Additive manufacturing system and method

Abstract

The invention relates to additive manufacturing systems and methods. Additive manufacturing systems including two-dimensional energy patterning systems for imaging a powder bed are disclosed. Improved optical systems are described that support beam combining, beam steering, and patterning and unpatterning beam recycling and reuse.

Description

[0001] This application is a divisional application of the application filed on October 27, 2016, with application number 202310615890.6 and entitled "Additive Manufacturing System and Method".

[0002] The application filed on October 27, 2016, with application number 202310615890.6 and entitled "Additive Manufacturing System and Method", is a divisional application of the application filed on October 27, 2016, with application number 202110789550.6 and entitled "Additive Manufacturing System and Method".

[0003] The application filed on October 27, 2016, with application number 202110789550.6 and entitled "Additive Manufacturing System and Method", is a divisional application of the application filed on October 27, 2016, with application number 201680067983.8 and entitled "Additive Manufacturing System and Method". Cross-referencing of related patent applications

[0004] This disclosure is part of a non-provisional patent application that claims priority to the following applications: U.S. Patent Application No. 62 / 248,758, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,765, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,770, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,776, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,783, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,791, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,799, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,966, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,968, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,969, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,980, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,989, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,780, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,787, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,795, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,821, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,829, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,833, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,835, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,839, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,841, filed on October 30, 2015, U.S. Patent Application No. 62 / 248,847, filed on October 30, 2015, and U.S. Patent Application No. 62 / 248,848, filed on October 30, 2015, is incorporated herein by reference in its entirety. Technical Field

[0005] This disclosure generally relates to systems and methods for additive manufacturing. In one embodiment, powder bed melting manufacturing with two-dimensional energy patterning and energy beam reuse is described. background

[0006] Traditional part manufacturing typically relies on removing material through drilling, cutting, or grinding to form parts. In contrast, additive manufacturing (also known as 3D printing) usually involves building parts by sequentially adding material layer by layer. Starting with a 3D computer model, additive manufacturing systems can be used to create complex parts from a wide variety of materials.

[0007] An additive manufacturing technique called powder bed fusion (PBF) uses one or more focused energy sources (such as lasers or electron beams) to pattern in a thin layer of powder by melting the powder and bonding it to the underlying layer. The powder can be plastic, metal, or ceramic. This technique is highly precise, typically achieving feature sizes as small as 150-300 micrometers. However, powder bed fusion additive manufacturing machine manufacturers strive to create machines capable of producing over 1 kg / hr of printing material. Due to the slow powder-to-solid conversion rate, machine size is relatively small due to the length of time required to print larger parts. The largest machines today typically have printable part volumes of less than 64 L (40 cm²). 3 Although these printers can print parts in almost any geometry, their high machine cost and low powder conversion rate result in very high amortization costs, leading to expensive parts.

[0008] Unfortunately, simply scaling up the machine to increase part size or reduce manufacturing costs is not an acceptable solution. At a minimum, to melt a given volume of material, the laser must provide sufficient energy to reach the melting temperature and provide the phase transition energy required for melting. If there is no heat dissipation in this process, then 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 the laser power. Unfortunately, increases in laser power are proportional to increases in laser cost, and scaling up significantly increases the cost of machines that are already expensive today.

[0009] Even if laser cost isn't a factor, scaling laser power has other adverse effects. Each powdered material has optimal melting properties, which depend on the power flux. If the power is too low, the powder won't melt; if it's too high, the laser will drill into the material (key-holing). Increasing the laser power of a machine already operating at one of these optimal points necessitates increasing the laser area (spot size) to maintain the optimal power flux. Simply increasing the spot size reduces printable resolution, while splitting the laser into multiple beams increases system complexity.

[0010] In reality, currently available powder bed additive manufacturing machines may be limited by part size, part manufacturing cost, part detail resolution, and part manufacturing output. Summary of the Invention

[0011] This application provides the following: 1) A beam assembly system for additive manufacturing, comprising: A first laser emits a beam of light at a first wavelength; A second laser emits a beam at a second wavelength different from the first wavelength; A beamforming optics device that forms a single beam, the beamforming optics device including at least one wavelength filter to allow light of a first wavelength to pass through and reflect light of a second wavelength in a common beam; and A light patterning unit is used to receive the common beam and form a two-dimensional patterned beam.

[0012] 2) According to the beam combining system described in 1), the beamforming optics further includes a transmission optics.

[0013] 3) The beam combining system according to 1), wherein the beamforming optics further includes at least one of a reflective optics and a diffractive optics.

[0014] 4) According to the beam combining system of 1), wherein the beamforming optics further includes three or more lasers and combines light of at least three wavelengths.

[0015] 5) An additive manufacturing system, comprising: A high-energy photon source to generate a beam; A reflective patterning unit, which receives the beam and reflects the two-dimensional patterned beam; and An image repeater is used to receive the two-dimensional patterned beam and focus it as a two-dimensional image onto a powder bed.

[0016] 6) The additive manufacturing system according to 5), wherein the reflective patterning unit is optically addressed.

[0017] 7) The additive manufacturing system according to 5), wherein the high-energy photon source further includes a plurality of semiconductor lasers.

[0018] 8) The additive manufacturing system according to 5), wherein the reflected light patterning unit further includes a high transmittance layer, a twisted nematic (TN) liquid crystal layer and a photoconductor layer.

[0019] 9) The additive manufacturing system according to 5), wherein the reflective patterning unit is cooled.

[0020] 10) An additive manufacturing apparatus, comprising: A first optical component is configured to receive a plurality of light beams, comprising at least one or more light beams, from one or more light sources, and the first optical component is further configured to multiplex the plurality of light beams. An optical device configured to reshape and mix the plurality of light beams to provide a first light beam; A spatial polarization valve configured to apply a spatial polarization pattern to a first beam to provide a second beam that can be directed toward a powder bed, wherein the spatial polarization valve is optically addressable to form a two-dimensional pattern; A polarizer configured to separate the polarization state of the second beam to reflect the third beam; and A second optical component is configured to reshape the third beam into a fourth beam by rotating its polarization state to that of the first beam. The second optical component is also configured to guide the fourth beam as one of the plurality of beams to the first optical component to generate a fifth beam that passes through the polarizer and is not reflected by the polarizer.

[0021] 11) An additive manufacturing method, comprising: One or more light beams are emitted, each of which is polarized; Each of two or more beams is split into two separate beams, each of the two separate beams corresponding to a majority polarization state or a minority polarization state, respectively; Spatially stacking the separated beams corresponding to the majority polarization states of each of the two or more beams to provide a first beam corresponding to the majority polarization states; Spatially stacking the separated beams of each of the two or more beams corresponding to the minority polarization states to provide a second beam corresponding to the minority polarization states; Apply a plurality of polarization patterns to the first beam; A few polarization patterns are applied to the second beam; Combine patterned first and second beams to provide a single beam; and The single beam is guided to the powder bed.

[0022] 12) An apparatus comprising: Multiple lens assemblies, including interchangeable portions, are configured to provide multiple magnifications that proportionally increase or decrease the size of the image of the incident light; and A mechanical component capable of selecting one of the lens assemblies to provide one of the magnifications, so as to convert a first image of the incident light into a second image of the incident light according to the one of the magnifications.

[0023] 13) The apparatus according to 1) further includes: Build platform racks; and The final beam-directing device, mounted on the build platform frame, is capable of guiding the incident light emitted from one or more of the lens assemblies, such that a second image of the light is formed in a position holding a powder bed of powdered material, which is supported by the build platform frame.

[0024] 14) A method for a 3D printing job, comprising: During a 3D printing job, information is obtained regarding the intensity of incident light at a position relative to the top surface of the powder bed and the magnification and image distance in relation to the pixel size. One of a plurality of lens assemblies is configured to provide incident light having the magnification, wherein the lens assembly includes a plurality of first group optical lenses and a plurality of second group optical lenses, and wherein the second group optical lenses are interchangeable from the lens assembly; Multiple rotations are performed on one or more sets of mirrors mounted on one or more sets of compensation frames and on a final set of mirrors mounted on the build platform frame to guide the incident light from the precursor image to a position on the final image plane on the top surface of the powder bed; and Multiple translational movements are performed on the construction platform frame and the one or more sets of compensation frames to control the distance of the incident light from the initial image position to the position on the top surface of the powder bed, so as to maintain the image resolution substantially at the desired position.

[0025] 15) An additive manufacturing system, comprising: Energy beam; An optically addressable optical patterning unit is used to receive the energy beam and emit light as a two-dimensional patterned beam, wherein the optically addressable optical patterning unit rejects energy not required to form the two-dimensional patterned beam; An image repeater for receiving the two-dimensional patterned beam and focusing it as a two-dimensional image onto a powder bed; and The energy processing unit that rejects the energy reuses the rejected energy.

[0026] 16) The additive manufacturing system according to 15), wherein the energy beam is light.

[0027] 17) The additive manufacturing system according to 15), wherein the rejected energy is repatterned and directed to align with the powder bed.

[0028] 18) The additive manufacturing system according to 15), wherein the energy beam is light, and the additive manufacturing system further includes... A first laser emits a beam of light at a first wavelength; A second laser emits a beam at a second wavelength different from the first wavelength; A beamforming optics device that forms a single beam, the beamforming optics device including at least one wavelength filter to allow light of a first wavelength to pass through and reflect light of a second wavelength in a common beam; and A light patterning unit is used to receive the common beam and form a two-dimensional patterned beam.

[0029] 19) The additive manufacturing system according to 15), wherein the optically addressable light patterning unit reflects the light to form the two-dimensional patterned beam.

[0030] 20) The additive manufacturing system according to 15), wherein the energy beam is light, and the additive manufacturing system further includes: A first optical component is configured to receive a plurality of light beams, comprising at least one or more light beams, from one or more light sources, and the first optical component is further configured to multiplex the plurality of light beams. An optical device configured to reshape and mix the plurality of light beams to provide a first light beam; An optical patterning unit includes a spatial polarization valve configured to apply a spatial polarization pattern to a first beam to provide a second beam that can be directed toward a powder bed, wherein the spatial polarization valve is optically addressable to form a two-dimensional pattern. A polarizer configured to separate the polarization state of the second beam to reflect the third beam; and A second optical component is configured to reshape the third beam into a fourth beam by rotating its polarization state to that of the first beam. The second optical component is also configured to guide the fourth beam as one of the plurality of beams to the first optical component to generate a fifth beam that passes through the polarizer and is not reflected by the polarizer.

[0031] 21) The additive manufacturing system according to 15), wherein the energy beam is light, and the additive manufacturing system further includes: Multiple lens assemblies, including interchangeable portions, are configured to provide multiple magnifications that proportionally increase or decrease the size of the image of the incident light; and A mechanical component capable of selecting one of the lens assemblies to provide one of the magnifications, so as to convert a first image of the incident light into a second image of the incident light according to the one of the magnifications.

[0032] 22) The additive manufacturing system according to 15), wherein the energy beam is light, and the additive manufacturing system further includes: Build platform racks; and The final beam-directing device, mounted on the build platform frame, is capable of guiding the incident light emitted from one or more of the lens assemblies, such that the second beam is formed at a position holding a powder bed of powdered material, which is supported by the build platform frame.

[0033] 23) An additive manufacturing method, comprising the following steps: Provide energy beams; Positioning optically addressable patterning units to receive the energy beam and emit light as a two-dimensional patterned beam, wherein the optically addressable patterning units reject energy not required to form the two-dimensional patterned beam; The relay of the two-dimensional patterned beam and its focusing as a two-dimensional image onto the powder bed; and The rejected energy is reused by the energy processing unit.

[0034] 24) The additive manufacturing method according to 23), wherein the energy beam is light, and the additive manufacturing method further includes the following steps: One or more light beams are emitted, each of which is polarized; Each of two or more beams is split into two separate beams, each of the two separate beams corresponding to a majority polarization state or a minority polarization state, respectively; Spatially stacking the separated beams corresponding to the majority polarization states of each of the two or more beams to provide a first beam corresponding to the majority polarization states; Spatially stacking the separated beams of each of the two or more beams corresponding to the minority polarization states to provide a second beam corresponding to the minority polarization states; Apply a plurality of polarization patterns to the first beam; A few polarization patterns are applied to the second beam; Combine patterned first and second beams to provide a single beam; and The single beam is guided to the powder bed. Brief description of the attached diagram

[0035] Non-limiting and non-exhaustive embodiments of this disclosure are described with reference to the following figures, wherein, unless otherwise stated, similar reference numerals refer to similar parts throughout the various figures.

[0036] Figure 1A An additive manufacturing system is shown; Figure 1B It is a top view of the structure formed on an additive manufacturing system; Figure 2 An additive manufacturing method is shown; Figure 3A This is a base diagram showing an additive manufacturing system including a laser; Figure 3B yes Figure 3A A detailed description of the light patterning unit shown; Figure 3C This is one embodiment of an additive manufacturing system with a "switch station" used to guide and repattern light using multiple image repeaters; Figure 3D This illustrates a simple mirrored image pixel remapping; Figure 3E This illustrates a series of image transformation image relays used for pixel remapping; and Figure 3F A patternable electron beam additive manufacturing system is shown; Figure 3G It shows Figure 3F Detailed description of the electron beam patterning unit shown; Figures 4A-4C Various beam combination embodiments are shown; Figures 5A-5B An embodiment of the reflected light patterning unit is shown; Figure 6 Light recycling is shown; Figure 7 It is a polarized beam system; Figure 8 It is a flowchart of the magnification change and frame movement; Figures 9A-9B The powder bed system and the thermal management system are shown separately; Figure 10 This is a flowchart illustrating the additive forming of a temporary wall that contains powder; Figure 11A-11B An example of powder removal is shown; Figure 12A-12B The manufacturing of a long part with multiple zones is shown; Figures 13A-13C The handling of the parts at the control point is shown; Figure 14 It is a representative part with additively limited operating points; Figure 15 This is a flowchart illustrating the testing and characterization of powder samples; Figure 16 This is a diagram of a closed additive manufacturing facility; Figure 17This is a diagram of an additive manufacturing facility with multiple work areas. Detailed description

[0037] In the following description, reference is made to the accompanying drawings, which form a part of this specification, and which are illustrated by way of showing specific exemplary embodiments in which the present disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the concepts disclosed herein, and it should be understood that modifications may be made to the various disclosed embodiments, 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 limiting.

[0038] 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. Beamforming optics can receive one or more energy beams from the energy sources and form a single beam. An energy patterning unit receives or generates the single beam and transmits a two-dimensional pattern to the beam, and can reject unused energy not in the pattern. An image repeater receives the two-dimensional patterned beam and focuses it as a two-dimensional image onto a desired location on a highly fixed or movable build platform (e.g., a powder bed). In some embodiments, some or all of any rejected energy from the energy patterning unit is reused.

[0039] In some embodiments, multiple beams from a laser array are combined using a beam homogenizer. This combined beam can be directed to an energy patterning unit that includes a transmittance or reflectance pixel-addressable optical valve. In one embodiment, the pixel-addressable optical valve includes a liquid crystal module with polarizing elements and a light projection unit that provides a two-dimensional input pattern. A two-dimensional image focused by an image repeater can be sequentially guided to multiple locations on a powder bed to construct a 3D structure.

[0040] like Figure 1AAs shown, the additive manufacturing system 100 has an energy patterning system 110 with an energy source 112 that can direct one or more continuous or intermittent energy beams to a beamforming optics 114. After forming, if desired, 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 to an article processing unit 140 via an image repeater 120, typically as a two-dimensional image 122 focused near a bed 146. The bed 146 (with optional walls 148) can form a chamber to accommodate material 144 dispensed by a material dispenser 142. The patterned energy directed by the image repeater 120 can melt, fuse, sinter, merge, alter crystal structure, affect stress patterns, or otherwise chemically or physically alter the dispensed material 144 to form a structure with desired properties.

[0041] Energy source 112 generates beams or fluxes of photons (light), electrons, ions, or other suitable energy that can be guided, shaped, and patterned. Multiple energy sources can be used in combination. Energy source 112 may include a laser, incandescent lamp, concentrated solar energy, other light sources, electron beams, or ion beams. Possible laser types include, but are not limited to: gas lasers, chemical lasers, dye lasers, metal vapor lasers, solid-state lasers (e.g., fiber optics), semiconductor lasers (e.g., diodes), free-electron lasers, gas-driven lasers, "nickel-like" samarium lasers, Raman lasers, or nuclear-pumped lasers.

[0042] Gas lasers can include lasers such as helium-neon lasers, argon lasers, krypton lasers, xenon ion lasers, nitrogen lasers, carbon dioxide lasers, carbon monoxide lasers, or excimer lasers.

[0043] Chemical lasers can include lasers such as hydrogen fluoride lasers, deuterium fluoride lasers, COIL (chemical oxygen-iodine lasers), or Agil (all-gas phase iodine lasers).

[0044] Metal vapor lasers can include, for example, helium-cadmium (HeCd) metal vapor lasers, helium-mercury (HeHg) metal vapor lasers, helium-selenium (HeSe) metal vapor lasers, helium-silver (HeAg) metal vapor lasers, strontium vapor lasers, neon-copper (NeCu) metal vapor lasers, copper vapor lasers, gold vapor lasers, or manganese (Mn / MnCl2) vapor lasers.

[0045] Solid-state lasers can 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, and neodymium-doped calcium yttrium hydroxyborate Nd:YCa4O(BO3). 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 (rod, wafer / chip and fiber), 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 Solid-state lasers (glass), 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-centered lasers.

[0046] Semiconductor lasers may include 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.

[0047] 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.

[0048] The beamforming unit 114 may include a variety of imaging optics to combine, focus, diverge, reflect, refract, homogenize, adjust intensity, adjust frequency, or otherwise shape and guide 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 beams, each with a different wavelength. In other embodiments, faceted mirrors, microlenses, and refractive or diffractive optics may be used to homogenize or combine multiple beams.

[0049] Energy patterning unit 116 may include static or dynamic energy patterning elements. For example, a beam of photons, electrons, or ions may be blocked by a mask having fixed or movable elements. To increase the flexibility and ease of use 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 a combination of transmissive and reflective elements. Patterns may be dynamically modified using electronic or optical addressing. In one embodiment, a transmissive optically addressable light valve is used to rotate the polarization of light passing through the valve, wherein optically addressable pixels form a pattern defined by a light projection source. In another embodiment, a reflective optically addressable light valve includes a write beam for modifying the polarization of a readout beam. In yet another embodiment, an electronic patterning device receives an address pattern from an electrical or photon excitation source and generates patterned emission of electrons.

[0050] The rejected energy processing unit 118 is used to disperse, redirect, or utilize unpatterned energy passing through the energy patterning image repeater 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 collector" to absorb and convert any beam energy not used in defining the energy pattern into heat. In other embodiments, beamforming optics 114 may be used to recover rejected beam energy. Alternatively or additionally, rejected beam energy may be directed to the article processing unit 140 for heating or further patterning. In some embodiments, rejected beam energy may be directed to an additional energy patterning system or article processing unit.

[0051] Image repeater 120 receives a patterned image (typically two-dimensional) from energy patterning unit 116 and directs it toward article processing unit 140. In a manner similar to beamforming optics 114, image repeater 120 may include optics for combining, focusing, diverging, reflecting, refracting, adjusting intensity, adjusting frequency, or otherwise shaping and directing patterned images.

[0052] Article handling unit 140 may include a wall-mounted chamber 148 and a bed 144, as well as a material dispenser 142 for dispensing materials. The material dispenser 142 may dispense, remove, mix, provide gradients or variations in material type or particle size, or adjust the layer thickness of the material. The material may include metals, ceramics, glass, polymer powders, other fusible materials capable of undergoing a thermally induced phase transition from solid to liquid and then returning, or combinations thereof. The material may further include composites of fusible and infusible materials, wherein any one or both components may be selectively targeted by an imaging relay system to melt the fusible component while leaving along the infusible material or subjecting it to vaporization / destruction / combustion or other destructive processes. In some embodiments, slurries, sprays, coatings, wires, strips, or sheets may be used. Unwanted material may be removed for single use or recycling by using blowers, vacuum systems, sweeping, vibration, shaking, flipping, or reversing of the bed 146.

[0053] In addition to material handling components, the article handling unit 140 may include components for holding and supporting the 3D structure, mechanisms for heating or cooling the chamber, auxiliary or supporting optics, and sensors and control mechanisms for monitoring or adjusting material or environmental conditions. The article handling unit may be wholly or partially supported by a vacuum or inert gas atmosphere to reduce unwanted chemical interactions and mitigate the risk of fire or explosion, especially with reactive metals.

[0054] The control processor 150 can be connected to control any component of the additive manufacturing system 100. The control processor 150 can be connected to various sensors, actuators, heating or cooling systems, monitors, and controllers to coordinate operation. Various sensors, including imagers, light intensity monitors, and heat, pressure, or gas sensors, can be used to provide information for control or monitoring. The control processor can be a single central controller or can include one or more independent control systems. The controller processor 150 is provided with an interface for allowing the input of manufacturing instructions. The use of various sensors allows for various feedback control mechanisms that improve quality, productivity, and energy efficiency.

[0055] Figure 1B This is a base drawing showing a bed 146 supporting material 144. Structure 149 is additively manufactured using a series of sequentially applied two-dimensional patterned energy beam images (squares in the dashed outline 124). As will be understood, image patterns with non-square boundaries can be used, overlapping or interpenetrating images can be used, and images can be provided by two or more energy patterning systems. In other embodiments, directional electron beams or ion beams or printing or selective jetting systems can be combined to form the images.

[0056] Figure 2This is a flowchart illustrating one embodiment of an additive manufacturing process supported by the aforementioned optical and mechanical components. In step 202, material is placed on a bed, chamber, or other suitable support. The material may be a powder capable of being melted, fused, sintered, induced to alter its crystal structure, affect its stress modes, or otherwise chemically or physically modified to form a structure with desired properties.

[0057] In step 204, unpatterned energy is emitted by one or more energy emitters, including but not limited to solid-state or semiconductor lasers, or a power source that allows electrons to flow along wires. In step 206, the unpatterned energy is shaped and modified (e.g., intensity modulation or focusing). In step 208, this unpatterned energy is patterned, where the energy in the portion that did not form a pattern in step 210 is processed (this may include conversion into waste heat or recovery as patterned or unpatterned energy). In step 212, the patterned energy, now forming a two-dimensional image, is relayed toward the material. In step 214, the image is applied to the material, constructing a portion of a 3D structure. These steps can be repeated (loop 218) until an image (or different and subsequent images) has been applied to all necessary areas of the top layer of the material. When the energy application to the top layer of the material is complete, a new layer can be applied (loop 216) to continue constructing the 3D structure. These processes continue in cycles until the 3D structure is complete, at which point any remaining excess material can be removed or recycled.

[0058] Figure 3AThis is one embodiment of an additive manufacturing system 300 that uses multiple semiconductor lasers as part of an energy patterning system 310. A control processor 350 can be connected to various sensors, actuators, heating or cooling systems, monitors, and controllers to coordinate the operation of the multiple lasers 312, the optical patterning unit 316, and the image repeater 320, as well as any other components of the system 300. These connections are generally represented by dashed outlines 351 surrounding the components of the system 300. As will be understood, the connections can be wired or wireless, continuous or intermittent, and include the ability to provide feedback (e.g., the ability to regulate thermal heating in response to sensed temperature). The multiple lasers 312 can emit beams 301 with a wavelength of, for example, 1000 nm and a width of 90 mm × a height of 20 mm. The beam 301 is sized by an imaging optics 370 to produce a beam 303. A beam 303, 6mm wide and 6mm high, is incident on a light homogenizing device 372, which mixes the light to produce a mixed beam 305. Beam 305 then strikes an imaging assembly 374, which reshapes the light into a beam 307, which is then incident on a heated mirror 376. Mirror 376 allows 1000nm light to pass through but reflects 450nm light. A light projector 378, capable of projecting low-power light at 1080p pixel resolution and 450nm, emits a beam 309, which is then incident on the heated mirror 376. Beams 307 and 309 are overlaid in beam 311, and both are imaged onto an optically addressed light valve 380 with an image 20mm wide and 20mm high. The image formed from the homogenizer 372 and projector 378 is recreated and overlaid on the light valve 380.

[0059] An optically addressed light valve 380 is excited by light (typically in the range of 400-500 nm) and imprints a polarization rotation pattern in a transmitted beam 313 incident on a polarizer 382. The polarizer 382 separates the two polarization states, transmitting the p-polarized light into beam 317 and reflecting the s-polarized light into beam 315, which is then sent to a beam collector 318 that processes rejected energy. As will be understood, in other embodiments, the polarization can be reversed, with the s-polarization formed in beam 317 and the p-polarization reflected into beam 315. Beam 317 enters a final imaging assembly 320 including optics 384, which resizes the patterned light. This beam is reflected by a movable mirror 386 to beam 319, which terminates in a focused image applied to a material bed 344 in an article handling unit 340. The depth of field in the image is selected to provide optimal focus across multiple layers within a range of layer errors or offsets.

[0060] The bed 390 can be raised or lowered (indexed) within the chamber wall 388 containing material 344 dispensed by the material dispenser 342. In some embodiments, the bed 390 can be held stationary, and the optics of the final imaging assembly 320 can be raised or lowered vertically. Material dispensing is provided by a sweeping mechanism 392, which can uniformly distribute the powder held in the hopper 394 and provide new material layers as needed. A 6 mm wide × 6 mm high image can be sequentially guided at different positions on the bed by a movable mirror 386.

[0061] When powdered ceramic or metallic materials are used in this additive manufacturing system 300, the powder can be dispersed into a thin layer of approximately 1-3 particles thick on top of a base substrate (and subsequent layers) as the part is built. When the powder is melted, sintered, or fused by a patterned beam 319, it bonds with the underlying layer to create a solid structure. The patterned beam 319 can be operated in a pulsed manner at 40 Hz, moving to a subsequent 6 mm × 6 mm image position at intervals of 10 ms to 0.5 ms (ideally 3 to 0.1 ms) until a selected patterned area of ​​the powder has melted. The bed 390 then lowers itself to a thickness corresponding to one layer, and a sweeping mechanism 392 disperses a new layer of powder material. This process is repeated until the 2D layer establishes the desired 3D structure. In a particular embodiment, the article 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).

[0062] Figure 3B The diagram shows Figure 3A More detailed operation of the light patterning unit 316. For example, in Figure 3BAs seen, the representative input pattern 333 (here seen as the number "9") is defined in the light projected by the beam 309 toward the reflector 376 in an 8x12 pixel array. Each gray pixel represents a light-filled pixel, 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. The unpatterned light 331 forming the beam 307 is guided and passes through the hot / cold reflector 376, where the beam 307 combines with the patterned beam 309. After reflection by the hot / cold reflector 376, the patterned beam 311 formed by the overlap of the beams 307 and 309 in the beam 311, and both, are imaged onto the 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 and 311 to selectively prevent the polarization state of the polarized light 307 and 311 in the pattern of the number "9" from being rotated to 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 rotated state is rejected by polarizer mirror 382 and enters beam 315 carrying negative pixel pattern 337 consisting of the lightless digit "9".

[0063] Other types of optical valves can be used in place of or in combination with the described optical valves. Reflective optical valves or optical valves based on selective diffraction or refraction can also be used. In some embodiments, non-optically addressed optical valves can be used. These can include, but are not limited to, electrically addressable pixel elements, movable mirror or micromirror systems, piezoelectric or micro-driven 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 location, thereby injecting a pattern onto the electron beam exiting the valve.

[0064] Figure 3C This is one embodiment of an additive manufacturing system that includes a switch station system that enables the reuse of patterned two-dimensional energy. Similar to... Figure 1AIn the discussed embodiment, 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 beamforming optics 114. After forming, the beams are patterned in two dimensions by an energy patterning unit 230, typically directing some energy to a rejected energy processing unit 222. The patterned energy is relayed to one or more article processing units 234A, 234B, 234C, or 234D via one of a plurality of image repeaters 232, typically as a two-dimensional image focused near a movable or fixed-height bed. The bed (with optional walls) can form a chamber to contain material dispensed by a material dispenser. The patterned energy directed by the image repeater 232 can melt, fuse, sinter, merge, alter crystal structure, affect stress patterns, or otherwise chemically or physically alter the dispensed material to form a structure with desired properties.

[0065] In this embodiment, the rejected energy processing unit has multiple components to allow the reuse of rejected patterned energy. Repeaters 228A, 228B, and 22C can respectively direct energy to generator 224, heating / cooling thermal management system 225, or energy harvester 226. Optionally, repeater 228C can direct patterned energy to image repeater 232 for further processing. In other embodiments, patterned energy can be directed by repeater 228C to repeaters 228B and 228A to insert an energy beam provided by energy source 112. Patterned images can also be reused using image repeater 232. Images can be redirected, inverted, mirrored, sub-patterned, or otherwise transformed to be distributed to one or more article 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 energy intensity for the bed or reduce manufacturing time.

[0066] Figure 3D This is a base map 235 illustrating a simple geometric transformation of a rejected energy beam for reuse. The input pattern 236 is directed to an image repeater 237 capable of providing 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 directly directed to the article processing unit to increase production or beam intensity, rather than being wasted in the beam collector.

[0067] Figure 3E This is a background diagram 235 illustrating multiple conversions of the rejected energy beam for reuse. The input pattern 236 is directed to a series of image repeaters 237B-237E capable of providing pixel patterns 238.

[0068] Figure 3F and 3G The illustration shows a non-light-based energy beam system 240, which 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 via 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 including imaging coils 246A and 246B. Final positioning of the patterned image is provided by a deflection coil 248 capable of moving the patterned image to a desired position on a bed of the additive manufacturing part 249.

[0069] In another embodiment supporting light recovery and reuse, multiple beams from one or more multiplexed light sources are provided. The multiple beams can be reshaped and mixed to provide a first beam. A spatial polarization pattern can be applied to the first beam to provide a second beam. The polarization state of the second beam can be separated to reflect a third beam, which can then be reshaped into a fourth beam. The fourth beam can be introduced as one of the multiple beams to generate a fifth beam. In practice, 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 spatial polarization valves or optical valves operating in polarization modification mode, the overall transmitted light power may be unaffected by the pattern applied by the optical valve. This advantageously results in the light passing through the optical valve being effectively redistributed into the desired pattern, increasing the light intensity proportional to the amount of patterned area.

[0070] Combining beams from multiple lasers into a single beam is one way to increase beam intensity. In one embodiment, wavelength-selective mirrors or diffractive elements can be used to combine multiple beams, each with a different wavelength. In some embodiments, reflective optics that are insensitive to wavelength-dependent refraction effects can be used to guide multi-wavelength beams.

[0071] Patterned light can be guided using movable mirrors, prisms, diffractive optics, or solid-state optical systems that do not require substantial physical movement. In one embodiment, the magnification and image distance associated with the intensity and pixel size of incident light at a location on the top surface of the powder bed can be determined for an additive 3D printing job. One of a plurality of lens assemblies can be configured to provide incident light with magnification, wherein the lens assembly includes both a first set of optical lenses and a second set of optical lenses, and the second set of optical lenses is interchangeable from the lens assembly. Rotation of one or more sets of mirrors mounted on a compensation frame and a final mirror mounted on a build platform frame can be used to guide incident light from the precursor mirror to a location on the top surface of the powder bed. Translational movement of the compensation frame and the build platform frame also ensures that the distance of the incident light from the precursor mirror to the location on the top surface of the powder bed is substantially equal to the image distance. In practice, this enables rapid changes in beam delivery size and intensity at locations across build regions of different powder materials, while ensuring high system availability.

[0072] In some embodiments, multiple build chambers, each with a build platform to hold the powder bed, can be used in conjunction with multiple optomechanical components arranged to receive and guide one or more incident energy beams into the build chamber. Multiple chambers allow for the simultaneous printing of one or more print jobs within one or more build chambers. In other embodiments, removable chamber sidewalls can simplify the removal of the print object from the build chamber, thereby allowing for rapid exchange of powder material. The chamber may also be equipped with adjustable process temperature control.

[0073] In another embodiment, one or more build chambers may have build chambers maintained at a fixed height, while the optics are vertically moved. The distance between the final optics of the lens assembly and the top surface of the powder bed can be set substantially constant by shifting the final optics upward by a distance equivalent to the thickness of the powder layer, while keeping the build platform at a fixed height. Advantageously, large and heavy objects can be fabricated more easily than by vertically moving the build platform, as precise micron-level movement of the build platform is not required. 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 kg) will benefit most from keeping the build platform at a fixed height.

[0074] In one embodiment, a portion of the powder bed layer may be selectively melted or fused to form one or more temporary walls from the molten portion of the powder bed layer, to accommodate another portion of the powder bed layer on the construction platform. In selected embodiments, fluid channels may be formed in one or more of the first walls to achieve improved thermal management.

[0075] Improved powder handling can be another aspect of improving additive manufacturing systems. The build platform supporting the powder bed can be tilted, inverted, and rocked to essentially 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 assist in powder removal and disposal.

[0076] Some embodiments of the disclosed additive manufacturing system can be configured to easily handle parts longer than the available chambers. A continuous (long) part can proceed longitudinally from a first zone to a second zone. In the first zone, selected particles of particulate material can be merged. In the second zone, unmerged particles of particulate material can be removed. A first portion of the continuous part can proceed from the second zone to a third zone, while the final portion of the continuous part is formed within the first zone, and the first portion remains in the same position occupied by the first portion in both the lateral and transverse directions within the first and second zones. In practice, additive manufacturing and cleaning (e.g., separating and / or recycling unused or unmerged particulate material) can be performed in parallel (i.e., simultaneously) at different locations or zones on the part conveyor without stopping to remove particulate material and / or parts.

[0077] In another embodiment, additive manufacturing capabilities can be enhanced by using a housing that restricts gaseous material exchange between the interior and exterior of the housing. An airlock provides an interface between the interior and exterior; the interior has multiple additive manufacturing chambers, including those supporting a molten power bed. A gas management system maintains gaseous oxygen within the housing at or below a limiting oxygen concentration, thereby increasing flexibility in the types of powders and processing methods available to the system.

[0078] In another manufacturing embodiment, performance is improved by including the 3D printer within the housing, enabling the printer to create parts weighing 2,000 kg or more. A gas management system maintains gaseous oxygen within the housing at a concentration below atmospheric levels. In some embodiments, wheeled vehicles can transport components from inside the housing to locations outside both the housing and the airlock via an airlock (due to the airlock's operation to buffer between the gaseous environments inside and outside the housing).

[0079] Other manufacturing embodiments involve the real-time collection of powder samples in a powder bed fusion additive manufacturing system. An ingester system is used for the in-process collection and characterization of powder samples. This 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 the following: auditing, process adjustments, or actions, such as modifying printer parameters or verifying the correct use of authorized powder materials.

[0080] Another improvement to the additive manufacturing process is described, which can be provided by manipulating devices such as cranes, lifting frames, robotic arms, or similar equipment that allow for the manipulation of parts that are difficult or impossible for humans to move. Manipulating devices can grasp various permanent or temporary additive manufacturing manipulator points on the part, enabling the part to be repositioned or maneuvered.

[0081] Figure 4A A beam combining system 400 with multiple wavelength semiconductor lasers and using transmission imaging optics is illustrated. As will be understood, the laser power and wavelength discussed are exemplary, as are the selected wavelengths reflected or transmitted by the wavelength filters. More or fewer lasers can be used with appropriate variations in wavelength filter positioning and use. In some embodiments, solid-state lasers may be replaced by or combined with semiconductor lasers. In other embodiments, see reference, for example... Figure 1A Other laser types discussed, including gas, chemical, or metal vapor lasers, can be used. In one embodiment, the recovery and reuse of rejected light can replace the laser. Rejected light available in the additive manufacturing system can be collected, homogenized, and reintroduced into the beamline. Advantageously, recovering and reusing rejected light can increase beam intensity and reduce the energy costs associated with the system.

[0082] exist Figure 4AIn this process, a semiconductor laser 406 with a first wavelength (1020 nm) emits a photon beam 407 of 33.3 kW corresponding to the wavelength, and a semiconductor laser 408 with a second wavelength (1000 nm) emits a photon beam 409 of 33.3 kW corresponding to the wavelength. These are then combined using a wavelength filter 410 that transmits 1020 nm photons but reflects 1000 nm photons. This results in a combined dual-wavelength beam 411 of 66.6 kW. A semiconductor laser 412 with a third wavelength (980 nm) emits a photon beam 413 of 33.3 kW corresponding to the wavelength, and this is then combined with beam 411 using a wavelength filter 414. The wavelength filter 414 transmits the 1020 and 1000 nm beams but reflects the 980 nm beam, producing a three-wavelength beam 415 of 99.9 kW. A fourth-wavelength (960nm) semiconductor laser 417 emits a 33.3kW photon beam 418 of the corresponding wavelength, which is then combined with the beam 415 using a wavelength filter 416 that transmits 1020nm, 1000nm, and 980nm photons but reflects 960nm, resulting in a 133.2kW four-wavelength beam 419. This beam enters the optical imaging system with, for example, a beam size of 20mm × 20mm 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 effect of wavelength variation on the imaging beam's capability. The beam exits the optical system at 421, which is a series of lenses utilizing three materials: ZeruDur, ULE 7972, and C79-79, to eliminate the effect of wavelength variation on the imaging beam's capability. Due to the increased beam intensity at 422° via the optical system, the beam is now 6 mm wide × 6 mm high with a divergence of 3.67 degrees, resulting in an intensity of 370 kW / cm². 2 It is sufficient for additive manufacturing of stainless steel metals, such as powder.

[0083] To achieve optimal performance, proper selection of lens materials is essential. Transmissive optics, such as Lens 420, can be made of fused silica glass. Its extremely low absorption coefficient near 1000 nm reduces thermal expansion issues, and the extremely low coefficient of thermal expansion of fused silica further reduces the lens's thermal expansion. The use of fused silica allows optics to withstand higher strength without heating or expansion, which can lead to breakage, changes in the glass's refractive index, changes in the glass's shape, and consequently, changes in the focal length. Undesirable optical changes can also be reduced by using two or more materials. Each material can have a different refractive index that varies with wavelength. When used in appropriate combinations, changes in refractive index and optical path length are offset, and the focal length remains unchanged with wavelength.

[0084] Figure 4BThe illustration shows an alternative beam combination system 401 that includes a combination of multiple wavelength semiconductor lasers and uses reflective imaging optics to reduce the aforementioned problems associated with transmissive optics. Like Figure 4A Similar to the beam combining system 400, it is understood that the laser power and wavelength in the system 401 discussed are exemplary, as are the selected wavelengths reflected or transmitted by the wavelength filter. With appropriate variations in wavelength filter positioning and use, more or fewer lasers can be used. Various types of lasers can be used, and in one embodiment, rejected light can be recovered and reused instead of a laser. Rejected light available in an additive manufacturing system can be collected, homogenized, and reintroduced into the beamline. Advantageously, reflective optics improve problems related to semiconductor laser chirp (wavelength shift over time) during startup transients and throughout its lifetime. The use of reflective optics prevents detuning of diode laser focusing due to this effect and does not affect the achieved resolution or imaging capability. Furthermore, by using reflective optics, wavelength differences caused by variations in laser operating temperature do not affect resolution or imaging capability.

[0085] exist Figure 4B In this configuration, a semiconductor laser 423 with a first wavelength (1020 nm) emits a 33.3 kW photon beam 424 of the corresponding wavelength, and a semiconductor laser 425 with a second wavelength (1000 nm) emits a 33.3 kW photon beam 426 of the corresponding wavelength. These beams are combined using a wavelength filter 427 that transmits 1020 nm photons but reflects 1000 nm photons to produce a dual-wavelength beam 428 of 66.6 kW. A semiconductor laser 429 with a third wavelength (980 nm) emits a 33.3 kW photon beam 430 of the corresponding wavelength. These beams are combined with beam 428 using a wavelength filter 431 that transmits 1020 and 1000 nm photons but reflects 980 nm to produce a tri-wavelength beam 432 of 99.9 kW. A semiconductor laser 433 with a fourth wavelength (960 nm) emits a 33.3 kW photon beam 434 of the corresponding wavelength. These beams are combined with beam 432 using a wavelength filter 435 that transmits 1020nm, 1000nm, and 980nm photons but reflects 960nm photons, producing a four-wavelength beam 436 of 133.2kW. This beam enters the optical imaging system with, for example, a beam size of 20mm × 20mm and a divergence of 1.1 degrees at the reflecting optics 437. The reflecting optics are wavelength-independent and do not affect the ability to image the beam. The beam exits the beam-combining optical system 401 at the reflecting optics 438. Due to the passage through the optical system, the intensity of beam 439 has increased, now measuring 6mm wide × 6mm high, with a divergence of 3.67 degrees, resulting in an intensity of 370kW / cm². 2 It is sufficient for additive manufacturing of metals such as powdered stainless steel.

[0086] Figure 4C This describes an alternative embodiment of a beam combining system 440 that uses diffractive imaging optics 444 to combine beams 443 from lasers 442 of the same or multiple wavelengths. The diffractive optics can be shaped or patterned to receive the beams 443 and reflect them along substantially the same beam axis. As will be understood, although in Figure 4C The diagram illustrates a diffractive optical element that reflects a beam. In other embodiments, the diffractive optical element may transmit a beam, or a combination of reflective, transmissive, or other suitable beam-directing optical components or parts may be used.

[0087] Figure 5A The reflective optical addressing light valve system 500A is useful in additive manufacturing systems such as those disclosed herein. Reflective light valves eliminate the need for light transmission through a transparent semiconductor for optical patterning, where even small amounts of absorption at high average power levels can lead to undesirable and catastrophic heating. Reflective light valves also allow for easier cooling on the reflective surface, simultaneously cooling on opposite sides of the write and read beams.

[0088] As in Figure 5AAs seen, the 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, optically transparent to both 1000 nm and 700 nm light, is made of a glass substrate (C79-79 fused silica) 501, which has anti-reflective coatings on both sides at 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 dimensions of spacer spheres 508 defining a 2.5-micrometer gap, which is adjusted for maximum contrast ratio when transmitting 1000 nm light in a two-way path. Layer 503 is made of 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 ITO layer with attached solder joints 512 and connected to layer 505 via another solder joint 513 through an AC voltage source 514. A patterned write beam is emitted from a projector source at 700 nm and incident on layer 503 after passing through layers 504, 501, 505, 506, 507, 502, 509, and 510. Upon impact with the write beam on layer 503, electrons move from the valence band to the conduction band, significantly increasing the local conductivity of layer 503 and allowing current to flow from layer 511 through layers 503, 510, 509, 502, 507, and 506 to layer 505. As the current flows through the TN liquid crystal 502, it causes rotation within the liquid crystal, resulting in polarization rotation in the transmitted light. The "read" beam 516 is p-polarized and, after transmission through 504, 501, 505, 506, 507, 502, and 509, is incident on 510. At 509, it is reflected and transmitted back through 509, 502, 507, 506, 505, 501, and 504 to exit the optical valve system 500A. This beam is then incident on polarizer 517, which reflects the beam, resulting in s-polarization of the reflected beam 518, and transmits it, resulting in p-polarization of the transmitted beam 519. Although the absorption in the device is very low, the HR coating 509 does not completely reflect the beam, and some energy is absorbed. This energy is removed by radiation, conductive cooling, or convection cooling 520.

[0089] Figure 5BAn alternative reflective optical addressing light valve 500B with cooling on one side, where the write and read beams are incident from different sides, is shown. The valve consists of a high-transmittance layer 521, a twisted nematic (TN) liquid crystal layer 522, and a photoconductor layer 523. The high-transmittance layer, optically transparent to 1000 nm and 700 nm light, is made of a glass substrate (C79-79 fused silica) 521 with anti-reflective coatings on both sides at 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 259. The exact spacing of 522 is given by the dimensions of spacer spheres 528 defining a 2.5 μm gap, which is adjusted for maximum contrast when transmitting 1000 nm light in a two-way path. Layer 523 is made of single-crystal silicon semiconductor, with a highly reflective dielectric coating applied at 530 that reflects at 1000 nm. Layer 531 is another layer of ITO, having attached solder joints 532 and connected to layer 525 via an AC voltage source 534 through another solder joint 533. A patterned write beam is emitted from a projector source at 700 nm and, after passing through an optional convection / conductivity substrate 540 and through the ITO coating 531, is incident on 523. When the write beam strikes 503, electrons move from the valence band to the conduction band, significantly increasing the local conductivity of 523, allowing current to flow from 531 through 523, 530, 529, 522, 527, and 526 to 525. When the current flows through the TN liquid crystal 522, it causes rotation within the liquid crystal 522, resulting in polarization rotation in the transmitted light. The "read" beam 536 is p-polarized and, after transmission through 524, 521, 525, 526, 527, 522, and 529, is incident on 530. At point 529, it is reflected and transmitted through 509, 522, 527, 526, 525, 521, and 524 back to exit the light valve. This beam is then incident on polarizer 537, which reflects the beam, resulting in s-polarization of the reflected beam 538, and transmits it, resulting in p-polarization of the transmitted beam 539. Although the absorption in the device is very low, the HR coating 529 does not completely reflect the beam, and some energy is absorbed. This energy is removed by radiation, conduction, or convection cooling 540.

[0090] To help better understand and comprehend various system embodiments, including alternative or additional optical systems, chamber designs, powder handling systems and methods, structure formation, part creation and manipulation, the use of various additive manufacturing systems, and high-volume manufacturing methods suitable for automated or semi-automated plants, the following disclosure will help to understand and comprehend the various novel aspects of the disclosed systems, methods, and structures.

[0091] Figure 6The layout of an exemplary apparatus 600 for laser recovery 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 p-polarized light at 700 nm, with a size of 7.9 cm × 7.9 cm and a divergence of 7.6 mrad. The beams emitted by light sources 601, 602, and 603 may be multiplexed together by a first optical assembly 604, which may include a series of mirrors to allow the beams to be brought as close together as possible. These beams are then reshaped and mixed using optical device 605 to produce a 33.3 kW, 4.7 cm × 4.7 cm beam with a divergence of 70.4 mrad. The beam 606 can then be incident on a spatial polarization valve 607, which applies a spatial polarization pattern to the beam 606 by rotating the polarization of the selected pixel from p-polarization to s-polarization to provide the beam 8. With appropriate modifications, the selected pixel can be formed to provide the beam by rotating it from s-polarization to p-polarization. In other embodiments, grayscale pixels can be created by partial rotation. After interacting with polarizer 609, the s-polarization state of the beam 608 can be reflected into the beam 610. The precise fraction can be given as a function of the fraction of light patterned by the spatial polarization valve 607. The beam 10 can enter a second optical assembly 611, which may include a series of mirrors, reshaping lenses, waveplates, or other optical components, and the beam 10 can be modified into a 7.9 cm × 7.9 cm beam and then reintroduced into the system as if it were a light source 612, along with one or more original light sources 601, 602, and 603.

[0092] The process for light recovery may include the step of multiplexing multiple beams comprising at least one or more beams from one or more light sources 601, 602, and 603. The multiple beams may be reshaped and mixed to provide a first beam. A spatial polarization valve 607 of device 600 applies a spatial polarization pattern to the first beam to provide a second beam. A polarizer 609 of device 600 separates the polarization state of the second beam 608 to reflect a third beam (e.g., beam 610). A second optical component 611 of device 600 reshapes the third beam into a fourth beam, and the fourth beam is introduced as one of multiple beams into a first optical component 604 to produce a fifth beam (e.g., beam 613), which is emitted by polarizer 609 and is not reflected by polarizer 609.

[0093] Figure 7An example optical assembly 700 is shown, illustrating a polarization combination according to this disclosure to achieve twice the original semiconductor laser intensity (limit). Semiconductor lasers are typically polarized to about 70-90% in a polarization state. When patterning light using polarization rotation methods, 10-20% of the light in undesirable polarization states may be unused (rejected). To avoid this loss, polarization combination and patterning can be used to improve transmission efficiency or double the combined intensity, or both.

[0094] In one embodiment, two or more beams of a first intensity are provided, each of the two or more 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 beams, and the two or more beams are combined to provide a single beam of a second intensity greater than the first intensity. In a second embodiment, more than one laser with arbitrary polarization states can be used. Polarizers are used to separate the beams into their respective polarization states, and the beams of corresponding polarization states are spatially stacked together by spatial positioning to produce two effective beams, one beam for each polarization state. These two beams with different polarization states are then passed through an optical modulator associated with their perspective polarization states, and then combined by applying a polarization state pattern to the beams, and subsequently by polarization combination. This method uses all the light in the process, which allows for higher laser utilization, achieving minimal to zero loss due to polarization state variations, and achieving better system efficiency.

[0095] Optical component 700 may include Figure 7Some or all of the components shown are described below. Light sources 701 and 702 each function as a high-power photon source. In some embodiments, light sources 701 and 702 may each be a semiconductor laser array with a power of 33.3 kW, emitting photons at 1000 nm, shaped and mixed into a 20 mm wide × 20 mm square beam. The emitted light may be 90% polarized in the majority state p, resulting in beams 703 and 704. The emitted beams 703 and 704 may be incident on polarizers 705 and 706, respectively. Polarizers 705 and 706 may reflect minority state s-polarization to generate beams 709 and 7010, which may be incident on beam collector 7011. Polarizers 705 and 706 may transmit p-polarization to generate beams 706 and 707, which may be incident on polarization-rotating optical addressing valves 712 and 13, respectively. Each of light valves 712 and 713 can apply the same image to beams 706 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 generate beams 718 and 719, respectively, which can contain 20% energy and can be collected by beam collector 720. Polarizers 716 and 717 can transmit p-polarization to generate 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 p-polarization to s-polarization to generate beam 724. Beams 721 and 724 can be incident on mirrors 725 and 726, respectively, to produce beams 727 and 728. Beam 727 can be incident on mirror 729 to produce beam 730, which can be incident on polarizer 731 with p-polarization. Beam 728 with s-polarization can be incident on polarizer 731, which can reflect the s-polarization of beam 728 and transmit the p-polarization of beam 730 to produce beam 732. Beam 732 can be a beam with twice the intensity of a single polarization state from light sources 701 or 702, with a total initial intensity 1.8 times the original due to 90% initial polarization, and proportionally less than this total initial intensity because 20% of the polarization mapping image is applied at light valves 712 and 713. The total propagation intensity at beam 732 can be 1.44 times the initial intensity for a total transmitted power of 47.52 kW. Imaging onto the original 20x20mm square, if the divergence angle remains constant, the final intensity could be 11.88 kW / cm². 2 .

[0096] In bed-of-future additive manufacturing (BFM), as powder material is processed (with or without chemical bonding), a source image of a beam of light with sufficient energy is directed to a position on the top surface of the powder bed (the printing surface) to form a monolithic object. The resolution (or pixel size) of the optical system used in BFM depends on whether the printing surface coincides with the focal plane of the final optics in the optical system, or, in the case of the imaging system, whether the distance between the lens and the imaging plane of the optics performing the imaging operation remains substantially constant for a given lens configuration. To be able to print large objects in BFM, precise control of the image position on the printing 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 due to their varying bond energy thresholds. If changes in intensity are needed when altering the powder type or powder size distribution, it may be necessary to shut down the optical system to reinstall and realign the imaging lens.

[0097] To address issues related to variations in intensity and resolution, the process is described below. Figure 8 This is a flowchart 800 illustrating the steps of using a dynamic optics assembly that may include an image relay rack. In step 810, information is obtained or otherwise determined to find the minimum resolution (pixel size of incident light) of the object to be printed in the powder bed fused additive manufacturing system. Based on intensity and resolution requirements, the magnification of the incident light containing image information and the image distance of the dynamic optics assembly are calculated. The magnification can convert a first size of the image at the precursor image plane into a second size of the image at the printing surface (the top surface of the powder bed). The incident light may originate from an energy source and be transmitted through the precursor image plane where image information can be created. Process 800 may involve storing geometric data of the object, and position and rotation control data of the dynamic optics assembly.

[0098] At step 820, process 800 may include configuring a mechanical component and one or more lens assemblies to achieve a magnification suitable for the powder material obtained at 810. The configuration of one of the mechanical component and lens assemblies may involve rotation of the mechanical component, exchange of a second set of optical lenses, or removal of a second set of optical lenses.

[0099] In step 830, multiple rotations can be performed to guide incident light from the precursor image plane to a desired location on the printing surface (e.g., the top surface of the powder bed) in each successive step of the powder bed fused additive manufacturing process. At step 840, the dynamic optics component can perform multiple translational movements to maintain a constant image distance from the precursor image plane to each location on the printing surface (e.g., the top surface of the powder bed) in each successive step of the powder bed fused additive manufacturing process. Vertical movement of the powder bed or the optics component can be used to maintain a fixed separation of the powder bed relative to the final lens.

[0100] The apparatus for 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 the precursor image plane is incident on a lens assembly within a lens barrel. The lens assembly can be configured by rotating the lens barrel to achieve the exchange, removal, use of dynamic lenses that change shape, electronic lens exchange, beam redirection systems, photoelectrically controlled refractive beam directing devices, or combinations thereof, to have an appropriate magnification of 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 mirror and guided to a mirror mounted on a compensation frame, where it is reflected and then incident on a final mirror mounted on the build platform frame. The final mirror guides the beam containing image information through a final lens toward the top surface of the powder bed, reproducing and magnifying the object image in an image plane that may be formed thereon. The powder material on the powder bed may be melted to form the shape of the object image. The build platform frame then moves to the next position until the designated location on the top surface of the powder bed is bonded to the layer. A new layer of powder material is then dispensed, and the build platform can move downwards a distance equal to the thickness of the powder material layer to maintain a constant distance from the build platform frame. The cycle begins for the new layer to continue the additive printing process.

[0101] Figure 9AAn example scenario 900 of an intermediate point in a powder bed fused additive manufacturing printing process according to the present disclosure is shown. Example scenario 800 shows the upward movement of a component in a build chamber while controlling the depth of field using a fixed build platform 930. The build platform 930 may have an area of ​​0.5 m × 1 m, on which powder can be distributed during the printing cycle. In one embodiment, the build platform 930 moves to a position below the gantry 905 and locks in place. Vertical columns 903(1) - 903(4), each at a height of 3 m, support a gantry 907 mounted on the gantry 905. A powder distribution unit 910, a compaction function 911, and a reflector 917 may be mounted on the gantry 907 for translational movement in the horizontal plane. The gantry 905 is shown above... Figure 8 The position above the powder bed 920 indicates that printing may be in progress. The powder bed 920 contains powder layers and the printed object at the completion of each stage. A new powder layer 925 is dispensed from the powder dispensing unit 910, which includes powder diffusion and compaction. A beam 921 incident from the print head (not shown) can be reflected by a mirror 917 to become a beam 922 that impacts position 923 in the new powder layer 925. Printing can occur by melting, sintering, fusion, or otherwise agglomerating the powder at position 923 in the new powder layer 925. The distance between the mirror 917 and position 923 in the new powder layer 925 is a depth of field that needs to be strictly controlled to meet resolution requirements. Arrow 970 indicates upward movement of the frame stage 905, which supports the frame 907, powder dispensing unit 910, mirror 917, and, in some embodiments, surrounding chambers or walls. During this process, the build platform 930 remains locked in place, and the frame 907 (and / or the chamber and chamber walls) moves relative to the build platform 930. This arrangement is particularly useful for embodiments discussed below, where the build platform 930 is large and will need to support a large amount of heavy material that is not easily moved vertically with the required precision.

[0102] In some embodiments, the construction platform 930 of example scenario 900 may have an area greater than 0.25 square meters. Alternatively, the construction platform 930 of example scenario 900 may have an area greater than 0.5 square meters. Alternatively, the construction platform 930 of example scenario 900 may have an area greater than 1 square meter. Alternatively, the construction platform 930 of example scenario 900 may have an area greater than 5 square meters. Alternatively, the construction platform 930 of example scenario 900 may have an area greater than 10 square meters. Alternatively, the construction platform 930 of example scenario 900 may have an area greater than 50 square meters.

[0103] In some embodiments, the powder bed 920 of the printing object including example scenario 900 may have a mass greater than 10 kg. Alternatively, the powder bed 920 of the printing object including example scenario 900 may have a mass greater than 50 kg. Alternatively, the powder bed 920 of the printing object including example scenario 900 may have a mass greater than 100 kg. Alternatively, the powder bed 920 of the printing object including example scenario 900 may have a mass greater than 500 kg. Alternatively, the powder bed 920 of the printing object including example scenario 900 may have a mass greater than 1,000 kg. Alternatively, the powder bed 920 of the printing object including example scenario 900 may have a mass greater than 2,000 kg. Alternatively, the powder bed 920 of the printing object including example scenario 900 may have a mass greater than 5,000 kg. Alternatively, the powder bed 920 of the printing object including example scenario 900 may have a mass greater than 10,000 kg.

[0104] In some embodiments, the build platform 930 of example scenario 900 may have an area greater than 0.25 square meters, and the powder bed 920 including the printed object of example scenario 900 may have a mass greater than 10 kilograms.

[0105] Powder bed melting technology processes powder materials to form monolithic objects from metal, ceramic, and plastic powders. Sufficient energy is required to bring the powder to its appropriate melting / sintering / alloying temperature or phase transformation temperature. If the powder material begins to approach its phase transformation temperature, less energy may be needed to complete the phase transformation. Powder bed melting additive manufacturing can benefit from preheating the powder bed to reduce the amount of energy delivered by lasers or other energy sources. This allows for the use of lower-intensity lasers and shorter dwell times to bond the powder, thereby increasing productivity.

[0106] Some powder materials, such as metals, may require post-processing heat treatment to reduce stress concentration and increase mechanical strength. Post-processing heat treatment can 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 / build platform and by using feedback algorithms to control the heating / cooling rate. Heat loss can be reduced by using insulating materials inside the walls of the build chamber.

[0107] Reference Figure 9B The discussion applies to thermal management systems used in conjunction with the powder bed and chamber. Figure 9BAn example apparatus of a laser-based powder bed fused 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 directing system / driver 955, which are part of a printhead 910B. Optomechanical components 930(1)-930(N) can distribute the energy beam for the printhead 910B through system 900B. Processor 901 and memory 940 enable data input, monitoring, control, and feedback control using various sensors. These systems may include input of 3D object data 941, printhead controls 942, build platform controls 943, optomechanical component controls 944, and build chamber controls 945.

[0108] The laser-based powder bed fusion additive manufacturing system 900 may include one or more build chambers. For illustrative purposes and without limitation, Figure 9B The diagram illustrates one or more build chambers of system 900 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 from the powder material. Each of the build chambers 920B(1)-920B(N) may have different dimensions and may be interchangeable with each other within the powder bed melt additive manufacturing system 900. Build chambers 920B(1)-920B(N) may have removable doors to facilitate the removal of powder from one side of the build chambers 920B(1)-920B(N) after build. During powder bed melt 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.

[0109] In some embodiments, heating / cooling elements 926(1)-926(N) and temperature sensors 928(1)-928(N) may be embedded in the walls / ceiling of the building chambers 920B(1)-920B(N) to control the thermal environment within the building chambers 920B(1)-920B(N).

[0110] In some embodiments, the heating / cooling elements 926(1)-926(N) may be fluid channels capable of heat exchange. The fluid may be heated or cooled outside the building chambers 920B(1)-920B(N) and exchange heat with the walls / 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.

[0111] In some embodiments, the heating / cooling elements 926(1)-926(N) can be resistance heating elements and thermionic cooling elements, respectively.

[0112] In some embodiments, temperature sensors 928(1)-928(N) may be thermocouples embedded in the wall / ceiling of the building chamber 920(1)-920(N).

[0113] In some embodiments, temperature sensors 928(1)-928(N) may be infrared cameras mounted on the walls / ceilings within the building chambers 920(1)-920(N).

[0114] In some embodiments, each of the chambers 920(1)-920(N) may include radiation shielding on the walls / ceiling of the chambers 920(1)-920(N) to reduce heat loss.

[0115] In some embodiments, constructing chambers 920(1)-920(N) may include a low thermal conductivity material as part of the walls / ceiling.

[0116] In some embodiments, each of the build platforms 924(1)-924(N) may be able to move vertically or be fixed at a given height during powder bed melt additive manufacturing. The build platforms 924(1)-924(N) may have different dimensions and support powder beds of different qualities. The build platforms 924(1)-924(N) may be removed from the build chambers 920(1)-920(N) on tracks, wheels or other means.

[0117] Figure 10 A method for minimizing powder volume requirements during build operations is described. According to this disclosure, process 1000 can be used to print a variable printing chamber wall for powder bed melting in a powder bed melting additive manufacturing system. At 1010, process 1000 may involve dispensing powder material to form a first layer of powder bed on a support surface of the build platform.

[0118] 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 molten portion of the first layer of the powder bed. One or more first walls may accommodate another portion of the first layer of the powder bed on the build platform. In some embodiments, one or more first walls may include multiple walls surrounding a region inside the build platform to create a region 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 molten portion of the second layer of the powder bed. One or more second walls may accommodate another portion of the second layer of the powder bed.

[0119] In some embodiments, one or more first walls may include a plurality of first walls surrounding another portion of a first layer of the powder bed above a first region of the building platform. Furthermore, the one or more second walls may include a plurality of second walls surrounding another portion of a 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.

[0120] In some embodiments, one or more first walls may include at least one wall along at least one of at least one of the plurality of perimeters of the construction platform. Additionally, the remaining one or more perimeters of the plurality of perimeters of the construction platform may border one or more structural walls. In some embodiments, process 1000 may also involve causing relative movement between the construction platform and one or more structural walls in a direction perpendicular to the support surface of the construction platform. Furthermore, process 1000 may involve dispensing powder material onto a first layer of the powder bed and one or more first walls to form a second layer of the powder bed. Furthermore, process 1000 may involve selectively melting a portion of the second layer of the powder bed to increase the height of one or more first walls.

[0121] In another embodiment, a temporary wall may be fabricated to have conduits, cavities, or porous portions capable of supporting fluid flow (hereinafter referred to as "fluid passages"). Fluid passages may be open or partially closed and may be configured to connect to external conduits, hoses, sprayers, or other fluid communication systems. Air, nitrogen, water, high temperatures, or silicone oil or other suitable gases or liquids may be circulated or otherwise transferred through the fluid passages to improve thermal management. Thermal management may include rapid or controlled cooling, and fluid may be circulated (e.g., through conduits formed in the temporary wall) or sprayed, dripped, or splashed onto, for example, a porous outer wall portion.

[0122] The proposed solution can be implemented in powder bed fusion additive manufacturing systems for printing metal, plastic, or ceramic parts. The application of the proposed solution can be more specifically defined as in the print bed portion of a machine with a laser or electron beam receiver. In various embodiments of this 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 for the elimination of edge walls of the chamber and allows for the creation of subset areas. The presence of subset areas / volumes / voids helps minimize powder usage and enables the production 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 handling very large objects where excess powder can constitute a large portion of the standard print volume. According to the proposed solution, powder can be selectively distributed throughout the build area within predetermined wall regions generated during the additive manufacturing process.

[0123] Because the print bed and printhead are typically vertically separated for continuous layers, a print chamber wall is needed to support the previously deposited powder layer and the printed object. One example might involve protrusions that press against the wall. Another example might involve printing a perimeter wall (and possibly structural supports for it) during each layer. This wall might be cut and recycled after each print.

[0124] In some embodiments, most or all of the peripheral walls may be raised, and walls may also be printed to reduce the powder bed area for the powder layer, while “buckets” formed by the peripheral walls are used to capture powder that falls outside the printed walls.

[0125] In some embodiments, the raised wall may not be a complete perimeter. For example, access points may be needed when the print bed is first placed into the print station and subsequently when the completed bed (powder and printed object) is lifted. Printing a finite wall in this area provides the remaining wall needed to support the powder during the print cycle. The material handling equipment may then “break through” the printed wall to gain access to the lift point. In some embodiments, the lift point may be determined by a priori algorithms or user placement and is built into the wall at a critical location.

[0126] The printed walls do not need to match the geometry of the print station, nor do they need to perfectly match the walls printed in the previous layer. This can be achieved by distributing powder sufficiently between the wall areas that require powder through appropriate powder dispensing equipment and logic. Advantageously, this can save significant amounts of time, weight, and / or powder per layer.

[0127] Figure 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 the powder bed 1120, which may be located 0.5 meters deep within a build chamber 1110. Scenario 1100 may be located at the end or middle of a printing cycle. Below the build platform 1130 is a hopper 1140 with an inclined wall, which may be at an angle of 45-60 degrees relative to the horizontal surface on which the build platform 1130 is arranged. In some embodiments, the hopper 1140 may include a auger 1150.

[0128] Figure 11B Another example scenario 1101 is shown, depicting the separation of the powder bed 1121 from the build platform 1131. Scenario 1101 may be at the end of a printing cycle or in the middle of a cycle that has been interrupted for various reasons. Inside the build chamber 1111, the build platform 1131 supporting the powder bed 1121 can be tilted from a horizontal position by more than 90 degrees. The gravitational pull caused by the weight of the powder bed 1121 causes the powder material embedded within the powder bed 1121 and the printed object to fall into the hopper 1141 below. The build chamber 1111 may include a vacuum 1160 and a high-pressure jet 1162, allowing most of the powder to be collected in the hopper 1141. After tilting the build platform 1131, suction 1160 and gas jet 1162 can be used to remove any sticky powder remaining on the build platform 1131. The hopper 1141 may have sloping walls to help guide the powder to the bottom of the hopper 1141. The hopper 1141 may include an auger 1151.

[0129] The process may involve controlling a powder dispensing assembly to dispense multiple layers of powder material to form a powder bed during a printing cycle. The vertical movement of the powder dispensing assembly can be controlled to maintain a constant separation from the powder bed. After a portion of the dispensed powder layers has bonded together, the vertical movement causes the powder dispensing assembly to rotate away from the powder bed (e.g., upwards) a distance equal to the thickness of the dispensed powder layer. To remove residual powder, the movement of the build platform may include rotation, tilting, flipping, vibrating, shaking, and / or jerking. Due to these movements, the powder bed on the build platform may fall into a hopper below the build platform due to the weight of the powder bed. Vacuum systems, robotic arms, and / or gas atomizers can be used to further remove residual powder from the build platform. Thus, a large portion of the powdered material can be collected in the hopper for reuse or storage. In some embodiments, an auger and / or conveyor may be used to transport the powder collected in the hopper toward one or more storage chambers. In another process embodiment, a large portion of the powdered material may be sealed in one or more storage chambers in an atmosphere suitable for powdered material. The atmosphere may include vacuum, air, nitrogen, argon, helium, other inert gases or rare gases.

[0130] Figure 12A and 12B A system for manufacturing long parts is illustrated. Many current 3D printers experience significant and frequent downtime when the build chamber must be emptied of powder and the printed part reset for the next print job. In the following description, a unified coordinate system 1211 is defined. Thus, certain systems may correspond to or define longitudinal, lateral, and transverse directions 1211a, 1211b, 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 1211b may be combined with the longitudinal direction 1211a to define a horizontal plane. That is, both the longitudinal and lateral directions may extend within the horizontal plane. The transverse direction 1211b may extend vertically in alignment with gravity.

[0131] In selected embodiments, the systems and methods according to the invention can enable or support substantially continuous additive manufacturing without such downtime. See also... Figure 12A and Figure 12BAs can be seen, this can be achieved by manufacturing part 1210 in segments. For example, the system can (1) manufacture the first segment 1212a of part 1210, (2) advance part 1210 a selected distance along conveyor 1216, (3) manufacture the second segment 1212b 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 cleaning (e.g., separating and / or recovering unused or uncombined particulate material) can be performed in parallel (i.e., simultaneously) at different locations or areas on the conveyor. Therefore, additive manufacturing according to the invention does not require stopping to remove particulate material and / or parts.

[0132] The system may define or include multiple zones 1236a-1236c. Different tasks may be performed in different zones. In selected embodiments, different zones may correspond to different locations along the conveyor. Accordingly, the conveyor may advance the part (e.g., translate it in the direction indicated by arrow 1232) through the various zones of the system. In some embodiments, the system may include three zones 1236a, 1236b, and 1236c. The first zone 1236a may correspond to, include, or span the portion of the conveyor where additive manufacturing takes place. Thus, the first zone 1236a may correspond to the area on the conveyor where the various layers of particulate material 144 are laid and the particulate material is kept in close contact with the part.

[0133] The second zone 1236b can directly follow the first zone 1236a. The second zone 1236b can be characterized by the movement of the unconsolidated portions of the part away from a large part. For example, in the second zone 1236b, one or more walls may terminate or be removed, such that the unconsolidated portions of the particulate material may no longer be fully contained in the lateral direction 1211b. As a result, some of the unconsolidated portions of the particulate material may overflow the side of one or more plates, conveyors, etc. The overflowed particulate material may fall into one or more containers, where it can be collected and reused.

[0134] The third zone 1236c can directly follow the second zone 1236b. The third zone 1236c is characterized in that a portion of the part 1210 within the third zone 1236c is exposed to the field of view (e.g., by removing or moving a large portion of the unmerged particulate material to expose it completely, substantially or partially to the field of view), while the part 1210 does not change its position in the lateral and transverse directions 1211b, 1211c.

[0135] For example, in some embodiments, the front portion of part 1210 may reach the third zone 1236c, while the tail portion of part 1210 remains manufactured within the first zone 1236a. Therefore, in the chosen embodiment, a 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 hold the front portion of part 1210 in the lateral and transverse directions 1211a, 1211c in the same position as the front portion occupies within the first zone 1236a and the second zone 1236b. Thus, the position of the front portion of part 1210 does not excessively interfere with, distort, etc., the additive manufacturing occurring at the tail portion of part 1210 in the first zone 1236a.

[0136] In the selected embodiment, all uncombined portions of the particulate material outside part 1210 can be removed in the second zone 1236b or in some combination of the second zone 1236b and the third zone 1236c. However, in some alternative embodiments, the bed can be removed from the conveyor while the four walls remain intact. Thus, all or some remaining uncombined portions of the particulate material can be removed at a station spaced apart from the first zone 1236a.

[0137] 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 allow the rear wall corresponding to a lower segment to be constructed higher than most of the lower segment via an additive manufacturing process, so that the rear wall can become the front wall of a subsequent higher segment. When only the rear wall is being constructed, constructing a ramp is much faster than laying a complete layer (e.g., a layer covering the entire lower segment).

[0138] The slope may comprise multiple layers of granular material whose length varies incrementally along one or more directions (e.g., longitudinal direction 1211a). For example, within the slope, the length of each successive layer may be shorter than the immediately preceding layer. The resulting slope's angle relative to the horizontal plane may be less than the critical angle of repose of the granular material. Therefore, the granular material forming the slope can be stable and will not detach or move due to gravitational acceleration acting upon it.

[0139] In operation, a first layer of particulate material particles may be distributed, and radiant energy is directed towards all particles within the first layer forming part of selected particles. A second layer of particulate material particles is distributed on top of the first layer, and radiant energy is directed towards all particles within the second layer forming part of selected particles. The first layer may define a first plane, and the second layer may define a second plane parallel to the first plane. In some embodiments, both the first and second planes are horizontal planes. In other embodiments, both the first and second planes extend relative to the horizontal plane at an angle greater than zero and less than or equal to the critical angle of repose of the particulate material, thereby forming a slope.

[0140] Figure 13A An additive manufacturing system 1300 is shown, including a powder chamber 1302 with 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 transport container, or any other desired manufacturing system component. The system 1300 also includes a robotic arm 1310 with manipulators 1312 capable of gripping a part 1330 via its additive manufacturing 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.

[0141] Although the single six-DOF robotic arm with a gripper is the manipulator shown in the figure, other automated, mechanical, or manual embodiments can be employed. For example, cranes, lifts, hydraulic arms, grippers, tracks or rails, locking mechanisms, or any other type of manually or automatically controllable manipulator can be used. The manipulator can be mounted beside, above, near, or inside the powder chamber 1302. Alternatively, the manipulator can be movably mounted above, near, or positioned on a rail within the powder chamber. In some embodiments, multiple manipulators can be used.

[0142] The manipulation device may include a position, depth, laser scanning, or similar sensor system 1314. The sensors may be mounted on or near the manipulator, in other locations on the robotic arm, or on, near, or inside the powder chamber or processing platform 1320. In some embodiments, the sensors may be movable and have hinges, rails, hydraulic pistons, or other suitable actuation mechanisms for rotating, raising, lowering, oscillating, or laterally scanning the sensors. In some embodiments, specialized depth sensors or optical edge-tracking sensing systems may be used individually or in combination with conventional RGB CMOS or CCD sensors. Options may be chosen to improve 3D positioning of parts, including the identification and use of guides, markings, or other detectable positioning markers.

[0143] Figure 13B The illustration shows about Figure 13A The described system includes a robotic arm 1310 that lifts and reorients a part 1330 via one of its additively manufactured manipulator points 1332. In some embodiments, the part 1330 may be lifted, rotated, linearly translated, and returned to a powder bed 1304 for further processing.

[0144] Figure 13C The illustration shows about Figure 13A The described system includes a robotic arm 1310 that lifts and reorients a part 1330 via one of its additively manufactured manipulator points 1332. In this embodiment, the part 1330 is lifted, rotated, and positioned onto a processing platform 1320 for further processing.

[0145] Figure 14 Part 1400 is shown, comprising various possible additively manufactured robotic manipulators. 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 function as robotic manipulators. In this figure, structure 1402 is a crescent-shaped tab with two narrow connection points to part 1400. The tab portion allows for easy engagement with a manipulator having a clamping or gripping gripper, while the narrow connection points simplify the removal of structure 1402 through mechanical cutting, sawing, punching, or drilling, or through a directed energy beam. Similarly, pin 1404 is a small protruding structure capable of engagement by a clamping or gripping gripper or by a "position" retention type engagement system that surrounds and retracts 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 of the tab after the part has been moved to the desired area / position. The plate 1408, which is relatively long and wide, is reattached at two points to simplify subsequent removal by mechanical shearing or energy beam, thus simplifying engagement via the manipulator.

[0146] 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 functionality of the part but improve the reliability of engagement with a robotic arm. For example, a prismatic locking cavity 1410 can guide a pin or clamping system to engage with the cavity. Alternatively, an unfolding jig can be used to engage a notch 1412 defined in part 1400. If desired, a cavity or opening 1416 can also be defined in a removable protrusion 1414. In some embodiments, cavities or openings in substantially additively manufactured parts can be defined by etching, drilling, punching, or removing etched material or a directed energy beam. In some other embodiments, after use, additive manufacturing techniques can be used to fill the cavities using thermoset plastics or any other suitable filling techniques.

[0147] In some embodiments, the two-dimensional or three-dimensional positioning of part 1400 can be improved by using imaging or other optical sensors that use the location of protrusions or cavities to identify the precise position of the part. In other embodiments, a marker light guide or marker 1420 can be additively formed or mechanically or laser-engraved on the protrusion structure or the part itself to improve guidance for engagement 3D positioning after movement.

[0148] In one embodiment, processing can be performed via the following steps. In the first step, material is placed on a powder bed within a powder chamber. Then, a part comprising one or more manipulator points is fabricated using a directional beam of two-dimensional patterned energy. A manipulator can engage the manipulator 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 manipulator points can be removed (e.g., protruding tabs are mechanically trimmed) or filled (e.g., additively defined holes or epoxy-filled cavities).

[0149] Figure 15An example process 1500 is shown for collecting and characterizing powder samples of powder material during a printing process. Process 1500 can be used to collect powder samples from a powder bed or powder dispensing assembly and to characterize the powder samples in real time in a test suite according to this disclosure. At 1510, process 1500 may involve controlling a collector during a printing cycle to collect multiple powder samples of powder material as the printed object is formed. The powder material may include metal, ceramic, plastic powder, or other suitable powders capable of bonding together when subjected to heat. The collector may collect powder samples at predetermined intervals or randomly, or periodically at predetermined stages of 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 is completed. The collector may have a mechanism for transferring powder from the powder bed or powder dispensing assembly. The collector may also control the amount of powder transferred, depending on how many tests are needed for analysis. At 1520, process 1500 may involve controlling a test suite to perform one or more tests. In some embodiments, one or more specific properties of the powder material may need to be strictly controlled within certain ranges to ensure the mechanical, electrical, or optical properties of the printed object. In other embodiments, it may be necessary to preserve the powder properties during the printing process for auditing purposes. The test kit may include instruments capable of performing one or more tests. For illustrative purposes without limitation, one test may measure the distribution of powder size using a particle size analyzer; a second test may measure the density of the powder sample using a hydrometer; and a third test may identify substances within the powder sample using gas chromatography-mass spectrometry. At 1530, process 1500 may involve determining whether to modify a set of printing parameters used in the printing process or whether to abort the printing process based on the characteristics of the test results. This determination may include computer simulation based on a set of models using the results of characterization as input. Uncertified or poorly processed powder samples may undergo undesirable powder changes. Tests can provide real-time feedback on the powder properties during the printing process. One or more printing parameters may be modified based on the test results. For example, the incident beam intensity may be increased or decreased when a gas hydrometer measures a deviation in a specific powder density that may affect the energy per unit volume required to melt or sinter the powder. The residence time of the incident jet provided by the printhead or the thickness of the powder layer distributed by the powder dispensing assembly can also be controlled to adjust for variations in energy demand. If the energy per unit volume deviates too much from the specified powder density, the printing process may stop or abort because the energy within the printhead 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, the printing process can be stopped if the characterization results indicate the use of unlicensed or hazardous powders (including unlicensed powders that may lead to poor additive manufacturing results).

[0150] In some embodiments, predicting the final print quality based on the results of in-process (real-time or in-situ) characterization of the powder sample can be performed through simulation using a set of models. For example, the dimensional control of the printed object can depend on the resolution of the incident beam and the temperature gradient of the powder at the boundary of the molten region. If the temperature does not drop rapidly enough at the boundary and causes the molten region to exceed the dimensional tolerances, the molten region may extend beyond the expected boundary. The temperature gradient can be simulated using a heat transfer model that calculates thermal conductivity based on the properties of the powder, such as its composition and size. If the simulated model predicts that the dimensions of the printed object exceed the dimensional tolerances, the printing process can be aborted.

[0151] At 1540, process 5100 may involve storing powder samples in multiple sample containers. These containers may be used for analyses that may not be suitable for in-process characterization or for later review purposes. The storage containers may be able to package the powder samples in an atmosphere substantially identical to the in-process (real-time or in-situ) atmosphere inside the sample containers. This atmosphere may be a vacuum, air, or an inert gas such as nitrogen, carbon dioxide, argon, helium, or other rare gases.

[0152] refer to Figure 16 The manufacturing facility 1624 according to the invention may include one or more machines 1610 housed within a housing 1626. Such a housing 1626 may control one or more environmental conditions as needed or necessary. For example, the housing 1626 may protect the printing or the material to be printed from undesirable thermal, chemical, photonic, radiation, or electronic reactions or interactions, or combinations thereof. The housing 1626 may also protect human operators 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.

[0153] One or more machines 1610 contained within a specific housing 1626 may all have the same or different dimensions. Similarly, one or more machines 1610 contained within a specific housing 1626 may all be of the same or different types. For example, in a selected embodiment, each of the one or more machines 1610 within housing 1626 may combine (e.g., join, bond, melt, sinter, thaw, etc.) a specific particulate material in a batch process. In other embodiments, each of the one or more machines 1610 within housing 1626 may combine a specific particulate material in a continuous process. In other embodiments, one or more machines 1610 within housing 1626 may combine a specific particulate material in a batch process, while one or more other machines 1610 within housing 1626 may combine a specific particulate material in a continuous process.

[0154] In some embodiments, manufacturing facility 1624 may include one or more airlocks 1628 forming one or more antechas for respective housings 1626. Airlocks 1628 allow parts, materials 144, personnel, etc., to enter and exit housings 1626 without compromising the environment within housings 1626 (e.g., a low-oxygen and inert gas environment). Airlocks 1628 may include at least two airtight (or substantially airtight) doors 1630a, 1630b. A first door 1630a of airlock 1628 allows parts, materials 144, personnel, etc., to pass between the interior of airlock 1628 and the interior of the respective housing 1626. A second door 1630b allows parts, materials 144, personnel, etc., to pass between the interior of airlock 1628 and the external environment surrounding the respective housing 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 compatible with the interior of the housing 1626 and a state compatible with the environment outside the housing 1626.

[0155] One or more machines 1610 can be arranged within the housing 1626 such that sufficient space is reserved around the machines 1610 for one or more human workers, robots, etc., to access the machines 1610, remove parts from them, vacuum remove unconsolidated particulate material 144 for reuse, etc. Alternatively or additionally, the housing 1626 may include various racks, construction walkways, etc., that allow one or more human workers, robots, etc., to access the machines 1610 from above (e.g., visual access, physical access). This can be helpful when the housing 1626 contains one or more large machines 1610, where access from their edges or sides may be insufficient to perform certain tasks.

[0156] In some embodiments, manufacturing facility 1624 may include one or more gas management systems 1632 that control the composition of gaseous substances within housing 1626. Gas management system 1632 may maintain the concentration of inert or substantially inert gases (e.g., vacuum, nitrogen, argon, carbon dioxide, etc., or combinations thereof or sub-combinations thereof) above a desired level (e.g., argon volume at or above about 99.9%). Optionally, 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 volume may be below 0.05%, and the water vapor volume may be below 0.05%.

[0157] The gaseous environment within the enclosure 1626 may be incompatible with the breathing 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 invention, one or more workers may wear personal protective equipment (PPE). Subsequently, when workers enter the enclosure 1626, the PPE can create a barrier between the workers within the enclosure 1626 and the working environment.

[0158] 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-loop device (e.g., a ventilator) that filters, replenishes, recovers, or stores exhaled gases. Alternatively, the SCBA may be an open-loop device that releases at least some exhaled gases (e.g., nitrogen, carbon dioxide, oxygen, water vapor, or combinations or sub-combinations thereof) into the surrounding environment. In embodiments using an open-loop device, the amount exhaled by one or more workers within the housing 1626 may be very small relative to the excessive size of the housing 1626. Therefore, the release of oxygen, water vapor, etc., into 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).

[0159] refer to Figure 17In the selected embodiment, the manufacturing facility may include multiple work areas 1724 connected via 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 may therefore not be contained within a single housing. One or more work areas 1724 forming such a network 1740 may be contained within one or more buildings. For example, in the selected embodiment, all the various work areas 1724 forming the network 1740 may be contained within a single building. In such an embodiment, any work area 1724 contained within the housing 1726 may be a work area 1724 requiring more environmental conditioning than the environmental conditioning provided by the building.

[0160] Various work areas 1724 of network 1740 may be defined and / or arranged to correspond to certain manufacturing-related processes. Such processes may include creating parts by additive manufacturing; removing parts from the machine that created the parts; removing uncombined particulate material; separating parts from a base or bed, one or more support structures (e.g., external portions extending through one or more traveling walls of the part, printed to support the parts during additive manufacturing, one or more temporary structures that will not be included in the finished part, etc.); heat treatment; shot peening; powder coating, painting, anodizing, etc.; shipping and packaging; or the like or combinations or sub-combinations thereof.

[0161] For example, in a selected embodiment, network 1740 may include a first working area 1724a for powder bed melting 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 polishing in housing 1726, a fourth working area 1724d for heat treatment 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 transportation, etc., or combinations or sub-combinations thereof.

[0162] 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 different sizes. Similarly, these one or more machines may all be of the same type or different types. For example, in a selected embodiment, each of the one or more machines within the housing 1726 may combine (e.g., join, bond, melt, sinter, thaw, etc.) a specific particulate material in a batch process. In other embodiments, each of the one or more machines within the housing may combine a specific particulate material in a continuous process. In other embodiments, one or more machines within the housing may combine a specific particulate material in a batch process, while one or more other machines within the housing may combine a specific particulate material in a continuous process.

[0163] One or more machines in the first work area 1724a can be arranged such that sufficient space is reserved around the machines for one or more human workers, robots, etc., to access the machines, remove parts from them, vacuum remove uncombined particulate material for reuse, etc. Alternatively or additionally, the first work area 1724a may include various racks, construction walkways, etc., that allow one or more human workers, robots, etc., to access the machines from above (e.g., visual access, physical access). This can be helpful when the first work area 1724a contains one or more large machines where access from their edges or sides may be insufficient to perform certain tasks.

[0164] In the second working area 1724b, uncombined 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., moving) collection port can be used to collect uncombined particulate material from around the part, away from the build platform or bed, etc. Alternatively or in addition, one or more streams of pressurized gas, manually or robotically controlled (e.g., aiming), can be used to remove uncombined particulate material from certain cracks, sweep uncombined particulate material from the build platform or bed, and / or move uncombined particulate material to one or more locations accessible by vacuum.

[0165] In the selected embodiment, as shown in the figure, the first working area 1724a and the second working area 1724b may be contained within a separate housing 1726. In other embodiments, the first working area 1724a and the second working area 1724b may be contained within the same housing 1726. Furthermore, in some embodiments, the first working area 1724a and the second working area 1724b may geographically overlap to at least some extent, but may be temporally spaced (e.g., one or more tasks corresponding to one working area 1724a may be executed at a different time than one or more tasks corresponding to the other working area 1724b).

[0166] Optionally, the first and second work areas 1724a and 1724b may be geographically adjacent to each other, but may overlap to some extent in time (e.g., one or more tasks corresponding to one work area 1724a may be executed at the same time as one or more tasks corresponding to the other work area 1724b). In such an embodiment, the first area of ​​the machine may correspond to or be the first work area 1724a, and the second area (or a combination of the second and third areas) may correspond to or be the second work area 1724b.

[0167] In the third working area 1724c, the shot peening process can be applied manually or robotically to one or more parts. For example, in selected embodiments, a manual or robotic system can use the same particulate material as the impact medium in the shot peening process (i.e., the same particulate material used to create the parts) to improve the surface polishing of the parts.

[0168] In the fourth working area 1724d, the housing 1726 may be or include an oven for heat treating one or more parts. Therefore, such a housing 1726 can be configured to generate, retain, and control a large amount of heat. The exact amount of heat can vary between the dimensions of the housing 1726, the nature of the parts being heat treated, etc.

[0169] In the fifth work area 1724e, one or more build platforms or beds may be detached from the parts they support; one or more external portions extending through one or more travel walls of the part may be removed; one or more temporary structures printed to support the part during additive manufacturing that will not be included in the finished part may be removed, or combinations thereof. In selected embodiments, this may involve a wire electrical discharge machining (EDM) process. In such embodiments, the part may be immersed in a bath of partially deionized water, where the ion content is carefully controlled as part of the EDM process. A housing for the fifth work area 1724e may be included or omitted as needed or necessary.

[0170] In the sixth work area 1724f, one or more parts may be prepared for shipment and / or be 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 needed or necessary.

[0171] In the selected embodiment, network 1740 may include a plurality of work areas 1724 connected in series by one or more interface mechanisms 1728. Such interface mechanisms 1728 enable one or more parts to flow smoothly and efficiently from one work area 1724 to the next. Accordingly, work areas 1724 may be arranged in network 1740 such that the tasks associated with them can be performed in a required or desired order.

[0172] Any of the enclosures may maintain the concentration of an inert gas or substantially inert gas (e.g., vacuum, nitrogen, argon, carbon dioxide, etc., or combinations thereof or sub-combinations thereof) above a desired level (e.g., argon volume at or above about 99.9%). Alternatively or in addition, the enclosures may maintain the concentration of oxygen and / or water vapor below atmospheric levels (e.g., gaseous oxygen volume below 0.05%, water vapor volume below 0.05%).

[0173] Printing beds, parts, or other materials can be transported via interface mechanism 1728 using a vehicle by rolling or otherwise moving on a path (e.g., a concrete floor), a conveying system, rails, or a combination of rails using a conventional railway concept; linear movement on a track using an encoder; linear movement provided by a pulley system; movement and / or levitation provided by a magnetic levitation track; movement via a conveyor system or conveyor belt, etc., or combinations or sub-combinations thereof. Large parts weighing 2,000 kg or more can be transported. The vehicle may have wheels that roll on a supporting surface. The supporting surface may be a floor (e.g., a floor with visually, electronically, or magnetically detectable paths applied to or embedded therein). The supporting surface may also be one or more rails. Such rails may be located below the parts carried by the vehicle. Alternatively, these rails may be located above the parts carried by the vehicle. That is, the rails may be elevated rails, and the vehicle may be a trolley or tram that rolls on the elevated rails while suspending the parts below them.

[0174] Wheeled or other vehicles can be controlled and / or operated manually, automatically, autonomously, or semi-autonomously. For example, in selected embodiments, one or more wheeled vehicles can be pushed and / or manipulated by one or more human operators. In other embodiments, various on-board or off-board control systems can sense what is happening to the vehicle and instruct when the vehicle moves, when it stops, how it is driven, etc.

[0175] Many modifications and other embodiments of the invention will arise for those skilled in the art upon which the teachings presented in the foregoing description and associated drawings will come to mind. Therefore, it should be understood that the scope of the invention is not limited to the specific examples of the disclosed embodiments, and that modifications and embodiments are intended to be included within the scope of the appended solutions. It should also be understood that other embodiments of the invention may be practiced without the elements / steps specifically disclosed herein.

Claims

1. An additive manufacturing system, comprising: A high-energy photon source, the high-energy photon source being configured to generate a beam; A reflective patterning unit, the reflective patterning unit being configured to receive the beam and reflect a two-dimensional patterned beam; and An image repeater configured to receive the two-dimensional patterned beam and focus the two-dimensional patterned beam as a two-dimensional image onto a powder bed.

2. The additive manufacturing system according to claim 1, wherein, The high-energy photon source includes multiple semiconductor lasers.

3. The additive manufacturing system according to claim 1, wherein, The reflective patterning unit is optically addressed.

4. The additive manufacturing system according to claim 1, wherein, The reflective patterning unit includes a high-transmittance layer, a twisted nematic (TN) liquid crystal layer, and a photoconductor layer.

5. The additive manufacturing system according to claim 1, wherein, The reflective patterning unit is cooled.

6. The additive manufacturing system according to claim 1, further comprising: The powder bed is configured to hold the powdered material.

7. An additive manufacturing apparatus, comprising: Multiple lens assemblies, each including an interchangeable portion, are configured to provide multiple magnifications that proportionally increase or decrease the size of the image of the incident light. as well as An electromechanical component configured to select one of the lens assemblies to provide one of the magnifications, so as to convert a first image of the incident light into a second image of the incident light according to the one of the magnifications.

8. The additive manufacturing apparatus according to claim 7, wherein, The electromechanical components include a shape-changing dynamic lens, an electronic lens exchange system, a beam redirection system, a photoelectric controlled refractive beam orientation device, or a combination thereof.

9. The additive manufacturing apparatus according to claim 7, further comprising: Powder bed; Build platform racks; as well as A final beam-directing device, mounted on the build platform frame and configured to guide the incident light emitted from one or more of the lens assemblies, such that a second image of the incident light is formed at the location of the powder bed holding the powdered material and supported by the build platform frame.

10. The additive manufacturing apparatus according to claim 9, further comprising: One or more sets of compensation racks; as well as A processor configured to control the plurality of lens assemblies, the electromechanical components, the powder bed, the build platform frame, the final beam directional device, and one or more sets of compensation frames to perform operations including: Information about one of the magnifications and the image distance is obtained during a 3D printing job; the image distance is related to the intensity of incident light on the top surface of the powder bed and the pixel size. as well as One of the plurality of lens assemblies is configured to provide incident light having said one of the magnifications, wherein the lens assembly includes a plurality of first sets of optical lenses and a plurality of second sets of optical lenses, and wherein the second sets of optical lenses are interchangeable from said lens assembly.

11. The additive manufacturing apparatus according to claim 10, wherein, The processor is also configured to control the plurality of lens assemblies, the electromechanical components, the powder bed, the build platform frame, the final beam directional device, and one or more sets of compensation frames to perform operations including the following: Multiple rotations are performed on one or more sets of mirrors mounted on one or more sets of compensation frames and on a last set of mirrors mounted on the build platform frame to guide the incident light from the precursor image to a position on the final image plane on the top surface of the powder bed; as well as Multiple translational movements are performed on the one or more sets of compensation frames and the build platform frame to control the distance of the incident light from the initial image position to the position on the top surface of the powder bed, so as to substantially maintain the image resolution at the desired position.

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