Additive manufacturing systems and methods

Abstract

The present disclosure relates to additive manufacturing systems and methods. An additive manufacturing system including a two-dimensional energy patterning system for imaging a powder bed is disclosed. Improved structure formation, part creation and manipulation, use of multiple additive manufacturing systems, and high-throughput manufacturing methods suitable for automated or semi-automated factories are also disclosed.

Description

[0001] This application is a divisional application of an application filed on October 27, 2016, with application number 201680067938.2 and invention name “Additive manufacturing system and method”.

[0002] Cross-references to related patent applications

[0003] This disclosure is part of a non-provisional patent application claiming the benefit of priority of:

[0004] U.S. Patent Application No. 62 / 248,758, filed October 30, 2015,

[0005] U.S. Patent Application No. 62 / 248,765, filed October 30, 2015,

[0006] U.S. Patent Application No. 62 / 248,770, filed October 30, 2015,

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[0016] U.S. Patent Application No. 62 / 248,780, filed October 30, 2015,

[0017] U.S. Patent Application No. 62 / 248,787, filed October 30, 2015,

[0018] U.S. Patent Application No. 62 / 248,795, filed October 30, 2015,

[0019] U.S. Patent Application No. 62 / 248,821, filed October 30, 2015,

[0020] U.S. Patent Application No. 62 / 248,829, filed October 30, 2015,

[0021] U.S. Patent Application No. 62 / 248,833, filed October 30, 2015,

[0022] U.S. Patent Application No. 62 / 248,835, filed October 30, 2015,

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[0025] U.S. Patent Application No. 62 / 248,847, filed October 30, 2015, and

[0026] U.S. Patent Application No. 62 / 248,848, filed on October 30, 2015, which is incorporated by reference in its entirety. Technical Field

[0027] The present disclosure generally relates to systems and methods for additive manufacturing. In one embodiment, powder bed fusion manufacturing with two-dimensional energy patterning and energy beam reuse is described. background

[0028] 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) typically involves building a part through the sequential, layer-by-layer addition of material. Starting with a 3D computer model, an additive manufacturing system can be used to create complex parts from a wide variety of materials.

[0029] An AM technique called powder bed fusion (PBF) uses one or more focused energy sources, such as a laser or electron beam, to draw patterns in a thin layer of powder by melting the powder and bonding it to the layer below. The powder can be plastic, metal, or ceramic. This technique is highly precise and can typically achieve feature sizes as small as 150-300 microns. However, manufacturers of powder bed fusion AM machines struggle to create machines that can produce more than 1kg / hr of printed material. Because this powder-to-solid conversion rate is slow, machine sizes are relatively small due to the length of time required to print larger parts. Today's largest machines typically have a printable part volume of less than 64L (40cm) 3 Although these printers are capable of printing parts of almost arbitrary geometry, due to high machine costs and low powder conversion rates, the amortized costs of the machines end up being very high, resulting in expensive parts.

[0030] Unfortunately, increasing part size or reducing manufacturing costs by simply scaling up the machine is not an acceptable solution. As a minimum, to melt a given volume of material, the laser must provide enough energy to bring it to melting temperature and provide the phase change energy required for melting. If no heat is dissipated in the process, there is a linear scaling between the laser energy deposited over time (laser power) and material productivity. If powder bed fusion additive manufacturing machine manufacturers want to increase material productivity, they must increase laser power. Unfortunately, increases in laser power are proportional to increases in the cost of the laser, and increases in scale significantly increase the cost of today's already expensive machines.

[0031] Even if laser cost is not a factor, scaling the power of the laser can have other adverse effects. Each powdered material has optimal melting properties that are determined by the power flux. If the power is too low, the powder will not melt, and if it is too high, the laser will drill into the material (key-holing). Increasing the laser power of a machine that is already operating at one of these sweet spots results in the necessary need to increase the laser area (spot size) to maintain the optimal power flux. Simply increasing the spot size will reduce the printable resolution, while splitting the laser into multiple beams will increase the complexity of the system.

[0032] In practice, currently available powder bed AM machines can be limited by part size, part manufacturing cost, part detail resolution, and part manufacturing throughput. Summary of the invention

[0033] This disclosure provides the following:

[0034] 1) A manufacturing method comprising the following steps:

[0035] Provide powder material;

[0036] providing an energy source capable of generating the energy beam;

[0037] directing the energy beam from the energy source toward an energy beam patterning unit to form a two-dimensional patterned energy beam;

[0038] directing the two-dimensional patterned energy beam toward the powder material to form a part having manipulation points; and

[0039] The manipulation points are engaged using a manipulation device to move the part.

[0040] 2) The method according to 1), wherein the manipulation device further comprises a robot arm.

[0041] 3) The method according to 1) further comprises the step of removing the manipulation point.

[0042] 4) The method according to 1) further comprising the step of reorienting the part using a manipulation device before adding more powder material.

[0043] 5) The method according to 1) further comprises the step of moving the part using the handling device to dispatch the part to another processing area.

[0044] 6) A part, comprising:

[0045] Printing a structure formed of at least one of a metal, a ceramic, a plastic, a glass-metal hybrid, a ceramic hybrid, a plastic hybrid, or a glass hybrid material and formed substantially solely using an additive manufacturing system including a two-dimensional patterned energy beam;

[0046] Wherein the printed structure has one or more manipulation points that can be engaged by a manipulation device.

[0047] 7) The part according to 6), wherein the manipulation point is a structure protruding from the part.

[0048] 8) The part according to 6), wherein the manipulation point is a temporary structure protruding from the part and removable using a directed energy beam.

[0049] 9) The part according to 6), wherein the manipulation point is a structure defined within the part.

[0050] 10) The part according to 6), wherein the manipulation point is a structure including a cavity defined within the part.

[0051] 11) The part according to 6), wherein the two-dimensional patterned energy beam is formed by multiple semiconductor lasers guided at an optically addressed light valve.

[0052] 12) A method of additive manufacturing, the method comprising:

[0053] limiting the exchange of gaseous matter between the interior of the housing and the exterior of the housing by means of the housing;

[0054] identifying a plurality of machines positioned within the housing;

[0055] performing, by each of the plurality of machines, a separate process of additive manufacturing comprising directing a patterned energy beam at a powder bed; and

[0056] During the execution, gaseous oxygen or water within the enclosure is maintained below atmospheric levels by a gas management system.

[0057] 13) The method of 12) wherein the housing comprises an airlock interface between the interior and the exterior.

[0058] 14) The method according to 12) further includes assistance by a person wearing a self-contained breathing apparatus within the housing.

[0059] 15) A method of additive manufacturing, the method comprising:

[0060] creating, by a first machine housed within a first housing, a first part via a first process including additive manufacturing using a patterned energy beam, wherein the first part has a weight greater than or equal to 2000 kilograms;

[0061] During said creating, maintaining gaseous oxygen or water within said first enclosure at below atmospheric levels by a first gas management system;

[0062] transporting the first part from inside the first enclosure, through the airlock, and to a location outside both the first enclosure and the airlock, as the airlock operates to buffer between the gas environment within the first enclosure and the gas environment outside the first enclosure; and

[0063] During the transport, the weight of the first part is continuously supported.

[0064] 16) The method according to 15), further comprising the step of transporting and continuously supporting the first part by using a wheeled vehicle.

[0065] 17) An additive manufacturing method, comprising:

[0066] Provides energy beams;

[0067] positioning an optically addressable light patterning unit for receiving the energy beam and emitting light as a two-dimensional patterned beam, wherein the optically addressable light patterning unit rejects energy not required for forming the two-dimensional patterned beam;

[0068] relaying the two-dimensional patterned beam and focusing it as a two-dimensional image on a powder bed; and

[0069] The rejected energy processing unit reuses the rejected energy.

[0070] 18) The additive manufacturing method according to 17) further comprises the steps of:

[0071] Provide powder material;

[0072] providing an energy source capable of generating the energy beam;

[0073] directing the energy beam from the energy source toward an energy beam patterning unit to form a two-dimensional patterned energy beam;

[0074] directing the two-dimensional patterned energy beam toward the powder material to form a part having manipulation points; and

[0075] The part is moved using a manipulation device to engage the manipulation point.

[0076] 19) A part created by the additive manufacturing method described in 17), the part comprising:

[0077] Printing a structure formed of at least one of a metal, a ceramic, a plastic, a glass-metal hybrid, a ceramic hybrid, a plastic hybrid, or a glass hybrid material and formed substantially solely using an additive manufacturing system including a two-dimensional patterned energy beam;

[0078] Wherein the printed structure has one or more manipulation points that can be engaged by a manipulation device.

[0079] 20) The additive manufacturing method according to 17) further comprises the steps of:

[0080] limiting, by means of an enclosure, the exchange of gaseous matter between an interior of the enclosure and an exterior of the enclosure;

[0081] identifying a plurality of machines positioned within the housing;

[0082] performing, by each of the plurality of machines, a separate process of additive manufacturing comprising directing a patterned energy beam at a powder bed; and

[0083] During the execution, gaseous oxygen within the enclosure is maintained below atmospheric levels by a gas management system.

[0084] 21) The additive manufacturing method according to 17) further comprises the steps of:

[0085] creating, by a first machine housed within a first housing, a first part via a first process including additive manufacturing using a patterned energy beam, wherein the first part has a weight greater than or equal to 2000 kilograms;

[0086] During said creating, maintaining gaseous oxygen within said first enclosure below atmospheric levels via a first gas management system;

[0087] transporting the first part from inside the first enclosure, through the airlock, and to a location outside both the first enclosure and the airlock, as the airlock operates to buffer between the gas environment within the first enclosure and the gas environment outside the first enclosure; and

[0088] During the transport, the weight of the first part is continuously supported. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Non-limiting and non-exhaustive embodiments of the present disclosure are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various figures unless otherwise specified.

[0090] Figure 1A An additive manufacturing system is shown;

[0091] Figure 1B is a top view of a structure formed on an additive manufacturing system;

[0092] Figure 2 An additive manufacturing method is shown;

[0093] Figure 3A is a base diagram showing an additive manufacturing system including a laser;

[0094] Figure 3B yes Figure 3A A detailed description of the light patterning unit shown;

[0095] Figure 3C is an embodiment of an additive manufacturing system having a "switch station" for directing and re-patterning light using a plurality of image relays;

[0096] Figure 3D A simple mirror image pixel remapping is shown;

[0097] Figure 3E showing a series of image transformation image relays for pixel remapping; and

[0098] Figure 3FA patternable electron energy beam additive manufacturing system is shown;

[0099] Figure 3G Shows Figure 3F A detailed description of the electron beam patterning unit shown in;

[0100] Figure 4A-4C Various beam combination embodiments are shown;

[0101] Figure 5A-Figure 5B An embodiment of a reflective light patterning unit is shown;

[0102] Figure 6 Light recycling is shown;

[0103] Figure 7 It is a polarized beam system;

[0104] Figure 8 is a flow chart of magnification changes and rack movements;

[0105] Figure 9A-9B The powder bed system and thermal management system are shown separately;

[0106] Fig.10 is a flow chart showing additive formation of a temporary wall containing powder;

[0107] Figure 11A-11B An embodiment of powder removal is shown;

[0108] Figure 12A-12B The manufacturing of long parts with multiple zones is shown;

[0109] Figure 13A-13C The handling of the part at the manipulation point is shown;

[0110] Fig.14 is a representative part with additively defined manipulation points;

[0111] Fig.15 is a flow chart showing the testing and characterization of powder samples;

[0112] Fig.16 is a diagram of a closed AM facility;

[0113] Fig.17 is an illustration of an additive manufacturing facility with multiple work areas. Detailed Description

[0114] In the following description, reference is made to the accompanying drawings which form a part of the specification and which are shown therein by way of illustration of 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 is understood that the various disclosed embodiments may be modified and other embodiments may be utilized without departing from the scope of the present disclosure. Therefore, the following detailed description is not to be considered in a limiting sense.

[0115] An additive manufacturing system having one or more energy sources (including one or more laser beams or electron beams in one embodiment) is positioned to emit one or more energy beams. A beam shaping optical device can receive one or more energy beams from an energy source and form a single beam. An energy patterning unit receives or generates a single beam and transmits a two-dimensional pattern to the beam, and can reject unused energy that is not in the pattern. An image relay receives the two-dimensional patterned beam and focuses it as a two-dimensional image to a desired position on a highly fixed or movable building platform (e.g., a powder bed). In some embodiments, some or all of any rejected energy from the energy patterning unit is reused.

[0116] In some embodiments, multiple beams from a laser array are combined using a beam homogenizer. The combined beam can be directed to an energy patterning unit that includes a transmissive or reflective pixel addressable light valve. In one embodiment, the pixel addressable light valve includes a liquid crystal module with a polarizing element and a light projection unit that provides a two-dimensional input pattern. The two-dimensional image focused by the image relay can be sequentially directed to multiple locations on the powder bed to build a 3D structure.

[0117] like Figure 1A As shown, the additive manufacturing system 100 has an energy patterning system 110 having an energy source 112 that can direct one or more continuous or intermittent energy beams to a beam shaping optical device 114. After shaping, if necessary, the beam is patterned by an energy patterning unit 116, typically directing some energy to a rejected energy processing unit 118. The patterned energy is relayed toward an item processing unit 140 by an image relay 120, typically as a two-dimensional image 122 focused near a bed 146. The bed 146 (with optional walls 148) can form a chamber that contains a material 144 dispensed by the material dispenser 142. The patterned energy directed by the image relay 120 can melt, fuse, sinter, merge, change the crystal structure, affect the stress pattern, or otherwise chemically or physically change the dispensed material 144 to form a structure with desired properties.

[0118] Energy source 112 generates photons (light), electrons, ions or other suitable energy beams or fluxes that can be guided, shaped and patterned. A variety of energy sources can be used in combination. Energy source 112 can include a laser, an incandescent lamp, concentrated solar energy, other light sources, an electron beam or an ion beam. Possible laser types include, but are not limited to: gas lasers, chemical lasers, dye lasers, metal vapor lasers, solid-state lasers (e.g., optical fibers), semiconductor (e.g., diode) lasers, free electron lasers, pneumatic lasers, "nickel-like" samarium lasers, Raman lasers, or nuclear pumped lasers.

[0119] The gas laser may include a laser such as a helium-neon laser, an argon laser, a krypton laser, a xenon ion laser, a nitrogen laser, a carbon dioxide laser, a carbon monoxide laser, or an excimer laser.

[0120] The chemical laser may include lasers such as a hydrogen fluoride laser, a deuterium fluoride laser, a COIL (chemical oxygen iodine laser), or an Agil (all gas phase iodine laser).

[0121] The metal vapor laser may include a helium cadmium (HeCd) metal vapor laser, a helium mercury (HeHg) metal vapor laser, a helium selenium (HeSe) metal vapor laser, a helium silver (HeAg) metal laser, a strontium vapor laser, a neon copper (NeCu) metal vapor laser, a copper vapor laser, a gold vapor laser, or a manganese (Mn / MnCl2) vapor laser.

[0122] Solid-state lasers may include, for example, 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 hydroxyborate Nd:YCa4O(BO3) lasers, and 3 Or simply referred to as Nd:YCOB, neodymium glass (Nd: glass) laser, titanium sapphire (Ti: sapphire) laser, thulium YAG (Tm: YAG) laser, ytterbium YAG (Yb: YAG) laser, ytterbium: 2O3 (glass or ceramic) laser, ytterbium-doped glass laser (rods, sheets / chips and fibers), holmium YAG (Ho: YAG) laser, chromium ZnSe (Cr: ZnSe) laser, cerium-doped lithium strontium (or calcium) aluminum fluoride (Ce: LiSAF, Ce: LiCAF), promethium 147-doped phosphate glass (147Pm +3 : glass) solid-state lasers, chromium-doped chrysoberyl (alexandrite) lasers, erbium-doped and erbium-ytterbium co-doped glass lasers, trivalent uranium-doped calcium fluoride (U:CaF2) solid-state lasers, divalent samarium-doped calcium fluoride (Sm:CaF2) lasers or F-center lasers.

[0123] The semiconductor laser may include, for example, 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.

[0124] For example, in one embodiment, a single Nd:YAG q-switched laser can be used in combination with multiple semiconductor lasers. In another embodiment, an electron beam can be used in combination with an array of ultraviolet semiconductor lasers. In other embodiments, a two-dimensional array of lasers can be used. In some embodiments with multiple energy sources, pre-patterning of the energy beam can be accomplished by selectively activating and deactivating the energy sources.

[0125] The beam shaping unit 114 may include a variety of imaging optical devices to combine, focus, diverge, reflect, refract, homogenize, adjust the intensity, adjust the frequency, or otherwise shape and direct one or more energy beams received from the energy source 112 toward the energy patterning unit 116. In one embodiment, wavelength selective mirrors (e.g., dichroic mirrors) or diffractive elements may be used to combine multiple light beams each having a different wavelength of light. In other embodiments, multi-faceted mirrors, micro lenses, and refractive or diffractive optical elements may be used to homogenize or combine multiple beams.

[0126] The energy patterning unit 116 may include static or dynamic energy patterning elements. For example, photons, electrons, or ion beams may be blocked by a mask having fixed or movable elements. In order to increase the flexibility and ease of image patterning, pixel addressable masking, image generation, or transmission may be used. In some embodiments, the energy patterning unit includes an addressable light valve, providing patterning alone or in conjunction with other patterning mechanisms. The light valve may be transmissive, reflective, or use a combination of transmissive and reflective elements. The pattern may be dynamically modified using electronic or optical addressing. In one embodiment, a transmissive optically addressed light valve is used to rotate the polarization of light passing through the valve, wherein the optically addressed pixels form a pattern defined by a light projection source. In another embodiment, a reflective optically addressed light valve includes a write beam for modifying the polarization of a read beam. In yet another embodiment, the electronic patterning device receives an address pattern from an electrical or photon excitation source and generates a patterned emission of electrons.

[0127] The rejected energy processing unit 118 is used to disperse, redirect, or utilize energy that is not patterned and passes through the energy pattern image relay 120. In one embodiment, the rejected energy processing unit 118 may include a passive or active cooling element that removes heat from the energy patterning unit 116. In other embodiments, the rejected energy processing unit may include a "beam dump" to absorb and convert any beam energy that is not used in defining the energy pattern into heat. In other embodiments, the beam shaping optical device 114 can be used to recycle the rejected beam energy. Alternatively or additionally, the rejected beam energy can be directed to the item processing unit 140 for heating or further patterning. In certain embodiments, the rejected beam energy can be directed to an additional energy patterning system or item processing unit.

[0128] The image relay 120 receives the patterned image (typically in two dimensions) from the energy patterning unit 116 and directs it toward the item processing unit 140. In a manner similar to the beam shaping optics 114, the image relay 120 may include optics for combining, focusing, diverging, reflecting, refracting, modulating intensity, modulating frequency, or otherwise shaping and directing the patterned image.

[0129] The article handling unit 140 may include a wall chamber 148 and a bed 146 and a material dispenser 142 for distributing materials. The material dispenser 142 can distribute, remove, mix, provide a gradual change or change in material type or particle size, or adjust the layer thickness of the material. The material may include metals, ceramics, glasses, polymer powders, other meltable materials that can undergo a thermally induced phase change from solid to liquid and back again, or a combination thereof. The material may further include a composite material of a meltable material and an infusible material, wherein any one or both components may be selectively targeted by an imaging relay system to melt the meltable component while leaving along the infusible material or subjecting it to vaporization / destruction / combustion or other destructive processes. In certain embodiments, slurries, sprays, coatings, wires, strips or sheets may be used. Unwanted materials may be removed for disposable use or recycling by using a blower, a vacuum system, sweeping, vibration, shaking, flipping or inversion of the bed 146.

[0130] In addition to material handling components, the article handling unit 140 may include components for holding and supporting 3D structures, mechanisms for heating or cooling the chamber, auxiliary or supporting optics, and sensors and controls for monitoring or adjusting material or environmental conditions. The article handling unit may fully or partially support a vacuum or inert gas atmosphere to reduce unwanted chemical interactions and mitigate the risk of fire or explosion (especially with reactive metals).

[0131] The control processor 150 may be connected to control any component of the additive manufacturing system 100. The control processor 150 may be connected to various sensors, actuators, heating or cooling systems, monitors, and controllers to coordinate operations. Various sensors including imagers, light intensity monitors, heat, pressure, or gas sensors may be used to provide information for control or monitoring. The control processor may be a single central controller, or may include one or more independent control systems. The controller processor 150 is provided with an interface for allowing input of manufacturing instructions. The use of various sensors allows various feedback control mechanisms that improve quality, production volume, and energy efficiency.

[0132] Figure 1B 1 is a bottom diagram showing a bed 146 of support material 144. Structure 149 is additively manufactured using a series of sequentially applied two-dimensional patterned energy beam images (squares in dashed outline 124). As will be appreciated, image patterns with non-square boundaries may be used, overlapping or interpenetrating images may be used, and images may be provided by two or more energy patterning systems. In other embodiments, images may be formed in conjunction with a directed electron beam or ion beam or in conjunction with a printing or selective jetting system.

[0133] Figure 2 is a flow chart showing one embodiment of an additive manufacturing process supported by the optical and mechanical components. In step 202, a material is placed on a bed, chamber, or other suitable support. The material may be a powder that can be melted, fused, sintered, induced to change the crystal structure, have stress patterns affected, or otherwise chemically or physically modified to form a structure with desired properties.

[0134] In step 204, unpatterned energy is emitted by one or more energy emitters, including but not limited to solid-state or semiconductor lasers, or power supplies that cause electrons to flow along a wire. In step 206, the unpatterned energy is shaped and modified (e.g., intensity modulated or focused). In step 208, this unpatterned energy is patterned, wherein in step 210, the energy that does not form a portion of the pattern is processed (this may include conversion into waste heat, or recycling as patterned or unpatterned energy). In step 212, the patterned energy, which now forms a two-dimensional image, is relayed toward the material. In step 214, the image is applied to the material, building a portion of the 3D structure. These steps can be repeated (loop 218) until the image (or a different and subsequent image) 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 completed, a new layer can be applied (loop 216) to continue building the 3D structure. These process cycles continue until the 3D structure is completed, at which time, the remaining excess material can be removed or recycled.

[0135] Figure 3A is an embodiment of an additive manufacturing system 300 using multiple semiconductor lasers as part of an energy patterning system 310. A control processor 350 may be connected to various sensors, actuators, heating or cooling systems, monitors, and controllers to coordinate the operation of multiple lasers 312, light patterning unit 316, and image relay 320, as well as any other components of system 300. These connections are generally represented by dashed outlines 351 surrounding the components of system 300. As will be appreciated, the connections may be wired or wireless, continuous or intermittent, and include capabilities for feedback (e.g., thermal heating may be adjusted in response to sensed temperature). Multiple lasers 312 may emit, for example, beams 301 of 1000 nm wavelength with a width of 90 mm x a height of 20 mm. Beam 301 is sized by imaging optics 370 to produce beam 303. Beam 303 is 6 mm wide by 6 mm high and is incident on a light homogenizer 372 which mixes the light together to produce a mixed beam 305. Beam 305 is then incident on an imaging assembly 374 which reshapes the light into beam 307 which is then incident on a hot cold mirror 376. Mirror 376 allows 1000 nm light to pass but reflects 450 nm light. A light projector 378 capable of projecting 1080p pixel resolution and low power light at 450 nm emits beam 309 which is then incident on hot cold mirror 376. Beam 307 and beam 309 are overlaid in beam 311 and both are imaged onto an optically addressed light valve 380 as an image 20 mm wide and 20 mm high. The image formed from the homogenizer 372 and projector 378 is recreated and overlaid on the light valve 380.

[0136] The optically addressed light valve 380 is excited by light (typically from the range of 400-500 nm) and prints a polarization rotation pattern in the transmitted beam 313 incident on the polarizer 382. The polarizer 382 separates the two polarization states, transmitting the p polarization into the beam 317 and reflecting the s polarization into the beam 315, which is then sent to the beam dump 318 which processes the rejected energy. As will be appreciated, in other embodiments, the polarization can be reversed, with the s polarization formed into the beam 317 and the p polarization reflected into the beam 315. The beam 317 enters the final imaging assembly 320 including the optics 384, which resizes the patterned light. The beam is reflected from the movable mirror 386 to the beam 319, which terminates in a focused image applied to the material bed 344 in the article processing unit 340. The depth of field in the image is selected to span multiple layers, providing optimal focus within several layers of error or offset.

[0137] The bed 390 can be raised or lowered (vertically indexed) within the chamber wall 388 that holds the material 344 dispensed by the material dispenser 342. In some embodiments, the bed 390 can remain stationary and the optics of the final imaging assembly 320 can be raised or lowered vertically. Material distribution is provided by a sweeping mechanism 392 that can evenly spread the powder held in the hopper 394, capable of providing a new layer of material as needed. The 6 mm wide by 6 mm high image can be directed sequentially by the movable mirror 386 at different locations on the bed.

[0138] When using powdered ceramic or metal materials in such an additive manufacturing system 300, the powder can be spread into a thin layer of about 1-3 particles thick on top of the base substrate (and subsequent layers) as the part is built. When the powder is melted, sintered, or fused by the patterned beam 319, it combines with the layer below to produce a solid structure. The patterned beam 319 can be operated in a pulsed manner at 40Hz, moving to the subsequent 6mm×6mm image position at intervals of 10ms to 0.5ms (expected 3 to 0.1ms) until the selected patterned area of ​​the powder has melted. The bed 390 then lowers itself to the thickness corresponding to one layer, and the sweeping mechanism 392 spreads a new layer of powder material. The process is repeated until the 2D layer establishes the desired 3D structure. In a particular embodiment, the item handling unit 340 can have a controlled atmosphere. This allows reactive materials to be manufactured in an inert gas or vacuum environment without the risk of oxidation or chemical reactions or fire or explosion (if reactive metals are used).

[0139] Figure 3B Pictured Figure 3A The light patterning unit 316 operates in more detail. Figure 3BAs seen in FIG. 3 , a representative input pattern 333 (here the number “9” is seen) is defined in the light of the 8×12 pixel array projected when beam 309 is directed toward mirror 376. Each gray pixel represents a pixel filled with light, while white pixels are not illuminated. In practice, each pixel can have a different light level, including no light, partial light intensity, or maximum light intensity. Unpatterned light 331 forming beam 307 is directed and passes through hot / cold mirror 376, where beam 307 is combined with patterned beam 309. After reflection by hot / cold mirror 376, patterned beam 311 formed by the overlap of beams 307 and 309 in beam 311 and both are imaged onto optically addressed light valve 380. The optically addressed light valve 380, which rotates the polarization state of the unpatterned light 331, is excited by the patterned beams 309, 311 to selectively not rotate the polarization state of polarized light 307, 311 in the pattern of the number “9” into beam 313. Unrotated light representing pattern 333 in beam 313 is then allowed to pass through polarizer mirror 382, ​​resulting in beam 317 and pattern 335. Polarized light in the second rotational state is rejected by polarizer mirror 382 into beam 315 carrying negative pixel pattern 337 consisting of a blank numeral "9".

[0140] Other types of light valves may be used in place of or in combination with the light valves described. Reflective light valves or light valves based on selective diffraction or refraction may also be used. In some embodiments, non-optically addressable light valves may be used. These may include, but are not limited to, electrically addressable pixel elements, movable mirrors or micro-mirror systems, piezoelectric or micro-actuated optical systems, fixed or movable masks or shields, or any other conventional system capable of providing high intensity light patterns. For electron beam patterning, these valves can selectively emit electrons based on address locations, thereby injecting a pattern on the electron beam leaving the valve.

[0141] Figure 3C is an embodiment of an additive manufacturing system including a switchyard system that enables reuse of patterned two-dimensional energy. Figure 1AIn the discussed embodiment, the additive manufacturing system 220 has an energy patterning system with an energy source 112 that directs one or more continuous or intermittent energy beams to a beam shaping optical device 114. After shaping, the beam is patterned in two dimensions by an energy patterning unit 230, typically directing some of the energy to a rejected energy processing unit 222. The patterned energy is relayed toward one or more item processing units 234A, 234B, 234C, or 234D through one of a plurality of image relays 232, typically as a two-dimensional image focused near a movable or fixed height bed. The bed (with optional walls) can form a chamber that holds the material dispensed by the material dispenser. The patterned energy directed by the image relay 232 can melt, fuse, sinter, merge, change the crystal structure, affect the stress pattern, or otherwise chemically or physically change the dispensed material to form a structure with desired properties.

[0142] In this embodiment, the rejected energy processing unit has multiple components to allow the reuse of rejected patterned energy. Repeaters 228A, 228B, and 228C can transmit energy to generator 224, heating / cooling thermal management system 225, or energy collector 226, respectively. Optionally, repeater 228C can direct the patterned energy to image repeater 232 for further processing. In other embodiments, the patterned energy can be directed by repeater 228C to repeaters 228B and 228A to be inserted into the energy beam provided by energy source 112. The use of image repeater 232 can also reuse patterned images. The image can be redirected, inverted, mirrored, sub-patterned, or otherwise transformed to be distributed to one or more item processing units 234A-234D. Advantageously, the reuse of patterned light can improve the energy efficiency of the additive manufacturing process and in some cases improve the energy intensity for the bed, or reduce manufacturing time.

[0143] Figure 3D 235 is a base diagram showing a simple geometric transformation of a rejected energy beam for reuse. An input pattern 236 is directed to an image relay 237A which provides a mirrored pixel pattern 238. As will be appreciated, more complex pixel transformations are possible, including geometric transformations, or pattern remapping of individual pixels and groups of pixels. Such remapped patterns can be directed directly to an article handling unit to increase throughput or beam intensity, rather than being wasted in a beam dump.

[0144] Figure 3E is a bottom diagram 235 showing multiple conversions of rejected energy beams for reuse. An input pattern 236 is directed into a series of image relays 237B-237E which provide a pixel pattern 238.

[0145] Figure 3F and Figure 3G A non-light based energy beam system 240 is illustrated that includes a patterned electron beam 241 capable of producing, for example, a "P" shaped pixel image. A high voltage power system 243 is connected to an optically addressable patterned cathode unit 245. In response to the application of a two-dimensional patterned image by a projector 244, the cathode unit 245 is excited to emit electrons wherever the patterned image is optically addressed. Focusing of the electron beam pattern is provided by an image relay system 247 that includes imaging coils 246A and 246B. Final positioning of the patterned image is provided by a deflection coil 248 that is capable of moving the patterned image to a desired location on the bed of an additively manufactured part 249.

[0146] In another embodiment supporting light recycling and reuse, multiple light beams multiplexed from one or more light sources are provided. The multiple light beams can be reshaped and mixed to provide a first light beam. A spatial polarization pattern can be applied to the first light beam to provide a second light beam. The polarization state of the second light beam can be separated to reflect a third light beam, and the third light beam can be reshaped into a fourth light beam. The fourth light beam can be introduced as one of the multiple light beams to produce a fifth light beam. In fact, this or similar systems can reduce the energy costs associated with additive manufacturing systems. By collecting, beam combining, homogenizing and reintroducing unwanted light rejected by a spatial polarization valve or light valve operating in a polarization modification mode, the overall transmitted light power may not be affected by the pattern applied by the light valve. This advantageously results in the light passing through the light valve being effectively redistributed into a desired pattern, increasing the light intensity proportional to the amount of patterned area.

[0147] Combining beams from multiple lasers into a single beam is one way to increase beam intensity. In one embodiment, wavelength selective mirrors or diffraction elements can be used to combine multiple beams, each with a different wavelength of light. In some embodiments, reflective optical elements that are insensitive to wavelength-dependent refractive effects can be used to direct the multi-wavelength beam.

[0148] Patterned light can be guided using a movable reflector, a prism, a diffractive optical element, or a solid-state optical system that does not require substantial physical movement. In one embodiment, the magnification and image distance associated with the intensity and pixel size of the incident light at the position of the top surface of the powder bed can be determined for a three-dimensional (3D) printing job of additive manufacturing. One of a plurality of lens assemblies can be configured to provide incident light with magnification, wherein the lens assembly includes both a first group of optical lenses and a second group of optical lenses, and the second group of optical lenses can be exchanged from the lens assembly. Rotation of one or more groups of reflectors mounted on a compensation rack and a final reflector mounted on a building platform rack can be used to guide the incident light from the precursor reflector to the position of the top surface of the powder bed. The translational movement of the compensation rack and the building platform rack can also ensure that the distance of the incident light from the precursor reflector to the position of the top surface of the powder bed is substantially equal to the image distance. In fact, this can enable rapid changes in the beam delivery size and intensity of the position of the building area across different powder materials while ensuring high availability of the system.

[0149] In some embodiments, multiple build chambers, each having a build platform to hold a powder bed, may be used in conjunction with multiple optomechanical assemblies arranged to receive and direct one or more incident energy beams into the build chamber. Multiple chambers allow for simultaneous printing of one or more print jobs in one or more build chambers. In other embodiments, removable chamber sidewalls may simplify removal of printed objects from the build chamber, allowing for rapid exchange of powdered materials. The chamber may also be equipped with adjustable process temperature control.

[0150] In another embodiment, one or more build chambers may have the build chamber maintained at a fixed height while the optics are moved vertically. The distance between the final optics of the lens assembly and the top surface of the powder bed can be set to be substantially constant by shifting the final optics upward a distance equivalent to the thickness of the powder layer while maintaining the build platform at a fixed height. Advantageously, since precise micron-scale movement of the build platform is not required, large and heavy objects can be manufactured more easily than if the build platform was moved vertically. Typically, build chambers for metal powders with volumes greater than 0.1-0.2 cubic meters (i.e., greater than 100-200 liters or weighing more than 500-1,000 kilograms) will benefit most from maintaining the build platform at a fixed height.

[0151] In one embodiment, a portion of the layer of the powder bed can be selectively melted or fused to form one or more temporary walls from the fused portion of the layer of the powder bed to accommodate another portion of the layer of the powder bed on the build platform. In selected embodiments, fluid channels can be formed in one or more first walls to achieve improved thermal management.

[0152] Improved powder handling can be another aspect of the improved additive manufacturing system. The build platform supporting the powder bed can be tilted, inverted, and shaken to substantially separate the powder bed from the build platform into a hopper. The powder material forming the powder bed can be collected in the hopper for reuse in subsequent printing jobs. The powder collection process can be automated, and vacuum or gas jet systems can also be used to aid in powder removal and removal.

[0153] Some embodiments of the disclosed additive manufacturing system can be configured to easily handle parts that are longer than the available chamber. Continuous (long) parts can be sequentially advanced from a first zone to a second zone in the longitudinal direction. In the first zone, selected particles of granular material can be merged. In the second zone, unmerged particles of granular material can be removed. The first portion of the continuous part can advance from the second zone to the third zone, while the last portion of the continuous part is formed in the first zone, and the first portion remains in the same position occupied by the first portion in the first zone and the second zone in the lateral and transverse directions. In fact, additive manufacturing and cleaning (e.g., separation and / or recovery of unused or unmerged granular material) can be performed in parallel (i.e., simultaneously) at different locations or zones on the part conveyor without stopping to remove granular material and / or parts.

[0154] In another embodiment, additive manufacturing capabilities can be increased by using an enclosure that limits gaseous species exchange between the interior of the enclosure and the exterior of the enclosure. An airlock provides an interface between the interior and the exterior; the interior has multiple additive manufacturing chambers, including those that support powered bed melting. A gas management system maintains gaseous oxygen inside at or below a limiting oxygen concentration, thereby increasing the flexibility of the types of powders and processes that can be used with the system.

[0155] In another manufacturing embodiment, performance can be improved by having the 3D printer contained within the enclosure, with the printer being able to create parts weighing greater than or equal to 2,000 kilograms. 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 a part from inside the enclosure to a location outside both the enclosure and the airlock via an airlock (since the airlock operates to buffer between the gas environment within the enclosure and the gas environment outside the enclosure).

[0156] Other manufacturing embodiments involve real-time collection of powder samples in a powder bed fusion additive manufacturing system. An ingester system is used for in-process collection and characterization of powder samples. The collection can be performed periodically and the results of the characterization lead to adjustments to the powder bed fusion process. The ingester system can optionally be used for one or more of audits, process adjustments, or actions, such as modifying printer parameters or verifying the correct use of authorized powder materials.

[0157] It is described that another improvement to the additive manufacturing process can be provided by using a manipulator device such as a crane, lifting frame, robotic arm or similar device that allows manipulation of parts that are difficult or impossible for a person to move. The manipulator device can grasp various permanent or temporary additive manufacturing manipulation points on the part to enable repositioning or maneuvering of the part.

[0158] Figure 4A A beam combining system 400 is shown having multiple wavelength semiconductor lasers and using transmissive imaging optics. As will be appreciated, the laser powers and wavelengths discussed are exemplary, as are the selected wavelengths reflected or transmitted by the wavelength filters. A greater or lesser number of lasers may be used with appropriate changes in the positioning and use of the wavelength filters. In some embodiments, solid-state lasers may be replaced by or used in combination with semiconductor lasers. In other embodiments, such as with reference to Figure 1A Other laser types discussed including gas, chemical or metal vapor lasers may be used. In one embodiment, the recycling and reuse of rejected light may replace the laser. Rejected light available in an additive manufacturing system may be collected, homogenized and reintroduced into the beamline. Advantageously, recycling and reuse of rejected light may increase beam intensity and reduce energy costs associated with the system.

[0159] exist Figure 4A, a semiconductor laser 406 of a first wavelength (1020 nm) emits a photon beam 407 of 33.3 kW at a corresponding wavelength, and a semiconductor laser 408 of a second wavelength (1000 nm) emits a photon beam 409 of 33.3 kW, which are then combined using a wavelength filter 410 that transmits 1020 nm photons but reflects 1000 nm photons. This results in a combined two-wavelength beam 411 of 66.6 kW. A semiconductor laser 412 of a third wavelength (980 nm) emits a photon beam 413 of 33.3 kW at a corresponding wavelength, which is then combined with beam 411 using a wavelength filter 414. Wavelength filter 414 transmits 1020 and 1000 nm, but reflects the 980 nm beam, producing a three-wavelength beam 415 of 99.9 kW. A semiconductor laser 417 of a fourth wavelength (960 nm) emits a photon beam 418 of 33.3 kW of the corresponding wavelength, which is then combined with beam 415 using a wavelength filter 416 that transmits 1020 nm, 1000 nm, and 980 nm photons but reflects 960 nm, resulting in a four-wavelength beam 419 of 133.2 kW. The beam enters the optical imaging system with a beam size of, for example, 20 mm x 20 mm and a divergence of 1.1 degrees at lens 420. Lens 420 is a series of lenses using two materials (C79-79 and ULE7972), each with a different refractive index to eliminate the effects of wavelength variations on the ability to image the beam. The beam leaves the optical system at 421, which is a series of lenses using three materials, ZeruDur, ULE 7972, and C79-79, to eliminate the effects of wavelength variations on the ability to image the beam. The beam intensity at 422 increases due to passing through the optical system and is now 6 mm wide by 6 mm high with a divergence of 3.67 degrees, resulting in an intensity of 370 kW / cm 2 , sufficient for additive manufacturing of powdered stainless steel metals, for example.

[0160] To obtain optimal performance, the correct choice of lens material is necessary. Transmissive optical devices such as lens 420 can be made of fused silica glass. It reduces thermal expansion problems due to its extremely low absorption coefficient at wavelengths near 1000nm, and reduces thermal expansion of the lens due to the extremely low thermal expansion coefficient of fused silica. The use of fused silica allows the optical device to withstand higher strength without heating and expansion, which may cause fractures, changes in the refractive index of the glass, changes in the shape of the glass, and consequent changes in focus. Unwanted optical changes can also be reduced by using two or more materials. Each material can have a different refractive index that varies differently with wavelength. When used in the appropriate combination, changes in refractive index and optical path length are offset, and there is no change in focal length with changes in wavelength.

[0161] Figure 4BAn alternative beam combining system 401 is illustrated that includes a combination of multiple wavelength semiconductor lasers and uses reflective imaging optics to reduce the previously discussed problems associated with transmissive optics. Figure 4A As with the beam combining system 400 of FIG. 4 , it will be appreciated that the laser powers and wavelengths discussed in the system 401 are exemplary, as are the selected wavelengths reflected or transmitted by the wavelength filters. A greater or lesser number of lasers may be used with appropriate variations in the positioning and use of the wavelength filters. A variety of types of lasers may be used, and in one embodiment, the recovery and reuse of rejected light may replace the lasers. Rejected light available in an additive manufacturing system may be collected, homogenized, and reintroduced into the beamline. Advantageously, reflective optics improve problems associated with semiconductor laser chirp (a shift in wavelength over time) both during startup transients and during their lifetime. The use of reflective optical elements prevents detuning of the focus of the diode laser due to this effect, and does not affect the resolution or imaging capabilities achieved. Additionally, by using reflective optics, wavelength differences caused by changes in the operating temperature of the laser do not affect the resolution or imaging capabilities.

[0162] exist Figure 4B , a semiconductor laser 423 of a first wavelength (1020 nm) emits a 33.3 kW photon beam 424 of a corresponding wavelength, and a semiconductor laser 425 of a second wavelength (1000 nm) emits a 33.3 kW photon beam 426 of a corresponding wavelength. These beams are combined using a wavelength filter 427 that transmits 1020 nm photons but reflects 1000 nm photons, generating a 66.6 kW dual-wavelength beam 428. A semiconductor laser 429 of a third wavelength (980 nm) emits a 33.3 kW photon beam 430 of a corresponding wavelength. These beams are combined with beam 428 using a wavelength filter 431 that transmits 1020 and 1000 nm but reflects 980 nm, generating a 99.9 kW three-wavelength beam 432. A semiconductor laser 433 of a fourth wavelength (960 nm) emits a 33.3 kW photon beam 434 of a corresponding wavelength. These beams are combined with beam 432 using a wavelength filter 435 that transmits 1020nm, 1000nm, and 980nm photons but reflects 960nm, producing a four-wavelength beam 436 of 133.2kW. The beam enters the optical imaging system with a beam size of, for example, 20mm x 20mm and a divergence of 1.1 degrees at reflective optics 437. The reflective optics are not wavelength dependent and do not affect the ability to image the beam. The beam exits the beam combining optical system 401 at reflective optics 438. The intensity of beam 439 has increased due to passing through the optical system and is now 6mm wide x 6mm high with a divergence of 3.67 degrees, resulting in an intensity of 370kW / cm 2 , sufficient for additive manufacturing of metals such as powdered stainless steel.

[0163] Figure 4C An alternative embodiment of a beam combining system 440 is described that combines beams 443 from the same or multiple wavelength lasers 442 using a diffractive imaging optic 444. The diffractive optical element may be shaped or patterned to receive the beams 443 and reflect them along substantially the same beam axis. As will be appreciated, although in Figure 4C A diffractive optical element that reflects a beam is shown in FIG. 1 . In other embodiments, the diffractive optical element may transmit a beam, or a combination of reflective, transmissive or other suitable beam steering optical components or elements may be used.

[0164] Figure 5A A reflective optically addressed light valve system 500A useful in additive manufacturing systems such as disclosed herein. A reflective light valve does not require light to be transmitted through a transparent semiconductor for light patterning, where even a small amount of absorption can result in undesirable and catastrophic heating at high average power levels. A reflective light valve can also allow for easier cooling on the reflective surface, while cooling is performed on opposite sides of the writing and reading beams incident.

[0165] As in Figure 5AAs seen in FIG. 5 , a reflective optically addressed light valve system 500A is capable of patterning an energy beam and consists of a highly transmissive layer 501, a twisted nematic (TN) liquid crystal layer 502, and a photoconductor layer 503. The highly transmissive layer is optically transparent to 1000 nm and 700 nm light and is made of a glass substrate (C79-79 fused silica) 501 with an anti-reflective coating on both sides 504 and 506. An indium tin oxide (ITO) conductive coating is applied to the highly transmissive layer 501 at 505. Layer 502 is anchored to 506 and 510 by anchoring substrates 507 and 509. The exact spacing of 502 is given by the size of the spacer balls 508 defining a 2.5 micron gap, which is adjusted for maximum contrast ratio when passing 1000 nm light in a double pass. Layer 503 is made of a single crystal silicon semiconductor with a highly reflective dielectric coating applied at 510 which is transparent to 700 nm but reflective at 1000 nm. Layer 511 is another layer of ITO, which has solder joints 512 attached and is connected to layer 505 through another solder joint 513 via an AC voltage source 514. A patterned writing beam is emitted from a projector source at 700 nm and impinges on 503 after being transmitted through 504, 501, 505, 506, 507, 502, 509 and 510. Where the writing beam strikes 503, electrons move from the valence band to the conduction band, greatly increasing the local conductivity of 503, allowing current to flow from 511 through 503, 510, 509, 502, 507 and 506 to 505. When current flows through the TN liquid crystal 502, it causes a rotation in the liquid crystal 502, causing a polarization rotation in the transmitted light. The "read" beam 516 is p-polarized and is incident on 510 after being transmitted through 504, 501, 505, 506, 507, 502, and 509, where it reflects and transmits through 509, 502, 507, 506, 505, 501, and 504 back to exit the light valve system 500A. The beam is then incident on polarizer 517, which reflects resulting in s-polarization of reflected beam 518 and transmits resulting in p-polarization of transmitted beam 519. Although absorption in the device is very low, the HR coating 509 is not completely reflective and some energy is absorbed. This energy is removed by radiative, conductive, or convective cooling 520.

[0166] Figure 5BAn alternative reflective optically addressed light valve 500B with cooling on one side is shown, where the writing and reading beams are incident from different sides. The valve consists of a highly transmissive layer 521, a twisted nematic (TN) liquid crystal layer 522, and a photoconductor layer 523. The highly transmissive layer is optically transparent for 1000 nm and 700 nm light, made of a glass substrate (C79-79 fused silica) 521 with an anti-reflective coating on both sides 524 and 526. An indium tin oxide (ITO) conductive coating is applied to 521 at 525. Layer 522 is anchored to 526 and 530 by anchoring substrates 527 and 529. The exact spacing of 522 is given by the size of the spacer balls 528 defining a 2.5 micron gap, which is adjusted for maximum contrast ratio when passing 1000 nm light in a double pass. Layer 523 is made of single crystal silicon semiconductor, with a highly reflective dielectric coating applied at 530, which reflects at 1000 nm. Layer 531 is another layer of ITO, which has a solder joint 532 attached and is connected to layer 525 through another solder joint 533 via an AC voltage source 534. A patterned writing beam is emitted from the projector source at 700 nm and is incident on 523 after passing through an optional convective / conductive substrate and through the ITO coating 531. Where the writing beam strikes 503, electrons move from the valence band to the conduction band, greatly increasing the local conductivity of 523, allowing current to flow from 531 through 523, 530, 529, 522, 527 and 526 to 525. When current flows through the TN liquid crystal 522, it causes a rotation in the liquid crystal 522, causing a polarization rotation in the transmitted light. The "read" beam 536 is p-polarized and is incident on 530 after transmitting through 524, 521, 525, 526, 527, 522, and 529, where it reflects and transmits back through 509, 522, 527, 526, 525, 521, and 524 to exit the light valve. The beam is then incident on polarizer 537, which reflects resulting in s-polarization of reflected beam 538 and transmits resulting in p-polarization of transmitted beam 539. Although absorption in the device is very low, the HR coating 529 is not completely reflective and some energy is absorbed. This energy is removed by radiation, conduction, or convection cooling.

[0167] To aid in better understanding and appreciating various system embodiments, including alternative or additional optical systems, chamber designs, powder handling systems and methods, structure formation, part creation and manipulation, use of a variety of additive manufacturing systems, and high throughput manufacturing methods suitable for automated or semi-automated factories; the following disclosure will help to appreciate and understand the various novel aspects of the disclosed systems, methods, and structures.

[0168] Figure 6The layout of an exemplary apparatus 600 for laser recycling in an additive manufacturing process is shown. Apparatus 600 may include one or more light sources, such as but not limited to light sources 601, 602, and 603. In some embodiments, light sources 601, 602, and 603 may include lasers. Alternatively, other types of light sources, such as solid-state lasers, may be used. In some embodiments, each or at least one of light sources 601, 602, and 603 may emit 11.1 kW of p-polarized light at 700 nm, with a size of 7.9 cm×7.9 cm and a divergence of 7.6 mrad. The light beams emitted by light sources 601, 602, and 603 may be multiplexed together by a first optical component 604, which may include a series of mirrors to allow the beams to be as close together as possible. These beams are then reshaped and mixed with an optical device 605 to produce a beam 606 of 33.3 kW, 4.7 cm×4.7 cm, and a divergence of 70.4 mrad. Beam 606 may then be incident on a spatial polarization valve 607, which may apply a spatial polarization pattern to beam 606 by rotating the polarization of a selected pixel from p-polarization to s-polarization to provide beam 608. By appropriate modification, a selected pixel may be formed by rotating from s-polarization to p-polarization to provide a beam. In other embodiments, grayscale pixels may be created by partial rotation. After interacting with polarizer 609, the s-polarization state of beam 608 may be reflected into beam 610. The exact fraction may be given as a function of the fraction of light patterned by spatial polarization valve 607. Beam 610 may enter a second optical component 611, which may include a series of mirrors, reshaping lenses, wave plates, or other optical components, and beam 610 may be modified to a 7.9 cm x 7.9 cm beam and then reintroduced into the system as if it were light source 612, together with the original one or more light sources 601, 602, and 603.

[0169] The process for light recycling may include the step of multiplexing a plurality of light beams including at least one or more light beams from one or more light sources 601, 602, and 603. The plurality of light beams may be reshaped and mixed to provide a first light beam. The spatial polarization valve 607 of the device 600 applies a spatial polarization pattern on the first light beam to provide a second light beam. The polarizer 609 of the device 600 separates the polarization state of the second light beam 608 to reflect a third light beam (e.g., beam 610). The second optical component 611 of the device 600 reshapes the third light beam into a fourth light beam, and the fourth light beam is introduced into the first optical component 604 as one of the plurality of light beams to generate a fifth light beam (e.g., beam 613), which is emitted through the polarizer 609 and is not reflected by the polarizer 609.

[0170] Figure 7An example optical assembly 700 is shown that combines polarization according to the present disclosure to achieve 2 times the original semiconductor laser intensity (limit value). Semiconductor lasers are typically polarized to about 70-90% in one polarization state. When using polarization rotation methods to pattern light, 10-20% of the light in the undesirable polarization state may not be used (rejected). To avoid this loss, polarization combining and patterning can be used to improve transmission efficiency or increase the combined intensity by 2 times, or both.

[0171] In one embodiment, two or more light beams having a first intensity are provided, each of the two or more light beams being polarized and having a majority polarization state and a minority polarization state. A corresponding polarization pattern is applied to the majority polarization state of each of the two or more light beams, and the two or more light beams are combined to provide a single light beam having a second intensity greater than the first intensity. In a second embodiment, more than one laser of any polarization state may be used. A polarizer is used to separate the beams into their respective polarization states, and the beams of the corresponding polarization states are spatially stacked together by spatial positioning, thereby producing two effective beams, one beam for each polarization state. The two beams having different polarization states are then passed through an optical modulator associated with their perspective polarization states, and then beam combined by applying a polarization state pattern in the beam, and then by polarization combination. The method uses all the light in the process, which allows for higher laser utilization, achieves minimal to no loss due to changes in polarization states, and achieves better system efficiency.

[0172] The optical assembly 700 may include Figure 7, as described below. Light sources 701 and 702 are each used as a high power photon source. In some embodiments, light sources 701 and 702 can be semiconductor laser arrays each with 33.3kW power, emitting photons of 1000nm, shaped and mixed into a square beam of 20mm wide by 20mm. The emitted light can be 90% polarized in the majority state p, resulting in light beams 703 and 704. The emitted light beams 703 and 704 can be incident on polarizers 705 and 706, respectively. Polarizers 705 and 706 can reflect minority state s-polarization to produce light beams 709 and 710, which can be incident on beam dump 711. Polarizers 705 and 706 can transmit p polarization to produce light beams 707 and 708, which can be incident on polarization rotating optical addressing light valves 712 and 713, respectively. Each of the light valves 712 and 713 can cause the same image to be applied to the beams 708 and 707 to create a polarization pattern, and can spatially flip 20% of the "pixels" from p-polarization to s-polarization in the desired pattern, resulting in beams 714 and 715. Beams 714 and 715 can be incident on polarizers 716 and 717, respectively. Polarizers 716 and 717 can reflect s-polarization to produce beams 718 and 719, respectively, which can contain 20% of the energy and can be collected into a beam dump 720. Polarizers 716 and 717 can transmit p-polarization to produce beams 721 and 722. Beam 722 can be incident on a half-wave plate 723, which rotates the polarization of each photon by half a wave, thereby converting the p-polarization to s-polarization to produce beam 724. Beams 721 and 724 may be incident on mirrors 725 and 726, respectively, to produce beams 727 and 728. Beam 727 may be incident on mirror 729 to produce beam 730, which may be incident on polarizer 731 in p-polarization. Beam 728 in s-polarization may be incident on polarizer 731, which may reflect the s-polarization of beam 728 and transmit the p-polarization of beam 730 to produce beam 732. Beam 732 may be a beam of twice the intensity of a single polarization state from light source 701 or 702, with a total initial intensity of 1.8 times the original due to 90% of the initial polarization, and proportionally less than the total initial intensity due to 20% of the polarization mapped image being applied at light valves 712 and 713. The total propagation intensity at beam 732 may be 1.44 times the initial intensity for a total transmission power of 47.52 kW emitted. Imaging to the original 20x20mm square, if the divergence angle remains unchanged, the final intensity can be 11.88kW / cm 2 .

[0173] In powder bed fusion additive manufacturing, as the powder material is processed (with or without chemical bonding), a source image of a beam of light with sufficient energy is directed to a location on the top surface (print surface) of the powder bed to form the overall object. The resolution (or pixel size) of an optical system used for powder bed fusion additive manufacturing depends on whether the print surface coincides with the focal plane of the final optics in the optical system, or in the case of an imaging system, whether the distance between the lens of the optics performing the imaging operation and the imaging plane is maintained at a substantially constant distance for a given lens configuration. In order to be able to print large objects in powder bed fusion additive manufacturing, precise control of the image position on the print surface and the distance between the lenses is necessary to maintain the resolution or pixel size at every possible location on the top surface of the powder. Different powder materials may require different beam intensities or energies because the respective bond energy thresholds are different. If a change in intensity is required when changing powder type or powder size distribution, the optical system may need to be shut down to reinstall and realign the imaging lens.

[0174] To address issues related to intensity and resolution variations, the procedure is described below. Figure 8 800 is a flowchart illustrating steps for using a dynamic optical assembly that may include an image relay gantry. In step 810, information is obtained or otherwise determined to find the minimum resolution (pixel size of the incident light) of an object to be printed in a powder bed fusion additive manufacturing system. Based on the intensity and resolution requirements, the magnification of the incident light containing image information and the image distance of the dynamic optical assembly are calculated. The magnification can convert a first size of an image at a precursor image plane to a second size of an image at a printing surface (top surface of the powder bed). The incident light can originate from an energy source and pass through a precursor image plane where image information can be created. Process 800 can involve storing geometric data of the object, position of the dynamic optical assembly, and rotation control data.

[0175] At step 820, process 800 may include configuring the mechanical assembly and one or more lens assemblies to achieve a magnification suitable for the powder material obtained at 810. Configuration of one of the mechanical assembly and the lens assembly may involve rotation of the mechanical assembly, exchange of the second set of optical lenses, or removal of the second set of optical lenses.

[0176] At step 830, multiple rotations may be performed to direct incident light from the precursor image plane to the print surface at a desired location on the print surface (e.g., the top surface of the powder bed) at each successive step of the powder bed fusion additive manufacturing. At step 840, the dynamic optical assembly may perform multiple translational motions to maintain a constant image distance from the precursor image plane to each location of the print surface (e.g., the top surface of the powder bed) at each successive step of the powder bed fusion additive manufacturing. Vertical motion of the powder bed or optical assembly may be used to maintain a fixed separation of the powder bed relative to the final lens.

[0177] The apparatus implementing process 800 may include a layer of powder material distributed on the top surface of a powder bed supported by a build platform. A source image of incident light located at a precursor image plane is incident on a lens assembly in a lens barrel. The lens assembly may be configured by rotation of the lens barrel, which enables the exchange of a second set of optical lenses, the removal of a second set of optical lenses, the use of a dynamic lens that changes shape, electronic lens exchange, a beam redirection system, an optoelectronically controlled refractive beam steering device, or a combination thereof, to have an appropriate magnification for the powder material. After passing through the lens assembly, an object image of a different size than the source image appears, and the object image is modified according to the magnification of the lens assembly. A beam containing image information is incident on a precursor reflector and directed to a reflector mounted on a compensation frame, the beam is reflected on the reflector, and then incident on a final reflector mounted on a build platform frame. The final reflector directs the beam containing image information through a final lens toward the top surface of the powder bed, and reproduces and magnifies the object image in an image plane that may be formed thereon. The powder material on the powder bed may melt to form the shape of the object image. The build platform rack then moves to the next position until the designated location on the top surface of the powder bed bonds with the layer. A new layer of powder material is dispensed again, and the build platform can move down a distance equal to the thickness of the powder material layer to maintain a constant distance from the build platform rack. The cycle begins for the new layer to continue the additive printing process.

[0178] Fig.9AAn example scene 900 is shown at an intermediate point in a powder bed fusion additive manufacturing printing process according to the present disclosure. Example scene 900 shows upward movement of a part in a build chamber while controlling depth of field using a fixed build platform 930. The build platform 930 can have an area of ​​0.5 meters by 1 meter over which powder can be dispensed during a printing cycle. In one embodiment, the build platform 930 is moved to a position below the gantry table 905 and locked into place. Vertical columns 903(1)-903(4), each at a height of 3 meters, support a gantry 907 mounted on the gantry table 905. A powder dispensing unit 910, a compaction feature 911, and a reflector 917 can be mounted on the gantry 907 for translational movement in a horizontal plane. The gantry table 905 is shown at a height above Fig.9A 920 to reflect that printing may be in progress. Powder bed 920 contains powder layers and printed objects at various stages of completion. A new powder layer 925 is dispensed from powder dispensing unit 910, which includes powder diffusion and compaction. Beam 921 incident from a print head (not shown) can be reflected from reflector 917 to become beam 922 that hits position 923 in new powder layer 925. Printing can occur by melting, sintering, melting or otherwise merging powder at position 923 in new powder layer 925. The distance between reflector 917 and position 923 in new powder layer 925 is the depth of field that needs to be strictly controlled to meet resolution requirements. Arrow 970 indicates the upward movement of gantry 905, which supports gantry 905, powder dispensing unit 910, reflector 917, and in some embodiments, surrounding chambers or walls. During this process, build platform 930 remains locked in place, and frame 907 (and / or the chamber and chamber walls) moves relative to build platform 930. This arrangement is particularly useful for the embodiments discussed below, where build platform 930 is large and will need to support large amounts of heavy material that is not easily moved in a vertical direction with the required precision.

[0179] In some embodiments, the building platform 930 of the example scene 900 may have an area greater than 0.25 square meters. Alternatively, the building platform 930 of the example scene 900 may have an area greater than 0.5 square meters. Alternatively, the building platform 930 of the example scene 900 may have an area greater than 1 square meter. Alternatively, the building platform 930 of the example scene 900 may have an area greater than 5 square meters. Alternatively, the building platform 930 of the example scene 900 may have an area greater than 10 square meters. Alternatively, the building platform 930 of the example scene 900 may have an area greater than 50 square meters.

[0180] In some embodiments, the powder bed 920 of the printed object including the example scene 900 may have a mass greater than 10 kilograms. Alternatively, the powder bed 920 of the printed object including the example scene 900 may have a mass greater than 50 kilograms. Alternatively, the powder bed 920 of the printed object including the example scene 900 may have a mass greater than 100 kilograms. Alternatively, the powder bed 920 of the printed object including the example scene 900 may have a mass greater than 500 kilograms. Alternatively, the powder bed 920 of the printed object including the example scene 900 may have a mass greater than 1,000 kilograms. Alternatively, the powder bed 920 of the printed object including the example scene 900 may have a mass greater than 2,000 kilograms. Alternatively, the powder bed 920 of the printed object including the example scene 900 may have a mass greater than 5,000 kilograms. Alternatively, the powder bed 920 of the printed object including the example scene 900 may have a mass greater than 10,000 kilograms.

[0181] In some embodiments, build platform 930 of example scene 900 may have an area greater than 0.25 square meters, and powder bed 920 including a printed object of example scene 900 may have a mass greater than 10 kilograms.

[0182] Powder bed fusion technology processes powdered materials to form monolithic objects from metal, ceramic and plastic powders. Sufficient energy is required to bring the powder to the corresponding melting / sintering / alloying temperature or phase change temperature. If the powder material begins to approach its phase change temperature, less energy may be required to complete the phase change. Powder bed fusion additive manufacturing can benefit from preheating of the powder bed to reduce the amount of energy delivered by the laser or other energy source. This can allow the use of lower intensity lasers and less dwell time to bond the powder, thereby increasing productivity.

[0183] Some powder materials such as metals may require post-processing heat treatment to relieve stress concentrations and increase mechanical strength. Post-processing heat treatment may include controlled temperature annealing or rapid cooling to improve desired mechanical or electrical properties. Preheating and post-processing heat treatment of powders can be achieved by embedding heating / cooling elements / temperature sensors inside the walls of the build chamber / inside the build platform and using feedback algorithms to control the rate of heating / cooling. Heat losses can be reduced by using insulating materials inside the walls of the build chamber.

[0184] Reference Fig. 9B A thermal management system suitable for use with the powder bed and chamber is discussed. Fig. 9BAn example apparatus of a laser-based powder bed fusion additive manufacturing system 900B according to an embodiment of the present disclosure is shown. System 900B includes an energy source 950 and an energy beam steering system / driver 955 as part of a print head 910B. Optical mechanical components 930(1)-930(N) can distribute energy beams for print head 910B through system 900B. Processor 901 and memory 940 enable data input, monitoring, control, and feedback control using various sensors. These systems can include input of 3D object data 941, print head control 942, build platform control 943, optical mechanical component control 944, and build chamber control 945.

[0185] The laser-based powder bed fusion additive manufacturing system 900 may include one or more build chambers. For purposes of illustration and without limitation, Fig. 9B One or more build chambers of system 900 are shown as build chambers 920B(N), where N is a positive integer greater than or equal to 1. Build chambers 920B(1)-920B(N) may include powder dispensing units 922(1)-922(N) for dispensing powder material and build platforms 924(1)-924(N) for supporting a powder bed formed by the powder material. Each of build chambers 920B(1)-920B(N) may have different sizes and may be interchangeable with each other within powder bed fusion additive manufacturing system 900. Build chambers 920B(1)-920B(N) may have removable doors to facilitate removal of powder from one side of build chambers 920B(1)-920B(N) after building. During powder bed fusion additive manufacturing, build chambers 920B(1)-920B(N) may be sealed in an atmosphere. The atmosphere may include, but is not limited to, vacuum, air, nitrogen, argon, or helium.

[0186] In some embodiments, the walls / ceilings of build chambers 920B(1)-920B(N) may be embedded with heating / cooling elements 926(1)-926(N) and temperature sensors 928(1)-928(N) to control the thermal environment within build chambers 920B(1)-920B(N).

[0187] In some embodiments, heating / cooling elements 926(1)-926(N) may be fluid channels that enable heat exchange. The fluid may be heated or cooled outside of build chamber 920B(1)-920B(N) and exchange heat with the wall / ceiling by moving the fluid through the fluid channels. The fluid may include, but is not limited to, oil, water, steam, air, nitrogen, argon, or a coolant.

[0188] In some embodiments, heating / cooling elements 926 ( 1 )- 926 (N) may be resistive heating elements and thermionic cooling elements, respectively.

[0189] In some embodiments, temperature sensors 928(1)-928(N) may be thermocouples embedded within a wall / ceiling within build chambers 920(1)-920(N).

[0190] In some embodiments, temperature sensors 928(1)-928(N) may be infrared cameras mounted on the wall / ceiling within build chambers 920(1)-920(N).

[0191] In some embodiments, each of build chambers 920(1)-920(N) may include radiation shielding on the walls / ceiling of build chambers 920(1)-920(N) to reduce heat loss.

[0192] In some embodiments, build chambers 920(1)-920(N) may include low thermal conductivity materials as part of the walls / ceilings.

[0193] In some embodiments, each of build platforms 924(1)-924(N) may be capable of vertical movement or fixed at a given height during powder bed fusion additive manufacturing. Build platforms 924(1)-924(N) may have different sizes and support powder beds of different masses. Build platforms 924(1)-924(N) may be removable from build chambers 920(1)-920(N) on tracks, wheels, or other means.

[0194] Fig.10 Methods for minimizing powder volume requirements during a build operation are described. According to the present disclosure, process 1000 can be utilized to implement printing a variable print chamber wall for powder bed fusion in a powder bed fusion additive manufacturing system. At 1010, process 1000 can involve dispensing powder material to form a first layer of a powder bed on a support surface of a build platform.

[0195] At 1020, process 1000 may involve selectively melting a portion of a first layer of the powder bed to form one or more first walls from the melted portion of the first layer of the powder bed. The one or more first walls may accommodate another portion of the first layer of the powder bed on the build platform. In some embodiments, the one or more first walls may include multiple walls surrounding an area inside the build platform to create an area without powder material. At 1030, process 1000 may involve dispensing powder material to form a second layer of the powder bed on the first layer of the powder bed. At 1040, process 1000 may involve selectively melting a portion of the second layer of the powder bed to form one or more second walls from the melted portion of the second layer of the powder bed. The one or more second walls may accommodate another portion of the second layer of the powder bed.

[0196] In some embodiments, the one or more first walls may include a plurality of first walls surrounding another portion of the first layer of the powder bed above the first region of the build platform. In addition, the one or more second walls may include a plurality of second walls surrounding another portion of the second layer of the powder bed above a second region of the first layer of the powder bed, wherein the second region is smaller than the first region.

[0197] In some embodiments, the one or more first walls may include at least one wall along at least one of the multiple perimeters of the build platform. In addition, the remaining one or more perimeters of the multiple perimeters of the build platform may border one or more structural walls. In some embodiments, process 1000 may also involve causing relative movement between the build platform and the one or more structural walls in a direction perpendicular to the support surface of the build platform. In addition, process 1000 may involve distributing powder material on a first layer of the powder bed and one or more first walls to form a second layer of the powder bed. In addition, process 1000 may involve selectively melting a portion of the second layer of the powder bed to increase the height of the one or more first walls.

[0198] In another embodiment, the temporary wall can be manufactured to have a conduit, cavity, or porous portion (hereinafter referred to as a "fluid passage") that can support fluid flow. The fluid passage can be open or partially closed, and can be formed to connect to an external pipe, hose, sprayer or other fluid communication system. Air, nitrogen, water, high temperature or silicone oil or other suitable gas or liquid can be circulated or otherwise transferred through the fluid passage to improve thermal management. Thermal management can include rapid cooling or controlled cooling, and the fluid can be circulated (for example, through a conduit formed in the temporary wall), or sprayed, dripped or splashed onto, for example, a porous outer wall portion.

[0199] The proposed scheme can be implemented in a powder bed fusion additive manufacturing system for printing metal, plastic or ceramic parts. The application of the proposed scheme can be more specifically defined as being used in the print bed portion of the machine on the receiving end of the laser or electron beam. In various embodiments of the present disclosure, one or more energy sources of the print head of the powder bed fusion additive manufacturing system can be controlled to print the walls of the build chamber. This allows the edge walls of the chamber to be eliminated and can allow the creation of subset areas. The presence of subset areas / volumes / voids can help minimize the use of powder and enable the creation of powder-free volumes. This feature is particularly useful when processing expensive materials such as gold, silver and copper, and is also very useful for the processing of oversized objects, where excess powder can comprise a large portion of the standard print volume. According to the proposed scheme, powder can be selectively distributed throughout the build area in predetermined wall areas generated during the additive manufacturing process.

[0200] Since the print bed and print head are typically separated vertically for successive layers, the print chamber walls are needed to support the previously deposited layers of powder and the printed object. One example might involve protrusions to cling to the wall. Another example might involve printing a perimeter wall (and possibly structural support for it) during each layer. The wall might be cut and recycled after each print.

[0201] In some embodiments, most or all of the peripheral walls may be raised, and the walls may also be printed to reduce the powder bed area for the powder layer, while using a "bucket" formed by the peripheral walls to capture powder that falls outside the printed walls.

[0202] In some embodiments, the raised wall may not be a complete perimeter. For example, when first placing the print bed into the print station, and subsequently lifting the completed bed (powder and printed object), access points may be needed for a forklift or other material handling equipment. Printing of a limited wall in this area provides the remaining wall required to support the powder during the print cycle. The material handling equipment may then "punch through" the printed wall to gain access to the lifting points. In some embodiments, the lifting points may be determined by a priori algorithms or user placement, and built into the wall at strategic locations.

[0203] The printed wall does not need to match the geometry of the print bed, nor does it need to exactly match the wall printed in the previous layer. This can be done with appropriate powder dispensing equipment and logic to spread the powder between the wall areas sufficient to cover the area where powder is needed. Advantageously, this can save a lot of time, weight and / or powder per layer.

[0204] Fig.11AAn example scenario 1100 is shown in which a powder bed 1120 is formed on a build platform 1130 according to the present disclosure. The build platform 1130 may have an area of ​​0.25 square meters and may support a powder bed 1120 of powder material, which may be 0.5 meters deep inside the build chamber 1110. The scenario 1100 may be at the end or in the middle of a printing cycle. Below the build platform 1130 is a hopper 1140 with an inclined wall that may be 45-60 degrees relative to the horizontal surface on which the build platform 1130 is arranged. In some embodiments, the hopper 1140 may include an auger 1150.

[0205] Fig. 11B Another example scene 1101 is shown, depicting the separation of a powder bed 1121 from a build platform 1131. Scene 1101 may be at the end of a printing cycle or in the middle of a cycle that is aborted for various reasons. Inside the build chamber 1111, the build platform 1131 supporting the powder bed 1121 may be tilted more than 90 degrees from a horizontal position. The pull of gravity due to the weight of the powder bed 1121 causes the powder material and printed objects embedded in the powder bed 1121 to fall into the hopper 1141 below. The build chamber 1111 may include a vacuum 1160 and a high pressure jet 1162 so that most of the powder can be collected in the hopper 1141. After tilting the build platform 1131, suction 1160 and gas jet 1162 can be used to remove sticky powder remaining on the build platform 1131. The hopper 1141 may have tilted walls to help guide the powder onto the bottom of the hopper 1141. The hopper 1141 may include an auger 1151.

[0206] Processing may involve controlling a powder dispensing assembly to dispense multiple layers of powder material during a printing cycle to form a powder bed. The vertical motion of the powder dispensing assembly may be controlled to maintain a constant separation from the powder bed. After a portion of the dispensed powder layer is bonded together, the vertical motion causes the powder dispensing assembly to be indexed away from the powder bed (e.g., upward) by a distance equal to the thickness of the dispensed powder layer. In order to remove the residual powder, the movement of the build platform may include rotation, tilting, flipping, vibration, shaking and / or shaking. Due to these movements, the powder bed on the build platform may fall into the hopper below the build platform due to the weight of the powder bed. A vacuum system, a robotic arm and / or a gas atomizer may be used to further remove the remaining powder on the build platform. Therefore, most of the powdered material can be collected in the hopper for reuse or storage. In some embodiments, an auger and / or a conveyor can be used to transport the powder collected in the hopper toward one or more storage chambers. In another process embodiment, most of the powdered material can be sealed in an atmosphere suitable for the powdered material in one or more storage chambers. The atmosphere may include vacuum, air, nitrogen, argon, helium, other inert gases, or noble gases.

[0207] Fig. 12A and Fig. 12B A system for long part manufacturing is shown. Many current 3D printers have significant and frequent downtime when the build chamber must be emptied of powder and printed parts and reset for the next print job. In the following description, a unified coordinate system 1211 is defined. Therefore, certain systems may correspond to or define longitudinal directions 1211a, lateral directions (not shown), and transverse directions 1211c that are orthogonal to each other. The longitudinal direction 1211a may correspond to the long axis of the system. Therefore, during additive manufacturing, the long axis of the long part 1210 may be substantially aligned with the longitudinal direction 1211a. The lateral direction may be combined with the longitudinal direction 1211a to define a horizontal plane. That is, both the longitudinal direction and the lateral direction may extend within the horizontal plane. The transverse direction 1211c may extend up and down aligned with gravity.

[0208] In selected embodiments, systems and methods according to the present invention can enable or support substantially continuous additive manufacturing without such downtime. Fig. 12A and Fig. 12BAs can be seen, this can be accomplished by manufacturing part 1210 in segments. For example, the system can (1) manufacture a first segment of part 1210, (2) advance part 1210 a selected distance along a conveyor, (3) manufacture a second segment of part 1210, (4) advance part 1210 a selected distance along conveyor 1218, and (5) repeat until all segments of part 1210 have been completed. In practice, additive manufacturing and cleanup (e.g., separation and / or recovery of unused or unconsolidated particulate material) can be performed in parallel (i.e., simultaneously) at different locations or zones on the conveyor. Thus, additive manufacturing in accordance with the present invention need not be stopped to remove particulate material and / or parts.

[0209] The system may define or include a plurality of zones 1236a-1236c. Different tasks may be performed in different zones. In selected embodiments, the different zones may correspond to different locations along the conveyor. Accordingly, the conveyor may advance the part (e.g., translate in the direction indicated by arrow 1232) through the various zones of the system. In certain embodiments, the system may include three zones 1236a, 1236b, 1236c. The first zone 1236a may correspond to, include, or span a portion of the conveyor where additive manufacturing occurs. Thus, the first zone 1236a may correspond to an area on the conveyor where various layers of particulate material 144 are laid and the particulate material is held in close contact with the part.

[0210] The second zone 1236b may directly follow the first zone 1236a. The second zone 1236b may be characterized by the movement of the non-incorporated portion of the particulate material away from a significant portion of the part. For example, in the second zone 1236b, one or more walls may terminate or be removed so that the unincorporated portion of the particulate material may no longer be completely contained in the lateral direction. As a result, some of the unincorporated portion of the particulate material may overflow the sides of one or more plates, conveyors, etc. The overflowed particulate material may fall into one or more containers where it may be collected and reused.

[0211] The third zone 1236c may directly follow the second zone 1236b. The third zone 1236c may be characterized in that a portion of the part 1210 within the third zone 1236c is exposed to view (e.g., completely, substantially, or partially exposed to view by removing or moving a significant portion of the unincorporated portion of the particulate material), while the part 1210 does not change its position in the lateral direction and the transverse direction 1211c.

[0212] For example, in certain embodiments, the front of the part 1210 may reach the third zone 1236c while the tail of the part 1210 is still being manufactured in the first zone 1236a. Thus, in selected embodiments, the conveyor, one or more plates, one or more temporary supports 1223, one or more walls, or the like, or combinations or sub-combinations thereof, may cooperate to maintain the front of the part 1210 in the same position in the lateral and transverse directions 1211c as the front occupied in the first zone 1236a and the second zone 1236b. Thus, the position of the front of the part 1210 does not excessively interfere with, distort, etc., the additive manufacturing occurring on the tail of the part 1210 in the first zone 1236a.

[0213] In selected embodiments, all of the unconsolidated portion of the particulate material outside of the part 1210 may be removed in the second zone 1236b or in some combination of the second zone 1236b and the third zone 1236c. However, in certain alternative embodiments, the bed may be removed from the conveyor while the four walls remain intact. Thus, all or some of the remaining unconsolidated portion of the particulate material may be removed at a station spaced a distance from the first zone 1236a.

[0214] In another embodiment, a ramp can be used to transition from a lower segment or zone to a subsequent higher segment or zone. For example, a ramp can enable a back wall corresponding to a lower segment to be built higher than a majority of the lower segment through an additive manufacturing process, so that the back wall can become the front wall of a subsequent higher segment. When only the back wall is built, building a ramp is much faster than laying down a complete layer (e.g., a layer covering the entire lower segment).

[0215] The ramp can include multiple layers of granular material whose lengths along one or more directions (e.g., longitudinal direction 1211a) vary incrementally. For example, within the ramp, the length of each successive layer can be shorter than the immediately preceding layer. The angle of the resulting ramp relative to the horizontal plane can be less than the critical angle of repose of the granular material. Therefore, the granular material forming the ramp can be stable and will not fall off or move due to the gravitational acceleration acting thereon.

[0216] In operation, a first layer of particles of a granular material may be distributed and radiant energy may be directed toward all particles within the first layer that form a portion of a selected particle. A second layer of particles of a granular material may be distributed on top of the first layer and radiant energy may be directed toward all particles within the second layer that form a portion of a selected particle. The first layer may define a first plane and the second layer may define a second plane that is parallel to the first plane. In some embodiments, the first plane and the second plane are both horizontal planes. In other embodiments, the first plane and the second plane both extend at an angle relative to a horizontal plane that is greater than zero and less than or equal to a critical angle of repose of the granular material, thereby forming a slope.

[0217] Fig.13A An additive manufacturing system 1300 is shown including a powder chamber 1302 having a powder bed 1304. The system 1300 may also include a processing platform 1320, which may be a designated processing area, another powder chamber, a coating station, a conveyor, a shipping container, or any other desired manufacturing system component. The system 1300 also includes a robotic arm 1310 having a manipulator 1312 capable of grasping a part 1330 by its additively manufactured manipulation points 1332. A sensor system 1334 may be mounted on the robotic arm 1310, or alternatively, on, in, or near the powder chamber 1302.

[0218] Although the six-degree-of-freedom single robot arm with a gripper is the manipulation device shown in the figure, other automation, mechanical or manual embodiments can be adopted.For example, a crane, a lift, a hydraulic arm, a fixture, a track or rail, a locking mechanism or any other type of manual or automatically controllable manipulation device can be used.The manipulation device can be installed beside, above, near or inside the powder chamber 1302.Or, the operating device can be movably installed above the powder chamber, near or positioned on the rail in the powder chamber.A plurality of manipulation devices can be used in certain embodiments.

[0219] The manipulator may include a position, depth, laser scanning or similar sensor system 1314. The sensor may be mounted on or near the manipulator, elsewhere on the robotic arm, or on, near or within the powder chamber or processing platform 1320. In some embodiments, the sensor may be movable, having a hinge, track, hydraulic piston or other suitable actuation mechanism for rotating, raising, depressing, oscillating or laterally scanning the sensor. In some embodiments, a conventional RGB CMOS or CCD sensor may be used alone or in combination with a specialized depth sensor or optical edge tracking sensing system. Embodiments may be selected to improve 3D positioning of parts, including identification and use of guides, markers or other detectable positioning markers.

[0220] Fig. 13B Illustration about Fig.13A 1 and 13. The system is depicted in which a robotic arm 1310 lifts and reorients a part 1330 by one of its additive manufacturing manipulation points 1332. In some embodiments, the part 1330 can be lifted, rotated, linearly translated, and returned to the powder bed 1304 for further processing.

[0221] Fig. 13C Illustration about Fig.13A1 and 13. The system depicted in FIG. 1 shows a system in which a robotic arm 1310 lifts and reorients a part 1330 by one of its additive manufacturing manipulation points 1332. In this embodiment, the part 1330 is lifted, rotated, and placed onto a processing platform 1320 for further processing.

[0222] Fig.14 Part 1400 including various possible additively manufactured robotic manipulation points is shown. Part 1400 supports various protruding structures (i.e., 1402, 1404, 1406, 1408, and 1414) and internal structures or cavities (i.e., 1410, 1412, and 1416) that can act as robotic manipulation points. In this figure, structure 1402 is a crescent tab with two narrow connection points to part 1400. The tab portion allows for easy engagement with a manipulator having a clamping or pinching gripper, while the narrow connection points simplify removal of structure 1402 by mechanical cutting, sawing, punching, or drilling, or by a directed energy beam. Similarly, pin 1404 is a small protruding structure that can be engaged by a clamping or pinching gripper or by a "position" holding type engagement system that surrounds and contracts to hold pin 1402. The rectangular tab 1406 is attached at a single narrow point, allowing some embodiments of the manipulator to twist and break free the tab after the part has been moved to the desired area / position. The plate 1408, again attached at two points to simplify subsequent removal by mechanical clipping or energy beam, is relatively long and wide to simplify engagement by the manipulator.

[0223] The additive manufacturing of part 1400 can be designed to include recesses, platforms, cavities, holes, or other internally defined structures that do not significantly affect the function of the part but improve the reliability of engagement with the robotic arm. For example, a prismatic locking cavity 1410 can guide a pin or clamping system to engage with the cavity. Alternatively, a deployment clamp can be used to engage a recess 1412 defined in part 1400. If desired, a cavity or opening 1416 can also be defined in a removable protruding tab 1414. In some embodiments, a cavity or opening in a substantially additively manufactured part can be defined by subtractive machining, drilling, stamping, or removing etched material or a directed energy beam. In certain other embodiments, after use, the cavity can be filled using additive manufacturing techniques by using a thermosetting plastic or any other suitable filling technique.

[0224] In some embodiments, the two-dimensional or three-dimensional positioning of the part 1400 can be improved by using imaging or other optical sensors that use the protruding tabs or cavity locations to identify the precise location of the part. In other embodiments, the marking light guide or marking 1420 can be additively formed or mechanically or laser engraved on the protruding structure or the part itself to improve the guidance of the 3D positioning of the joint after movement.

[0225] In one embodiment, processing can be performed by the following steps. In a first step, material is placed on a powder bed in a powder chamber. Then, a part including one or more manipulation points is manufactured using a directed beam of two-dimensional patterned energy. A manipulator can engage the manipulation points and lift the part off the powder bed. The part can be repositioned on the powder bed for further processing or, optionally, moved to a new processing area away from the powder bed and chamber. In an optional step, the manipulation points can be removed (e.g., protruding tabs are mechanically trimmed) or filled (e.g., additively defined holes or cavities filled with epoxy).

[0226] Fig.15An example process 1500 for collecting and characterizing powder samples of powder materials during a printing process is shown. The process 1500 can be used to collect powder samples from a powder bed or a powder dispensing assembly, and characterize the powder samples in real time in a test kit according to the present disclosure. At 1510, the process 1500 may involve controlling a collector during a printing cycle to collect multiple powder samples of powder materials when forming a printed object. The powder material may include metal, ceramic, plastic powder, or other suitable powders that can be bonded together when subjected to thermal energy. The collector may collect powder samples periodically at predetermined intervals or randomly or at predetermined stages during the printing process. For example, powder samples may be collected every 10 minutes, or only when 1 / 5 and 4 / 5 of the printing process are completed. The collector may have a mechanism for transferring powder from a powder bed or a powder dispensing assembly. Depending on how many tests are required for analysis, the collector may also control the amount of powder transfer. At 1520, the process 1500 may involve controlling the test kit to perform one or more tests of the test. In some embodiments, one or more specific properties of the powder material may need to be strictly controlled within a certain range to ensure the mechanical, electrical or optical properties of the printed object. In other embodiments, for audit purposes, it may be necessary to retain the characteristics of the powder during the printing process. The test kit may include an instrument capable of performing one or more tests. For illustrative purposes and without limitation, one test may measure the distribution of powder sizes by a particle size analyzer; a second test may measure the density of a powder sample by a specific gravity meter; and a third test may identify substances within a powder sample by gas chromatography mass spectrometry. At 1530, process 1500 may involve determining whether to modify a set of printing parameters for the printing process or whether to abort the printing process based on the result characteristics from the test. The determination may include computer simulation based on a set of models using the results of the characterization as input. Powder samples that are not certified or have insufficient processing conditions may experience undesirable powder changes. The test may provide real-time feedback on the properties of the powder during the printing process. One or more printing parameters may be modified based on the test results. For example, when a gas specific gravity meter measures a deviation in a specific powder density that may affect the energy per unit volume required to melt or sinter the powder, the incident beam intensity may be increased or decreased. The dwell time of the incident beam provided by the print head or the thickness of the powder layer dispensed by the powder dispensing assembly may also be controlled to adjust for changes in energy requirements. If the energy per unit volume deviates too much from the specified powder density, the printing process may stop or abort because the energy source inside the print head may not meet the requirements for powder melting. In another example, contamination within the powder sample can be detected by gas chromatography mass spectrometry, which may affect one or more electrical, mechanical and optical properties of the printed object.In other embodiments, if the characterization results indicate the use of unlicensed powders or hazardous powders (including unlicensed powders that may result in poor additive manufacturing results), the printing process can be stopped.

[0227] In some embodiments, prediction of the final print quality based on the results of in-process (real-time or in-situ) characterization of a powder sample can be performed by simulation using a set of models. For example, the size control of the printed object can rely on the resolution of the incident beam and the temperature gradient of the powder at the boundary of the melting area. If the temperature does not drop fast enough at the boundary and causes the tolerance of the dimensional requirement to be exceeded, the melted area may extend beyond the expected boundary. The temperature gradient can be simulated by a heat transfer model that calculates the thermal conductivity based on the properties of the powder (e.g., based on the composition and size of the powder). If the size of the printed object predicted by the simulation model exceeds the tolerance of the dimensional requirement, the printing process can be aborted.

[0228] At 1540, process 5100 may involve storing the powder samples in a plurality of sample cans. The sample cans may be stored for analysis that may not be suitable for in-process characterization, or for later audit purposes. The storage containers may be capable of packaging the powder samples under an atmosphere substantially identical to the in-process (real-time or in-situ) atmosphere inside the sample cans. The atmosphere may be a vacuum, air, or an inert gas such as nitrogen, carbon dioxide, argon, helium, or other noble gases.

[0229] refer to Fig.16 , a manufacturing facility 1624 according to the present invention may include one or more machines 1610 housed within an enclosure 1626. Such an enclosure 1626 may control one or more environmental conditions as desired or necessary. For example, the enclosure 1626 may protect the printed or to-be-printed material from undesirable thermal, chemical, photon, radiation, or electronic reactions or interactions, etc., or combinations or sub-combinations thereof. The enclosure 1626 may also protect a human operator or other nearby personnel from potentially harmful aspects of the machine and machine powder 1610, such as heat, ultraviolet light, chemical reactions, radioactive decay products, and laser exposure.

[0230] The one or more machines 1610 contained within a particular housing 1626 may all be of the same size or of different sizes. Similarly, the one or more machines 1610 contained within a particular housing 1626 may all be of the same type or of different types. For example, in selected embodiments, each of the one or more machines 1610 within the housing 1626 may combine (e.g., combine, bond, melt, sinter, melt, etc.) a particular particulate material in a batch process. In other embodiments, each of the one or more machines 1610 within the housing 1626 may combine a particular particulate material in a continuous process. In other embodiments, one or more machines 1610 within the housing 1626 may combine a particular particulate material in a batch process, while one or more other machines 1610 within the housing 1626 may combine a particular particulate material in a continuous process.

[0231] In certain embodiments, the manufacturing facility 1624 may include one or more airlocks 1628 forming one or more antechambers for the respective enclosures 1626. The airlocks 1628 may enable parts, materials 144, personnel, etc. to enter and exit the enclosures 1626 without compromising the environment (e.g., low oxygen and inert gas environments) within the enclosures 1626. The airlocks 1628 may include at least two airtight (or substantially airtight) doors 1630a, 1630b. The first door 1630a of the airlock 1628 may enable parts, materials 144, personnel, etc. to pass between the interior of the airlock 1628 and the interior of the respective enclosures 1626. The second door 1630b may enable parts, materials 144, personnel, etc. to pass between the interior of the airlock 1628 and the external environment surrounding the respective enclosures 1626. The airlock 1628 may also include a gas exchange system (not shown) that can clean and / or vent the airlock 1628 as needed or necessary, thereby effectively transitioning the gas environment within the airlock 1628 between a state that is compatible with the interior of the housing 1626 and a state that is compatible with the environment outside the housing 1626.

[0232] One or more machines 1610 may be arranged in enclosure 1626 such that sufficient space around machine 1610 is reserved for one or more human workers, robots, etc. to access machine 1610, remove parts therefrom, vacuum clean unconsolidated particulate material 144 for reuse, etc. Alternatively or additionally, enclosure 1626 may include various racks, construction walkways, etc. that enable one or more human workers, robots, etc. to access machine 1610 from above (e.g., visual access, physical access). This may be helpful when enclosure 1626 contains one or more large machines 1610, where access from the edges or sides thereof may not be sufficient to perform certain tasks.

[0233] In certain embodiments, manufacturing facility 1624 may include one or more gas management systems 1632 that control the composition of gaseous substances within enclosure 1626. Gas management system 1632 may maintain the concentration of an inert or substantially inert gas (e.g., vacuum, nitrogen, argon, carbon dioxide, etc., or combinations or subcombinations thereof) above a desired level (e.g., argon at or above about 99.9% by volume). Alternatively, or in addition, the gas management system may maintain the concentration of oxygen and / or water vapor below atmospheric levels. For example, in one embodiment, the desired level of gaseous oxygen by volume may be less than 0.05%, and water vapor by volume may be less than 0.05%.

[0234] The gaseous environment within the enclosure 1626 may be incompatible with the respiratory requirements of one or more individuals who may need to enter and / or work within the enclosure 1626. Therefore, in order to work within certain enclosures 1626 according to the present invention, one or more workers may wear personal protective equipment (PPE). Thereafter, when the worker enters the enclosure 1626, the PPE may create a barrier between the worker within the enclosure 1626 and the work environment.

[0235] In selected embodiments, the PPE worn by one or more workers may include a self-contained breathing apparatus (SCBA). The SCBA may be a closed-circuit device (e.g., a respirator) that filters, replenishes, and recycles or stores exhaled gases. Alternatively, the SCBA may be an open-circuit device that discharges at least some exhaled gases (e.g., nitrogen, carbon dioxide, oxygen, water vapor, or a combination or subcombination thereof) into the surrounding environment. In embodiments using an open-circuit device, the amount exhaled by one or more workers within the housing 1626 may be very small relative to the oversize of the housing 1626. Therefore, the release of oxygen, water vapor, etc., to the interior of the housing 1626 may be small enough to be negligible or at least within acceptable limits (e.g., within the rectification capacity of the gas management system 1632).

[0236] refer to Fig.17In selected embodiments, a manufacturing facility may include a plurality of work areas 1724 connected by one or more interface mechanisms 1728 to form a network 1740. One or more work areas 1724 forming such a network 1740 may be contained within a housing 1726. One or more work areas 1724 forming such a network 1740 may not require a housing 1726 and therefore may not be contained within one housing. One or more work areas 1724 forming such a network 1740 may be contained within one or more buildings. For example, in selected embodiments, all of the various work areas 1724 forming a network 1740 may be contained within a single building. In such embodiments, any work area 1724 contained within a housing 1726 may be a work area 1724 that requires more environmental conditioning than that provided by the building.

[0237] The various work areas 1724 of the network 1740 may be defined and / or arranged to correspond to certain manufacturing-related processes. Such processes may include creating a part by additive manufacturing; removing a part from a machine that created the part; removing unincorporated particulate material; separating a part from a base or bed, one or more support structures (e.g., an outer portion of one or more travel walls extending through the part, printed to support the part during additive manufacturing, one or more temporary structures that will not be included in the finished part, etc.); heat treating; shot peening; powder coating, painting, anodizing, etc.; packaging for shipping; or the like or combinations or sub-combinations thereof.

[0238] For example, in a selected embodiment, network 1740 may include a first working area 1724a for performing powder bed fusion in an inert environment provided by housing 1726, a second working area 1724b for removing particulate material 144 from build platform 146 in housing 1726, a third working area 1724c for shot peening to improve surface finish in housing 1726, a fourth working area 1724d for heat treating to anneal metal parts in housing 1726, a fifth working area 1724e for removing parts from build platform 146 in housing 1726, a sixth working area 1724f for packaging and shipping, and the like, or a combination or sub-combination thereof.

[0239] In the first working area 1724a, one or more machines may be contained within the housing 1726. These machines may all be of the same size or of different sizes. Similarly, these one or more machines may all be of the same type or of different types. For example, in the selected embodiment, each of the one or more machines within the housing 1726 may combine (e.g., combine, bond, melt, sinter, melt, etc.) a specific granular material in a batch process. In other embodiments, each of the one or more machines within the housing may combine a specific granular material in a continuous process. In other embodiments, one or more machines within the housing may combine a specific granular material in a batch process, while one or more other machines within the housing may combine a specific granular material in a continuous process.

[0240] One or more machines in the first work area 1724a can be arranged so that sufficient space around the machine is reserved for one or more human workers, robots, etc. to access the machine, remove parts therefrom, vacuum remove unconsolidated particulate material for reuse, etc. Alternatively or additionally, the first work area 1724a can include various racks, construction walkways, etc. that enable one or more human workers, robots, etc. to access the machine from above (e.g., visual access, physical access). This can be helpful when the first work area 1724a includes one or more large machines, where access from the edges or sides thereof may not be sufficient to perform certain tasks.

[0241] In the second working area 1724b, unmerged particulate material can be removed from the build platform by various methods. For example, a vacuum mechanism with a manually or robotically controlled (e.g., moved) collection port can be used to collect unmerged particulate material from around a part, off a build platform or bed, etc. Alternatively or in addition, one or more manually or robotically controlled (e.g., aimed) streams of pressurized gas can be used to remove unmerged particulate material from certain cracks, sweep unmerged particulate material from a build platform or bed, and / or move unmerged particulate material to one or more locations accessible by a vacuum.

[0242] In selected embodiments, as shown, the first work area 1724a and the second work area 1724b can be contained within separate housings 1726. In other embodiments, the first work area 1724a and the second work area 1724b can be contained within the same housing 1726. Furthermore, in certain embodiments, the first work area 1724a and the second work area 1724b can overlap geographically to at least some extent, but can be separated in time (e.g., one or more tasks corresponding to one work area 1724a can be performed at a different time than one or more tasks corresponding to another work area 1724b).

[0243] Alternatively, the first and second work areas 1724a, 1724b may be geographically adjacent to each other, but may overlap in time to some extent (e.g., one or more tasks corresponding to one work area 1724a may be performed at the same time as one or more tasks corresponding to another work area 1724b). In such an embodiment, the first zone of the machine may correspond to or may be the first work area 1724a, and the second zone (or a combination of the second and third zones) may correspond to or be the second work area 1724b.

[0244] In the third work area 1724c, the shot peening process can be applied to one or more parts manually or robotically. For example, in selected embodiments, the manual or robotic system can use the same particle material as the impact media in the shot peening process (i.e., the same particle material used to create the part) to improve the surface finish of the part.

[0245] In the fourth working area 1724d, the housing 1726 can be or include an oven for heat treating one or more parts. Thus, such a housing 1726 can be configured to generate, maintain and control a large amount of heat. The exact amount of heat can vary between the size of the housing 1726, the nature of the parts being heat treated, etc.

[0246] In the fifth work area 1724e, one or more build platforms or beds can be separated from the parts they support, one or more external portions of one or more travel walls extending through the part can be removed, one or more temporary structures printed to support the part during additive manufacturing that will not be included in the finished part can be removed, etc. or a combination thereof. In selected embodiments, this may involve a wire electrical discharge machining (EDM) process. In such an embodiment, the part can be immersed in a bath of partially deionized water, where the ion content is carefully controlled as part of the EDM process. The enclosure for the fifth work area 1724e can be included or omitted as desired or necessary.

[0247] In the sixth work area 1724f, one or more parts may be prepared for shipment and / or shipped. For example, in the sixth work area 1724f, one or more parts may be painted, packaged, wrapped in plastic, secured to one or more pallets, etc., and loaded onto a truck for shipment. A housing for the sixth work area 1724f may be included or omitted as desired or necessary.

[0248] In selected embodiments, the network 1740 may include a plurality of work areas 1724 connected in series by one or more interface mechanisms 1728. Such interface mechanisms 1728 may enable one or more parts to flow smoothly and efficiently from one work area 1724 to the next. Accordingly, the work areas 1724 may be arranged in the network 1740 so that the tasks associated therewith may be performed in a required or desired order.

[0249] Any of the enclosures may maintain a concentration of an inert or substantially inert gas (e.g., vacuum, nitrogen, argon, carbon dioxide, etc., or combinations or subcombinations thereof) above a desired level (e.g., argon at or above about 99.9% by volume). Alternatively or in addition, the enclosure may maintain a concentration of oxygen and / or water vapor below atmospheric levels (e.g., less than 0.05% by volume of gaseous oxygen and less than 0.05% by volume of water vapor).

[0250] The print bed, parts or other materials can be transported using a vehicle via an interface mechanism 1728 by rolling or otherwise moving on a path (e.g., a concrete floor), a conveyor system, a track, or a combination of multiple tracks using traditional railway concepts, linear motion on a track using an encoder, linear motion provided by a pulley system, motion and / or suspension provided by a magnetic levitation track, motion via a conveyor system or conveyor belt, etc. or a combination or sub-combination thereof. Large parts weighing 2,000 kg or more can be transported. The vehicle may have wheels that roll on a support surface. The support surface can be a floor (e.g., a floor with a visual, electronic or magnetically detectable path applied to it or embedded therein). The support surface can also be one or more tracks. Such tracks can be located below the parts carried by the vehicle. Alternatively, these tracks can be located above the parts carried by the vehicle. That is, the tracks can be elevated tracks, and the vehicle can be a cart or trolley that rolls on the elevated track while suspending the parts below it.

[0251] Wheeled or other vehicles may be controlled and / or operated manually, automatically, autonomously, or semi-autonomously. For example, in selected embodiments, one or more wheeled vehicles may be propelled and / or steered by one or more human operators. In other embodiments, various on-board or off-board control systems may sense what is happening with the vehicle and instruct the vehicle when to move, when to stop, how to steer, etc.

[0252] Many modifications and other embodiments of the present invention will occur to those skilled in the art having benefit of the teachings presented in the foregoing description and the associated drawings. Therefore, it should be understood that the scope of the present invention is not limited to the specific examples of the disclosed embodiments, and modifications and embodiments are intended to be included within the scope of the appended claims. It should also be understood that other embodiments of the present invention may be implemented without the elements / steps specifically disclosed herein.

Claims

1. An additive manufacturing method, comprising: Provide powder material; providing an energy source capable of generating the energy beam; directing the energy beam from the energy source toward an energy beam patterning unit to form a two-dimensional patterned energy beam; directing the two-dimensional patterned energy beam toward the powder material to form a part having manipulation points, the manipulation points being cavity structures defined within the part that can be filled by additive manufacturing; imprinting an optical mark on the part; as well as The part is moved using a manipulation device gripping the manipulation point, wherein the optical mark is used by an optical sensor to guide the manipulation device into engagement with the manipulation point, and wherein moving the part includes reorienting the part using the manipulation device before adding more powder material.

2. The additive manufacturing method according to claim 1, further comprising the following steps: restricting, by means of an enclosure, the exchange of gaseous matter between an interior of the enclosure and an exterior of the enclosure; identifying a plurality of machines positioned within the housing; performing, by each of the plurality of machines, a separate process of additive manufacturing including directing a patterned energy beam at a powder bed; as well as During the execution, gaseous oxygen within the enclosure is maintained below atmospheric levels by a gas management system.

3. The additive manufacturing method according to claim 1, further comprising the following steps: Creating a part by a machine contained within the housing, wherein the part has a weight greater than or equal to 2000 kilograms; During said creation, maintaining gaseous oxygen within said enclosure below atmospheric levels via a gas management system; As the airlock operates to provide a buffer between the gas environment within the enclosure and the gas environment outside the enclosure, transporting the part from inside the enclosure through the airlock to a location outside both the enclosure and the airlock; and During the transport, the weight of the parts is continuously supported.

4. The additive manufacturing method according to claim 1, wherein: At least one other of the handling points protrudes from the part and has a narrow connection point to the part that can be removed by a directed energy beam.

5. The additive manufacturing method according to claim 1, wherein: The optical marking is inscribed by laser.

6. The additive manufacturing method according to claim 1, wherein: The optical mark is mechanically inscribed.

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