system (LUIS) or similar high-speed imaging system.

[0074] Figure 1D An example 1D of a front view of a standard cassette interface is illustrated. These interface features 6D can be incorporated into all mating devices such that the cassette can mate with each of the mating devices in the same manner. Cassette mating rails 6D guide and support the cassette. A capture mechanism 2D pulls the cassette into the mating device and pushes the cassette outward back onto a transport fixture (similar to that described with respect to Figure 1Bas described). The dimensions, materials, functions, and locations of these features can be standardized. The standard interface provides maximum flexibility for the customer handling box. Communication with any one of the modules can be accomplished through the interface panel 3D. In some embodiments, communication can be achieved using low-frequency or high-frequency modalities or through a hardware interface. Other methods can include RF, Wi-Fi, inductive, Ethernet, USB, or Bluetooth. High-frequency methods can include fiber optic, LiFi, or free-space optical links. The hardware interface can include SIM, floppy disk, DVD, laser DVD, holographic disk, or volume optical memory structures. The hardware modality can be installed by the operator or have a transfer mechanism that will allow the box to physically transfer one of its instruction storage modes to a similar receiving interface on the module.

[0075] In other embodiments where the box is very large (the size of a shipping container), the box will be very heavy. In these embodiments, the box is fixed, and the station is transported to the box, where Figure 1D the same interface in allows the station to mate with the fixed box.

[0076] Figure 1E FIG. illustrates an exemplary additive manufacturing system 1E that includes a storage station or storage shelf 11E, which shows three boxes 2E that have been installed. A transporter 4E is illustrated transporting a fourth box 3E to the shelf 11E for storage. The shelf 11E has four instances of standard print box interfaces, including supports, mating rails 5E, interface plates 6E, and capture mechanisms 7E. The shelf 11E will have a service station 8E that houses devices for supplying services (compressed air, power, input and output signals, gas, cooling water, etc.) to each box as needed. The service station 8E can be configurable to allow the customer to use the shelf flexibly. The status of each box 2E can be obtained on one or several monitors, which will also serve as virtual windows 9E so that the operator can observe the interior of each box.

[0077] The shelf 11E provides a place for storage cartridges. Unused or new cartridges can be stored here, filled with new powder and a new print plate, ready to be installed in the print engine to start a new print. The shelf 11E can preheat the print plate as needed for the print job assigned to the cartridge and keep the cartridge filled with gas. Additionally, cartridges containing newly completed prints can be stored on the shelf 11E while waiting for post-processing. The prints can be maintained at any temperature, or the temperature can be ramped up or down following a temperature profile. This can allow annealing or heat treatment of the prints to relieve stress or obtain desired mechanical properties. This can simply give the prints time to cool enough to be defluffed. The atmosphere can also be changed, for example, by introducing a new gas or a mixture of gases, to obtain desired mechanical properties. In other system embodiments, empty cartridges can simply be stored on the storage shelf 11E so that the empty cartridges are out of the way. Cartridges can be stored on the shelf 11E in any state, including new and filled with powder, used and depleted of powder, or partially used.

[0078] Diagnostics built into the cartridge can continuously monitor the print status. These built-in diagnostics can include part, powder, and ambient temperature, image diagnostics at multiple wavelengths, and other modalities such as vibration and ultrasonic imaging, as well as LUIS volume mapping of the printed part. For any cartridge contained in the shelf, any diagnostic information (image or data) can be shown on the virtual window 9E. Additionally, information for current and past cartridges can be sent to any other virtual window or any user interface via the control system.

[0079] Figure 1F An example of a print engine 11F with an attached auxiliary print station 2F is illustrated. The print engine 11F can accept a print cartridge 3F. The auxiliary print station 2F can also accept a print cartridge 4F. The auxiliary print station 2F uses the laser energy generated by the print engine 11F to print parts. When the cartridges 3F or 4F are installed in their respective print modules 11F and 2F, the print engine can direct the laser energy to the cartridge 3F or 4F. The processing priority can be set to favor the cartridge 3F such that most of the laser emissions are directed to the cartridge 3F. When the laser energy cannot be sent to the cartridge 3F (e.g., during powder spreading or unloading / loading the print cartridge), the energy can be directed to the cartridge 4F, ensuring maximum use of the print engine 11F laser.

[0080] Figure 1GIllustrates an alternative embodiment of an additive manufacturing system 1G. A plurality of print engines 11G are closely placed together on the shop floor. A service aisle 2G allows a transporter 3G to transport a print cartridge 4G between the print engines and a powder station 5G, a shelf 6G, and any other mating equipment pieces. A facility station 7G can be located on a mezzanine 8G to save floor space. This printer is particularly suitable for this type of multi-unit factory layout due to its low cycle time and fast printing speed. This layout provides cost-effectiveness as mating equipment can be shared among many print stations / engines. In some embodiments, various types of communication between the cartridge, print engine, powder station, and shelf are possible. In other embodiments, identification information on the cartridge can be used to direct the automatic, semi-automatic, or manual positioning of the cartridge at the appropriate print engine, powder, or storage module. The types of communication that can be used include low-frequency and high-frequency methods, including RF, Wi-Fi, inductive, Ethernet, USB, Bluetooth (low-frequency type), fiber optic, LiFi, FSO (high-frequency type). Additionally, this information can be transferred from the cartridge to the mating station using physical media hardware such as SIM, floppy disk, DVD, laser DVD, holographic disk, or volumetric optical media.

[0081] Figure 1H Illustrates an alternative embodiment of an additive manufacturing system 1H. A print chamber 11H has a fixed window 6H positioned at the top of the chamber. A print head 5H can be mounted to an X-Y gantry such that the print head 5H can traverse the entire area of a print plate 2H. This movement is represented by arrow 8H. A laser beam 7H is projected from the print head, passes through the window 6H, and welds powder to a metal part on the print plate 2H. The window must be large enough, roughly as large as the print plate, such that the laser can be directed to the entire area of the print plate. A powder hopper 4H and a Z-axis wall 3H are shown for reference.

[0082] Figure 1I Illustrates an alternative embodiment of an additive manufacturing system 1I. In this embodiment, a print chamber 11I includes a window 6I that is mounted to a bellows 7I such that the window is free to move in the X-Y plane (represented by 10I). After a cartridge is installed in the print engine, the window 6I is attached at position 9I to the print head 5I using a clamp, magnet, kinematic mount, or other suitable attachment mechanism (this can be done manually or automatically). The print head 5I is mounted to an X-Y gantry such that the print head 5 can traverse the entire area of a print plate 2I. This movement is represented by arrow 10I. Since the window 6I and the print head 5I are attached, the window 6I will move with the print head 5I. A laser beam 8I is projected from the print head, passes through the window 6I, and welds powder to a metal part on the print plate 2I. In this embodiment, the window 6I can be significantly smaller than the print plate 2I as the window 6I will be carried around the entire area of the print plate. A powder hopper 4I and a Z-axis wall 3I are shown for reference.

[0083] Figure 1J An alternative embodiment of the additive manufacturing system 1J is illustrated. The printing chamber 11J has a window 6J that is mounted to a bellows 7J such that the window is free to move in the X-Y plane. After the cartridge is installed in the printing station, the window 6J is attached to an auxiliary X-Y gantry 10J at location 9J using a clamp, magnet, kinematic mount, or other suitable attachment mechanism. The auxiliary X-Y gantry 10J is attached to the printing station (alternatively, the auxiliary X-Y gantry can be part of the printing cartridge). The auxiliary X-Y gantry can be much cheaper and lighter than the printhead X-Y gantry because the auxiliary X-Y gantry has a relatively small weight to support and does not have to move as quickly or precisely as the printhead X-Y gantry. The printhead 5J is mounted to the X-Y gantry such that the printhead 5J can traverse the entire area of the printing plate 2J. This movement is represented by arrow 13J. The printing station system controller can direct the auxiliary gantry 10J to move in unison with the printhead 5J. A laser beam 8J is projected from the printhead, passes through the window 6J, and welds powder to the metal part on the printing plate 2J. In this embodiment, the window 6J can be significantly smaller than the printing plate because the window 6J will follow the movement of the printhead over the entire area of the printing plate. A powder hopper 4J and a Z-axis wall 3J are shown for reference.

[0084] Figure 1K An alternative embodiment of the additive manufacturing system 1K is illustrated. This embodiment is similar to the embodiment illustrated with respect to Figure 1I except that the attachment 9K is more flexible and the printhead pushes and moves the window 6K. In this embodiment, a mechanism supports the window 6K against gravity such that the window does not sag.

[0085] Figure 1L An alternative embodiment of the additive manufacturing system 1L is illustrated. This embodiment is the same as the one illustrated with respect to Figure 1HThe illustrated embodiments are similar. The carriage is positioned on the guide rail 8L and is driven past the window 6L. Each pass of the wiper cleans the dirt accumulated on the window surface, which allows the laser energy 7L to pass through the window unobstructed. In some embodiments, the wiper can be a cloth-like material that is dry or soaked in a solvent and then quickly wiped against the inner window of the cartridge. In other embodiments, the wiper can be constructed of a bristle brush with soft bristles that do not harm or scratch the window but are stiff enough to allow any powder to be wiped off. In some embodiments, the wiper can be a gas jet (such as an air knife) for non-contact cleaning. In some embodiments, the wiper can be a gas or liquid sprayer or a combination of such a sprayer and a physical wiper. After cleaning the window, the wiper can be cleaned by a gas jet, wiped on a dedicated or rough surface to remove any powder, or cleaned by a solvent or bath in a separate cleaning area. In some embodiments, the wiper can be replaced when it gets dirty. In some embodiments, the dirty part of the wiper can be moved to expose a new part of the wiper. In some embodiments, the wiper is made of cotton, polyester, wool, carbon fiber strands, Kevlar, fiberglass, aluminized fabric, ceramic fabric, silica fabric, or other suitable materials.

[0086] Figure 1M An alternative embodiment of the additive manufacturing system 1M is illustrated. The print head 5M can be mounted to an X-Y gantry such that the print head 5M can traverse the entire area of the print plate 2M. This movement is indicated by the arrow 8M. The print chamber 11M has a hole 16M positioned at the top of the chamber. The hole can be closed by a sliding door 12M and isolated from the surrounding environment by a seal 13M. The door can be opened or closed by an actuator 14M. The print station 15M has a fixed window 6M that isolates the print station from the surrounding environment.

[0087] Figure 1N The "open" position of an alternative embodiment of the additive manufacturing system 1M is illustrated. The print station 15N inflates a seal 17N against the top of the print chamber to isolate the chamber from the surrounding environment. The door 12N can then be opened by an actuator 14N, causing the hole 16N to open. A laser beam 7N is projected from the print head, passes through the window 6N, and welds the powder to the metal part on the print plate 2N. The window must be large enough, roughly the same size as the print plate, such that the laser can be directed to the entire area of the print plate. In this embodiment, the window 6N is fixed to the print station 15N, making the print chamber 11N less expensive. The powder hopper 4N and the Z-axis wall 3N are shown for reference.

[0088] Figure 1OIllustrated is an additive manufacturing system 1O, which includes a print facility control system connected to various stations of the print facility and a database 2O connection. The control system and the database 2O communicate with a cartridge 3O, a print station 4O, a shelf 5O, a powder removal station 6O, a transporter (cartridge movement system) 7O, and a facility station 8O. Each of these components can provide status updates and perform real-time reconfiguration to optimize facility operation.

[0089] Figure 1PFIG. illustrates an additive manufacturing system 1P, which includes various other possible stations that can be part of the additive manufacturing system 1P. In some embodiments, cartridges are loaded into the stations. Examples of stations are printing stations equipped with cartridges, where energy (laser or electron beam) is delivered from a laser engine (station) into the printing station to enable the printing station to print parts. Generally, the laser engine is only used in combination with the printing station to turn the combination into a printing engine. These stations can be arranged and connected to each other to form a manufacturing system. The manufacturing system can include many stations equipped with cartridges, as well as support stations captured in a frame arrangement. The stations equipped with cartridges and the support stations are coordinated by a control system, and the control system obtains printing instructions from the user to complete a printing order / job. These other functional stations can suppress dirty processes to reduce human exposure when manufacturing 3D parts. As mentioned previously, 3D printing itself is messy, and so are the pre-treatment and post-treatment of cartridges, the post-treatment of powder, and the post-treatment of printed parts. In addition, the cartridge system interface is used to interact with various diagnostic systems. The control system and the database 2P will communicate with the cartridge individually, or when the cartridge is connected to any of the listed stations 40P or when the cartridge is manipulated by a transporter 5P, the control system and the database 2P will communicate with the cartridge. The listed stations are not an all-inclusive list, but do include a printing engine 41P (composed of a printing station 42P and a laser engine 43P), a storage (shelf) station 44P, a facility station 56P, and a powder preparation / de-powdering station 45P. The powder preparation station can be a station for preparing cartridges, which will include removing powder from cartridges that have undergone printing. These two functions (preparing cartridges and powder removal) can be done in one station or two separate stations. In the case of two separate stations, the preparation station can be called "prep", and the other can be called "de-powdering". Other stations can include a surface coating station 46P, a heat treatment station 47P, a CNC / machining station 48P, a surface finishing station 49P, a preparation service station, a deburring station, a powder re-screening station 52P, a powder surface treatment / coating station 53P, a LUIS diagnostic station 54P, other volume and surface diagnostic stations 55P, and other processing stations 56P. The laser engine 43P cooperates and interacts with the printing station 42P (to form the printing engine 41P), cooperates and interacts with the surface coating station 46P, the LUIS diagnostic station 54P, and can interact with the heat treatment station 47P and the surface finishing station 49P.

[0090] The print station 42P, surface coating station 46P, heat treatment station 47P, CNC / machining station 48P, surface finishing station 49P, and deburring station 51P perform post-processing on the printed parts. The surface coating station 46P operates in conjunction with the laser engine 43P on the printed parts to add a functional layer to selected surfaces in the case of drill bits, airfoil surfaces, turbine blades, or medical implants. The heat treatment station 47P in combination with the laser engine 43P can perform surface annealing and hardening, or the heat treatment station 47P can use other conventional methods such as standard heat sources or non-laser sources of directed energy to perform this form of post-processing. The CNC / machining station 48P performs standard subtractive manufacturing on the printed parts to obtain the final geometry and form. The surface finishing station 49P can interact with the laser engine 43P to perform surface smoothing via mass transport / surface tension or laser peening / hardening. The surface finishing station 49P can also be performed by more conventional subtractive methods (which do not require coupling 49P to 43P). The deburring station 51P will use conventional subtractive machining methods to improve the surface finish of the printed parts. The LUIS diagnostic station 54P will be coupled to the laser engine 43P (configured with FRUs dedicated to LUIS) to perform volumetric scans of the printed parts to ensure print accuracy, density, and defect statistics. Additionally, LUIS and other volumetric diagnostics (54P and 55P respectively) can be used in conjunction with the storage station and the laser engine to determine the functionality of the printed parts in conditioned environments such as high or low temperature, high or partial vacuum, or other environmental or operating extremes to ensure that the printed parts can withstand static operating performance requirements.

[0091] The preparation service station 50P is for maintenance cartridges and can be used in combination with the powder station 45P and the facility station 56P. In the preparation station, consumables such as Figure 1A the wiper blade 4A, build plate 12A, and HEPA filter 8A in are replaced in a manner that minimizes human interaction with the dirty environment. Gases and fluids are removed for post-processing via the facility station 56P. Used powder is removed and transferred to the powder re-screening station 52P for powder recovery.

[0092] The powder handling / coating station processes the powder for chemical action or emissivity enhancement, which will depend on the powder / metal used, but can include chemical treatment or oxide treatment to enhance emissivity (e.g., increasing the absorption of copper or steel by surface treatment of the powder), or adding chemical dopants to the powder to obtain special printing parameters.

[0093] Other volumetric diagnostic stations 55P will include, to name just a few examples, x-ray tomography, surface scan imaging, high-resolution surface and temperature recording imaging, where the printed part is manipulated while minimizing processing damage and not exposing people to hazardous metrology methods (as in the case of x-ray tomography).

[0094] Other processing stations will allow customer needs to be met by isolating potentially hazardous processes, tests, or diagnostic processes from workers and / or printed parts.

[0095] Advantageously, the described additive manufacturing system describes a cartridge that encompasses the entire printing chamber and all of its components. The cartridge can be transported between mating devices. The use of cameras and virtual windows eliminates the need for physical windows. In one embodiment, a display screen can allow for remote inspection of the cartridge. Lasers can pass through the top window to perform welding, preheating, heat treatment, or provide other thermal operations on the powder. Lasers can be directed to an auxiliary printing station to utilize laser emissions that would otherwise be wasted and increase manufacturing throughput.

[0096] Other advantages of the described additive manufacturing system are based on the use of an electronically readable memory for the cartridge, such that data can be stored or associated with its intended use. The cartridge design can use standard interfaces to mate the cartridge with mating devices. The electronically readable memory on the cartridge can notify actions to be taken on the printing engine before, during, or after the printing process. The mating devices can read information and / or write information to the electronically readable memory. An operator can access the electronically readable memory with a handheld unit. A storage shelf can service the cartridges and assign information to the electronically readable memory, or be used for heat treating the printed article before removal from the printing plate.

[0097] The described additive manufacturing system protects workers by isolating them from hazardous printer byproduct materials (metal powder, soot, weld slag, inert gas, etc.), where the printer byproduct materials are contained within the printing cartridge. All machine components exposed to the printer byproduct materials are removed with the cartridge, and the cartridge can be opened within a dedicated powder handling station. This arrangement limits the opportunity for printer byproduct materials to escape into the factory environment. When the cartridge is installed in the powder station or preparation station, workers have full access through glove ports to service all cartridge components, so workers never have to don special protective gear to service the cartridge. Alternatively, the powder station or preparation station can be installed in a clean room, and workers will wear respirators and protective clothing to service the cartridge. This scenario will isolate all of the dirt from the clean room, eliminating exposure in the rest of the factory.

[0098] Another advantage of the described additive manufacturing system is that it increases printer uptime by reducing the idle time between prints. When a print is complete, the operator can remove the print cartridge, immediately install a new cartridge, and start a new print. The idle time between prints is reduced from hours to minutes. The print cartridge can be cleaned, maintained, and loaded with new powder and a new print plate offline at a preparation station. This work is done in a sealed environment so that the print chamber and powder are never exposed to air, high humidity, or factory contaminants. New cartridges can be prepared in advance to meet the customer's production schedule. New cartridges are placed on storage shelves where they can be preheated, cooled, pressurized, or depressurized in any desired atmosphere. When the space on the printer becomes available, any new cartridge is inserted and printing begins immediately because there is no waiting time to preheat the cartridge or purge the atmospheric gases.

[0099] Another advantage of the described additive manufacturing system is that it allows the printer to create prints in any material (metals such as steel, aluminum, inconel, titanium, wood, glass, or ceramics), and then, once the print is complete, print any other material with little or no downtime for maintenance between prints. Since no powder remains in the printer, there is no need to clean the printer before it can print from a cartridge filled with a different material. This not only saves time but also provides the customer with maximum flexibility because the printer does not have to be dedicated to handling only one material.

[0100] Another advantage of the described additive manufacturing system is that the cartridge and / or station can be slightly modified or highly modified to suit the customer's requirements. For example, the cartridge can be designed with a much smaller surface area print plate or a print plate of a different shape (i.e., round instead of square). For example, this can allow the customer to print small volumes of very expensive materials (e.g., gold). Such a small-capacity cartridge can be designed to interface with a variety of print stations to maximize the flexibility of the print materials available to the customer.

[0101] Another advantage of the described additive manufacturing system is that it allows high-temperature treatment of the prints (e.g., heat treatment, annealing, controlled cooling) without removing the prints from the controlled environment in which they were printed (i.e., the print cartridge heats and cools and controls the atmosphere). The cartridge can be sent to a storage shelf and stored at any temperature in any gas environment according to the customer's requirements. The prints are not exposed to atmospheric air or allowed to cool, so the customer has excellent control to influence the properties of the material. This can also mitigate the problem of print plate warping due to thermal stress.

[0102] Another advantage of the described additive manufacturing system is that it allows printing to be created in any of a plurality of print cartridges that can be simultaneously installed in one or more auxiliary print stations. This will further reduce the total print time by utilizing laser energy that would otherwise be wasted. The additive manufacturing system will also provide customers with the flexibility to schedule prints and will also increase machine utilization.

[0103] Another advantage of the described additive manufacturing system is that the features in the cartridge and mating equipment can be implemented as standard or optional features on additive manufacturing systems manufactured by other equipment manufacturers. The technology is provided as a subsystem to be incorporated into additive manufacturing equipment using laser powder bed fusion or other 3D printing methods. Any additive manufacturing system that utilizes the cartridge / station scheme will enjoy the benefits of this scheme. The cartridge and station can be slightly modified or highly modified to suit the particular needs of the manufacturer or customer.

[0104] Various alternatives or enhancements to the various components of the described additive manufacturing system are envisioned. For example:

[0105] Regarding Figure 1H 、 Figure 1I and Figure 1J The bellows of the illustrated embodiment can be replaced or supplemented with a series of sliding plates (cables, etc.) that will support the window such that the window is allowed to move freely in the X and Y axes but is prevented from sagging in the Z axis. If a particular print requires less powder, the user can partially fill the powder hopper.

[0106] The blade-type spreader can be replaced with a roller or an electrostatic spreader.

[0107] The powder spreader drive can be remotely mounted and driven by a suitable interface that transfers power to the mechanism (e.g., a flexible shaft). The powder spreader can be actuated by various types of actuators including gear drives. In some embodiments, the powder spreader can be a removable and upgradable subsystem of the cartridge.

[0108] HEPA filters can be installed on the print cartridge, on the mating equipment, or on both the mating equipment and the print cartridge. The HEPA filter can also have a pre-filter, such as a cyclone separator or a screen, to handle large amounts of soot.

[0109] Multiple gas supply ports and gas return ports can be supported, and the gas supply ports and gas return ports can be physically located at different positions on the cartridge to prevent different types of powders from mixing.

[0110] In some embodiments, a camera can capture video and still images to provide a virtual window. The camera and lights can illuminate and image with a variety of light wavelengths (e.g., IR, visible light, or UV). The camera can be an array of several cameras, and the array of cameras can record static and / or video images from many different angles at one or many light wavelengths. The lights can be one light or an array of many lights, and the lights illuminate the cartridge from many angles and at many different wavelengths. The virtual window can be viewed from anywhere, so the images can be sent to a remote viewing location. The virtual window monitor can be located on the cartridge itself, on the front of the printing station, or as a display on a monitor mounted on an industrial monitor / keyboard arm. In some embodiments, the cartridge can also have a physical window or port to allow direct viewing through the eye or viewing through an external camera or other sensor.

[0111] Various types of cartridge transportation are envisioned. In some embodiments, the rollers can be replaced with telescoping tubes, pick and place robots, overhead lifters, guide rails, or conveyors. The forklift tubes can be replaced with carts, automated equipment (such as conveyor belts), guide rails, robotic equipment (such as bottom lift stockers), robotic tugs, or robotic forklifts. Using an overhead gantry / crane mechanism; (manual or fully automated) carts or wagons rolling on the floor (arriving at a manual or automatic rail system (magnetic levitation, air bearings) that can be wheeled or non-wheeled), robotic manipulators, conformal body power suits are alternative embodiments.

[0112] The plunger / z-axis piston can mate with a zero-point fixture or some other kind of automatic fixture.

[0113] The safety shield can be part of the cartridge, attached to the print engine, or some combination of both. The material of the safety shield will be opaque to the laser. When the system is operating, the outer surface of the safety shield will need to feel cool.

[0114] To prevent cross - contamination between powder types, the interface plate can use different configurations or be positioned in different areas (e.g., shifted left or right, or up or down), depending on the type of gas or powder used in the cartridge. For example, the recycle gas port of a cartridge containing steel powder can be on the left, while the recycle gas port of a cartridge containing aluminum powder can be on the right. The ports for different materials will not align, so the operator will not incorrectly insert the wrong cartridge into the gas recycler. In some embodiments, multiple gas recyclers in each print engine can support printing different materials. For example, a drive gas recycler impeller using an external motor can switch between two sets of impellers. This allows using only one expensive motor to drive two relatively inexpensive impellers in separate gas conduits for separate materials. In some embodiments, the gas recycle module (gas cartridge) can be inserted into or removed from the print engine as needed for the material to be processed. In some embodiments, a gas recycle device including a filter can be directly mounted on the print engine. In other embodiments, the filter and "material - dependent" devices are mounted in the cartridge unit itself, so that any cross - contamination is completely avoided when different cartridges containing different materials are installed.

[0115] Storage shelves can be made in many different sizes to hold one or many cartridges. The cartridges can be programmed at the storage shelf and automatically set up for the jobs to be run according to a predetermined job schedule. The electronic memory held within each cartridge can interface with a robotic manipulation system, crane, track, transport equipment, or communicate with a transporter and / or its operator or system to tell it which print station / engine to connect to in the production setup. The cartridges can be battery - powered, so that sensor or information - providing functions are possible when disassembled.

[0116] A print engine can have more than one auxiliary print station (i.e., 1 - N) attached to the print engine, where N can be 1, 10, 100, or 1000, or between them, or more.

[0117] While printing simultaneously or sequentially, the print cartridges can be filled with the same or different materials.

[0118] Before patterning, the laser can be split between print stations, where each print station has its own light valve or patterning device. In other embodiments, the laser can be split in the chamber after patterning, where the first chamber gets the positive (priority) image and subsequent chambers get the remaining (negative) images.

[0119] The energy flux directed to each cartridge can be the same or can vary based on the material type.

[0120] In one embodiment, the use of print cartridges and / or print engines can be prioritized, where the use of each print cartridge or print engine can be prioritized before or during printing. For example, a cartridge with a priority can remain static or can change based on an input (i.e., an input from a user such as a change in job priority or due to print completion, print error, or other external expectations). The priority of any cartridge can be raised or lowered. For example, if there are two cartridges and the highest priority cartridge becomes idle (due to user intervention, subsystem processes such as spreading, image loading, or the like, errors, etc.), the priority will then change to the previously lower priority cartridge, thus maximizing the overall print throughput. This change is true for any number of cartridges greater than one. As another example, a customer can prioritize printing high-temperature prints at the main print station where the main cartridge is inserted and assign a lower priority to room-temperature, less demanding prints at the auxiliary print station. Low-temperature printing can be done at a much slower rate without sacrificing print quality or without necessarily keeping the auxiliary chamber hot.

[0121] Each print cartridge in each print station can print the same or different print files. Each print can be started and stopped while the prints in the auxiliary print cartridges continue to print. During a printing operation with more than one chamber, a print cartridge can be installed in or removed from a print station without interrupting the printing process in the chambers that are not removed.

[0122] Figure 2 FIG. illustrates a process flow 200 for operating a cartridge-based additive manufacturing system. In step 202, a new or reused cartridge is positioned in the print engine. In step 204, laser energy is directed into the cartridge to build a 3D part. In step 204, laser energy is directed into the cartridge to melt, sinter, fuse, or otherwise alter a powder layer. In step 206, additional powder is positioned and subjected to laser energy, where the process is repetitively added to build each layer and produce a 3D printed structure. In step 208, the cartridge can be removed and maintained at a separate powder handling station. The maintained cartridge or a new cartridge can be positioned in the print engine for manufacturing additional or new 3D prints.

[0123] In connection with Figure 3 In another illustrated embodiment, an additive manufacturing system such as that illustrated in the process flow in connection with Figures 1A - 1H and Figure 2 can be represented by various modules that form an additive manufacturing method and system 300. As Figure 3As can be seen, the laser source and amplifier 312 can be configured as a continuous or pulsed laser. In other embodiments, the laser source includes a pulsed electrical signal source, such as an arbitrary waveform generator or an equivalent that acts on a continuous laser source (such as a laser diode). In some embodiments, this can also be achieved via a fiber laser or a laser source emitting through a fiber, which is then modulated by an acousto-optic or electro-optic modulator. In some embodiments, a high repetition rate pulsed source using a Pockels cell can be used to create a pulse sequence of any length.

[0124] Possible laser types include, but are not limited to: gas lasers, chemical lasers, dye lasers, metal vapor lasers, solid-state lasers (such as fiber), semiconductor (such as diode) lasers, free electron lasers, gas dynamic lasers, "nickel-like" samarium lasers, Raman lasers, or nuclear pumped lasers.

[0125] Gas lasers can include lasers such as helium-neon lasers, argon lasers, krypton lasers, xenon ion lasers, nitrogen lasers, carbon dioxide lasers, carbon monoxide lasers, or excimer lasers.

[0126] Chemical lasers can include lasers such as hydrogen fluoride lasers, deuterium fluoride lasers, COIL (chemical oxygen iodine laser), or Agil (all-gas-phase iodine laser).

[0127] Metal vapor lasers can include lasers such as helium-cadmium (HeCd) metal vapor lasers, helium-mercury (HeHg) metal vapor lasers, helium-selenium (HeSe) metal vapor lasers, helium-silver (HeAg) metal vapor lasers, strontium vapor lasers, neon-copper (NeCu) metal vapor lasers, copper vapor lasers, gold vapor lasers, or manganese (Mn / MnCl 2 ) vapor lasers. Rubidium or other alkali metal vapor lasers can also be used. Solid-state lasers can include lasers such as ruby lasers, Nd:YAG lasers, NdCrYAG lasers, Er:YAG lasers, neodymium YLF (Nd:YLF) solid-state lasers, neodymium-doped yttrium orthovanadate (Nd:YVO4) lasers, neodymium-doped yttrium calcium oxyborate Nd:YCa 4 O(BO 3 ) 3 or simply referred to as Nd:YCOB, neodymium glass (Nd:Glass) lasers, titanium sapphire (Ti:sapphire) lasers, thulium YAG (Tm:YAG) lasers, ytterbium YAG (Yb:YAG) lasers, ytterbium:2O 3(Glass or ceramic) lasers, ytterbium-doped glass lasers (rods, plates / chips, and optical fibers), holmium YAG (Ho:YAG) lasers, chromium zinc selenide (Cr:ZnSe) lasers, cerium-doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), promethium-147 phosphate glass (147Pm+3:Glass) solid-state lasers, chromium-doped beryllium aluminum oxide (alexandrite) lasers, erbium-doped and erbium-ytterbium co-doped glass lasers, uranium(III)-doped calcium fluoride (U:CaF 2 ) solid-state lasers, samarium(II)-doped calcium fluoride (Sm:CaF2) lasers, or F-Center lasers.

[0128] Semiconductor lasers may include laser medium types such as: GaN, InGaN, AlGaInP, AlGaAs, InGaAsP, GaInP, InGaAs, InGaAsO, GaInAsSb, lead salts, vertical cavity surface emitting lasers (VCSELs), quantum cascade lasers, hybrid silicon lasers, or combinations thereof.

[0129] As Figure 3As illustrated, additive manufacturing system 300 uses a laser that can provide one-dimensional or two-dimensional directed energy as part of energy patterning system 310. In some embodiments, one-dimensional patterning can be directed as a linear or curved strip, grating line, helix, or any other suitable form. Two-dimensional patterning can include discrete or overlapping tiles, or an image with varying laser intensity. Two-dimensional image patterns with non-square boundaries can be used, overlapping or interpenetrating images can be used, and images can be provided by two or more energy patterning systems. Energy patterning system 310 uses a laser source and amplifier 312 to direct one or more continuous or intermittent energy beams toward beam shaping optics 314. After shaping, if desired, the beam is patterned by energy patterning unit 316, and typically some energy is directed to waste energy processing unit 318. The patterned energy is relayed by image repeater 320 toward article processing unit 340, and in one embodiment, as a two-dimensional image 322 focused near bed 346. Article processing unit 340 can include a cartridge such as those discussed previously. Article processing unit 340 has a plate or bed 346 (with walls 348), which together form a sealed cartridge chamber that houses material 344 (such as metal powder) dispensed by powder hopper or other material dispenser 342. The patterned energy directed by image repeater 320 can melt, fuse, sinter, amalgamate, change crystal structure, affect stress pattern, or otherwise chemically or physically alter the dispensed and distributed material 344 to form a structure with desired properties. Control processor 350 can be connected to various sensors, actuators, heating or cooling systems, monitors, and controllers to coordinate the operation of laser source and amplifier 312, beam shaping optics 314, laser patterning unit 316, and image repeater 320, as well as any other components of system 300. As will be understood, the connections can be wired or wireless, continuous or intermittent, and include the ability for feedback (e.g., heating can be adjusted in response to sensed temperature).

[0130] In some embodiments, the beam shaping optical device 314 may include a variety of imaging optical devices to combine, focus, diverge, reflect, refract, homogenize one or more laser beams received from the laser source and amplifier 312, adjust the intensity of one or more laser beams received from the laser source and amplifier 312, adjust the frequency of one or more laser beams received from the laser source and amplifier 312, or otherwise shape one or more laser beams received from the laser source and amplifier 312 and direct the one or more laser beams toward the laser patterning unit 316. In one embodiment, a wavelength selective mirror (e.g., a dichroic mirror) or a diffractive element may be used to combine multiple beams, each beam having a different optical wavelength. In other embodiments, a multi-faceted mirror, a microlens, and refractive or diffractive optical elements may be used to homogenize or combine multiple beams.

[0131] The laser patterning unit 316 may include static or dynamic energy patterning elements. For example, the laser beam may be blocked by a mask having fixed or movable elements. To increase the flexibility and simplicity of image patterning, pixel addressable masking, image generation, or transmission may be used. In some embodiments, the laser patterning unit includes an addressable light valve that, alone or in combination with other patterning mechanisms, provides patterning. The light valve may be transmissive, reflective, or use a combination of transmissive and reflective elements. Electrical addressing or optical addressing may be used to dynamically change the pattern. In one embodiment, a transmissive optically addressed light valve is used to rotate the polarization of light passing through the valve, where the optically addressed pixels form a pattern defined by an optical projection source. In another embodiment, a reflective optically addressed light valve includes a write beam for changing the polarization of a read beam. In certain embodiments, non-optically addressed light valves may be used. These may include, but are not limited to, electrically addressable pixel elements, movable mirrors or micromirror systems, piezoelectric or microactuated optical systems, fixed or movable masks or shields, or any other conventional system capable of providing high-intensity light patterning.

[0132] The waste energy handling unit 318 is used to disperse, redirect, or utilize the energy that is not patterned and passes through the image repeater 320. In one embodiment, the waste energy handling unit 318 may include passive or active cooling elements that remove heat from both the laser source and amplifier 312 and the laser patterning unit 316. In other embodiments, the waste energy handling unit may include a "beam dump" to absorb any beam energy not used in defining the laser pattern and convert it to heat. In still other embodiments, beam shaping optics 314 may be used to recycle the waste laser beam energy. Alternatively or additionally, the waste beam energy may be directed to the article handling unit 340 for heating or further patterning. In certain embodiments, the waste beam energy may be directed to an additional energy patterning system or article handling unit.

[0133] In one embodiment, a "switchyard" - type optical system may be used. The switchyard system is adapted to reduce light waste in an additive manufacturing system due to unwanted light discarded due to the pattern to be printed. The switchyard involves the redirection of a complex pattern from where it is generated (in this case, where a spatial pattern is imparted to a plane of a structured or unstructured beam) to where it is delivered through a series of switching points. Each switching point may optionally change the spatial distribution of the incident beam. The switchyard optical system may be used in, for example but not limited to, laser - based additive manufacturing techniques where a mask is applied to light. Advantageously, in various embodiments in accordance with the present disclosure, the discarded energy may be recovered in a homogenized form or as patterned light for maintaining high power efficiency or high productivity. Additionally, the discarded energy may be recovered and reused to increase the strength of more difficult - to - print materials.

[0134] The image repeater 320 can receive the patterned image (one - dimensional or two - dimensional) from the laser patterning unit 316 directly or through a switch station and direct it to the article handling unit 340. In a manner similar to the beam - shaping optics 314, the image repeater 320 can include optics for combining, focusing, diverging, reflecting, refracting the patterned light, adjusting the intensity of the patterned light, adjusting the frequency of the patterned light, or otherwise shaping and guiding the patterned light. Movable mirrors, prisms, diffractive optical elements, or solid - state optical systems that do not require substantial physical movement can be used to guide the patterned light. One of the plurality of lens assemblies can be configured to provide incident light with a magnification ratio, where the lens assembly has both a first set of optical lenses and a second set of optical lenses, and the second set of optical lenses can be exchanged from the lens assembly. The rotation of one or more sets of mirrors mounted on a compensation gantry and a final mirror mounted on a build platform gantry can be used to direct the incident light from a precursor mirror to a desired location. The translational movement of the compensation gantry and the build platform gantry can also ensure that the distance between the incident light and the precursor mirror and the article handling unit 340 is substantially equal to the image distance. In effect, this enables the beam delivery size and intensity for different materials to vary rapidly over the positions in the build area while ensuring high availability of the system.

[0135] A material dispenser 342 (e.g., a powder hopper) in the article handling unit 340 (e.g., a cartridge) can dispense materials, remove materials, mix materials, provide a grading or variation in material type or particle size, or adjust the layer thickness of the material. The materials can include metals, ceramics, glasses, polymer powders, other fusible materials capable of undergoing a thermally - induced phase change from solid to liquid and back to solid, or combinations thereof. The materials can also include composites of fusible and non - fusible materials, where one or both components can be selectively targeted by the imaging relay system to melt the fusible component while leaving the non - fusible material intact or subjecting the non - fusible material to evaporation / destruction / combustion or other destruction processes. In certain embodiments, slurries, sprays, coatings, wires, strips, or sheets of the material can be used. Unwanted materials can be removed for disposal or recycling by using blowers, vacuum systems, sweeping, vibrating, shaking, tilting, or inverting the bed 346.

[0136] In addition to the material handling components, the article handling unit 340 can include components for holding and supporting the 3D structure, mechanisms for heating or cooling the chamber, auxiliary optics or support optics, and sensors and control mechanisms for monitoring or regulating the material or environmental conditions. The article handling unit can support a vacuum or inert gas atmosphere, in whole or in part, to reduce unwanted chemical interactions and mitigate the risk of fire or explosion (especially for reactive metals). In some embodiments, various pure gases or mixtures of other atmospheres can be used, including those containing Ar, He, Ne, Kr, Xe, CO2, N2, O2, SF6, CH4, CO, N2O, C2H2, C2H4, C2H6, C3H6, C3H8, i-C4H10, C4H10, 1-C4H8, cic-2, C4H7, 1,3-C4H6, 1,2-C4H6, C5H12, n-C5H12, i-C5H12, n-C6H14, C2H3Cl, C7H16, C8H18, C10H22, C11H24, C12H26, C13H28, C14H30, C15H32, C16H34, C6H6, C6H5-CH3, C8H10, C2H5OH, CH3OH, iC4H8. In some embodiments, refrigerants or large inert molecules (including but not limited to sulfur hexafluoride) can be used. An enclosure atmospheric composition having at least about 1% He by volume (or number density) and a selected percentage of inert / non-reactive gases can be used.

[0137] In certain embodiments, multiple article handling units, cartridges, or build chambers (each having a build platform that houses a powder bed) can be used in combination with multiple optomechanical assemblies that are arranged to receive one or more incident energy beams and direct them into the cartridges. The multiple cartridges allow one or more print jobs to be printed simultaneously.

[0138] In another embodiment, one or more article handling units, cartridges, or build chambers can have a cartridge held at a fixed height while the optics are vertically movable. The distance between the final optics of the lens assembly and the top surface of the powder bed can be managed to be substantially constant by indexing the final optics upward by a distance equal to the powder layer thickness while holding the build platform at a fixed height. Advantageously, it can be easier to fabricate large and heavy objects compared to a vertically movable build platform because precise micron-scale movement of the changing mass of the build platform is not required. Generally, build chambers intended for metal powders with a volume greater than about 0.1 - 0.2 cubic meters (i.e., greater than 100 - 200 liters or heavier than 500 - 1,000 kg) will benefit most from holding the build platform at a fixed height.

[0139] In one embodiment, a portion of the powder bed layer in the cartridge can be selectively melted or fused to form one or more temporary walls from the melted portion of the powder bed layer to accommodate another portion of the powder bed layer on the build platform. In selected embodiments, fluid channels can be formed in one or more first walls to enable improved thermal management.

[0140] In some embodiments, the additive manufacturing system can include an article handling unit or cartridge that supports a powder bed that can be tilted, inverted, and shaken to substantially separate the powder bed from the build platform in the hopper. The powder material forming the powder bed can be collected in the hopper for reuse in later printing operations. The powder collection process can be automated, and a vacuum system or gas injection system can also be used to assist in powder removal and evacuation.

[0141] In some embodiments, the additive manufacturing system can be configured to easily handle parts that are longer than the available build chamber or cartridge. A continuous (long) part can sequentially advance from a first region to a second region in a longitudinal direction. In the first region, selected particles of the particulate material can be consolidated. In the second region, the unconsolidated particles of the particulate material can be removed. The first portion of the continuous part can advance from the second region to a third region, while the last portion of the continuous part is formed within the first region, and the first portion remains in the same position in the lateral and transverse directions as the position occupied by the first portion within the first and second regions. In effect, additive manufacturing and scavenging (e.g., separation and / or reuse of unused or unconsolidated granular material) can occur in parallel (i.e., simultaneously) at different locations or regions on the part conveyor without stopping for removal of the granular material and / or the part.

[0142] In another embodiment, additive manufacturing capabilities can be enhanced by using an enclosure that limits gas mass exchange between the interior and exterior of the enclosure. An air lock provides an interface between the interior and the exterior; wherein the interior has a plurality of additive manufacturing chambers, including a chamber that supports powder bed fusion. A gas management system maintains the gaseous oxygen within the interior at or below a limiting oxygen concentration, thereby increasing the types of powders that can be used and the flexibility of processing in the system.

[0143] In another manufacturing embodiment, capacity can be increased by housing an article handling unit, a chamber, or a build chamber within an enclosure, where the build chamber is capable of creating parts weighing 2,000 kilograms or more. A gas management system can maintain gaseous oxygen within the enclosure at a concentration below atmospheric levels. In some embodiments, a wheeled vehicle can transport parts from inside the enclosure through an airlock, which serves as a buffer between the gaseous environment inside the enclosure and the gaseous environment outside the enclosure, and to a location outside both the enclosure and the airlock.

[0144] Other manufacturing embodiments relate to the in-process collection and characterization of powder samples from a powder bed. An ingestion system is used for the collection and characterization of powder samples during the process. The collection can be performed periodically, and the results of the characterization lead to adjustments to the powder bed fusion process. The ingestion system can optionally be used for one or more of auditing, process adjustment, or actions such as modifying printer parameters or verifying the proper use of licensed powder materials.

[0145] Another improvement to the additive manufacturing process is described, which can be provided by using a manipulator device such as a crane, a lifting gantry, a robotic arm, or similar device that allows manipulation of parts that are difficult or impossible for a human to move. The manipulator device can grip various permanent or temporary additive manufacturing manipulation points on the part to enable repositioning or manipulation of the part.

[0146] A control processor 350 can be connected to control any of the components of the additive manufacturing system 300 described herein, including lasers, laser amplifiers, optics, thermal controls, build chambers, and manipulator devices. The control processor 350 can be connected to various sensors, actuators, heating or cooling systems, monitors, and controllers to coordinate operations. A wide range of sensors, including imagers, light intensity monitors, thermal sensors, pressure sensors, or gas sensors, can be used to provide information for use in control or monitoring. The control processor can be a single central controller, or alternatively, can include one or more independent control systems. The controller processor 350 is provided with an interface that allows input of manufacturing instructions. The use of a wide range of sensors allows for various feedback control mechanisms to improve quality, manufacturing throughput, and energy efficiency.

[0147] Figure 4An embodiment of the operation of a manufacturing system suitable for additive or subtractive manufacturing is illustrated. In this embodiment, flowchart 400 illustrates an embodiment of a manufacturing process supported by the described optical and mechanical components. In step 402, the material is positioned in a cartridge, bed, chamber, or other suitable support. The material can be a metal sheet that is laser cut using subtractive manufacturing techniques, or a powder that can be melted, fused, sintered, induced to change crystal structure, have an affected stress distribution pattern, or otherwise chemically or physically altered to form a structure with desired properties by additive manufacturing techniques.

[0148] In step 404, unpatterned laser energy is emitted by one or more energy emitters, including but not limited to solid-state or semiconductor lasers, and then amplified by one or more laser amplifiers. In step 406, the unpatterned laser energy is shaped and modified (e.g., intensity modulation or focusing). In step 408, the unpatterned laser energy is patterned, and the energy that is not part of the pattern is processed in step 410 (this can include conversion to waste heat, recovery as patterned or unpatterned energy, or waste heat generated by cooling the laser amplifier in step 404). In step 412, the patterned energy, now forming a one- or two-dimensional image, is relayed towards the material. In step 414, the image is applied to the material, either for subtractive processing or to additively build a part of a 3D structure. For additive manufacturing, these steps can be repeated (loop 418) until the image (or different subsequent images) has been applied to all necessary areas of the top layer of the material. When the energy application to the top layer of the material is complete, a new layer can be applied (loop 416) to continue building the 3D structure. These process loops continue until the 3D structure is complete, at which point the remaining excess material can be removed or recycled.

[0149] Many modifications and other embodiments of the invention will come to mind to those skilled in the art who benefit from the teachings presented in the foregoing description and the related drawings. Therefore, it is to be understood that the invention is not limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims. It is also to be understood that other embodiments of the invention can be practiced without elements / steps specifically disclosed herein.

Claims

1. A cartridge for an additive manufacturing system, the cartridge being attachable to a print station, the cartridge comprising: A sealable chamber having a powder bed in the X-Y plane; A powder hopper positioned within the sealable chamber; A powder spreader positioned within the sealable chamber for dispensing powder from the powder hopper onto the powder bed; and A Z-axis component, the Z-axis component comprising: -- A print plate that supports the powder bed; and -- A plunger that is driven along the Z-axis by a Z-axis piston of the print station to lower the print plate after printing each layer at the powder bed; wherein the print station includes an automatic fixture for connecting the plunger of the cartridge to the Z-axis piston of the print station.

2. The cartridge for an additive manufacturing system according to claim 1, further comprising a laser-transparent window positioned to allow an external camera to focus on the powder bed within the sealable chamber.

3. The cartridge for an additive manufacturing system according to claim 1, wherein the sealable chamber supports a camera to focus on the powder bed within the sealable chamber.

4. The cartridge for an additive manufacturing system according to claim 2, further comprising a wiping blade mounted within the sealable chamber to clean the laser-transparent window.

5. The cartridge for an additive manufacturing system according to claim 2, further comprising a bellows attached to the sealable chamber to hold the laser-transparent window.

6. The cartridge for an additive manufacturing system according to claim 1, wherein the cartridge further comprises an electronic memory attached to the cartridge and configured to store electronic information to identify the cartridge and control the operation of the print station.

7. The cartridge for an additive manufacturing system according to claim 1, wherein the Z-axis component further comprises a seal to confine the powder to a Z-axis frame for holding the Z-axis component.

8. A cartridge for an additive manufacturing system, the cartridge being attachable to a print station, the cartridge comprising: A sealable chamber having a powder bed and a laser-transparent window in the X-Y plane; A powder hopper positioned within the sealable chamber; A powder spreader for dispensing powder from the powder hopper onto the powder bed; A bellows attached to the sealable chamber to hold the laser-transparent window; and A Z-axis component, the Z-axis component comprising: -- A print plate that supports the powder bed; and -- A plunger that is driven along the Z-axis by a Z-axis piston of the print station to lower the print plate after printing each layer at the powder bed; wherein the print station includes an automatic fixture for connecting the plunger to the Z-axis piston of the print station.

9. The cartridge for an additive manufacturing system according to claim 8, wherein the laser-transparent window is positioned to allow an external camera to focus on the powder bed within the sealable chamber.

10. The cartridge for an additive manufacturing system according to claim 8, wherein the sealable chamber supports a camera to focus on the powder bed within the sealable chamber.

11. The cartridge for an additive manufacturing system according to claim 8 further includes a wiper blade, and the wiper blade is installed in the sealable chamber to clean the laser transparent window.

12. A cartridge for an additive manufacturing system, the cartridge being attachable to a printing station, the cartridge comprising: a sealable chamber having a powder bed and a laser transparent window in the X-Y plane; a powder hopper positioned within the sealable chamber; a powder spreader positioned within the sealable chamber for dispensing powder from the powder hopper onto the powder bed; a wiper mechanism configured to clean the interior of the laser transparent window; and a Z-axis component, the Z-axis component including: -- a printing plate that supports the powder bed; and -- a plunger that is driven along the Z-axis by a Z-axis piston of the printing station to lower the printing plate after each layer is printed at the powder bed; wherein the printing station includes an automatic fixture for connecting the plunger of the cartridge to the Z-axis piston of the printing station.

13. The cartridge for an additive manufacturing system according to claim 12, wherein the laser transparent window is positioned to allow an external camera to focus on the powder bed within the sealable chamber.

14. The cartridge for an additive manufacturing system according to claim 12, wherein the sealable chamber supports a camera to focus on the powder bed within the sealable chamber.

15. The cartridge for an additive manufacturing system according to claim 12 further includes a bellows attached to the sealable chamber to hold the laser transparent window.

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