Contourless melt pool control

Abstract

The techniques described herein relate to controlling a geometry of melt pools in additive manufacturing systems. An example method comprises directing laser energy from laser energy source(s) through an optics assembly and toward a build surface; melting at least a portion of a layer of material on the build surface due to exposure of the portion to the laser energy; and controlling a geometry of melt pools at end portions of scanning trajectories followed by the laser energy source(s), a first scanning trajectory of the scanning trajectories including one or more first scans in a first scanning orientation and a second scanning trajectory of the scanning trajectories including one or more second scans in a. second scanning orientation. Controlling the geometry of melt pools comprises controlling parameter(s) of the laser energy source(s) at end portions of the first scan(s) and at end portions of the second scan(s).

Description

CONTOURLESS MELT POOL CONTROL CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority under U.S.C. § 119(e) of U.S. Provisional Application Serial No. 63 / 510,175, filed June 26, 2023, the disclosure of which is incorporated herein by reference in its entirety. FIELD

[0002] Disclosed embodiments are generally related to additive manufacturing systems and, more particularly, to melt pool control in additive manufacturing systems. BACKGROUND

[0003] Additive manufacturing systems employ various techniques to create three- dimensional objects from two-dimensional layers. Powder bed fusion processes are an example of additive manufacturing processes in which a three-dimensional shape is formed by selectively joining material in a layer-by-layer process. In metal powder bed fusion processes, one or more laser beams are scanned over a thin layer of metal powder. If the various laser parameters, such as laser power, laser spot size, and / or laser scanning speed are in a regime in which the delivered energy is sufficient to melt the particles of metal powder, one or more melt pools may be established on a build surface. The laser beams are scanned along predefined trajectories such that solidified melt pool tracks create shapes corresponding to a two-dimensional slice of a three-dimensional printed part. After completion of a layer, the powder surface is indexed by a defined distance, the next layer of powder is spread onto the build surface, and the laser scanning process is repeated. The layer indexing and scanning is repeated multiple times until a desired three-dimensional shape is fabricated. SUMMARY

[0004] Some embodiments relate to an additive manufacturing system comprising a build surface; one or more laser energy sources; an optics assembly movable relative to the build surface and configured to direct laser energy from the one or more laser energy sources 12486774.1toward the build surface to melt at least a portion of a layer of material disposed on the build surface; and a controller operatively coupled to the optics assembly and configured to: control a geometry of melt pools at end portions of scanning trajectories followed by the one or more laser energy sources, a first scanning trajectory of the scanning trajectories including one or more first scans in a first scanning orientation and a second scanning trajectory of the scanning trajectories including one or more second scans in a second scanning orientation, wherein to control the geometry of melt pools the controller is further configured to: control one or more parameters of the one or more laser energy sources at end portions of the one or more first scans in the first scanning orientation and at end portions of the one or more second scans in the second scanning orientation.

[0005] Some embodiments relate to a method for additive manufacturing. The method comprises directing laser energy from one or more laser energy sources through an optics assembly and toward a build surface; melting at least a portion of a layer of material on the build surface due to exposure of the portion to the laser energy; and controlling a geometry of melt pools at end portions of scanning trajectories followed by the one or more laser energy sources, a first scanning trajectory of the scanning trajectories including one or more first scans in a first scanning orientation and a second scanning trajectory of the scanning trajectories including one or more second scans in a second scanning orientation, wherein controlling the geometry of melt pools comprises: controlling one or more parameters of the one or more laser energy sources at end portions of the one or more first scans in the first scanning orientation and at end portions of the one or more second scans in the second scanning orientation.

[0006] Some embodiments relate to at least one non-transitory computer-readable medium storing instructions, that when executed by at least one processor, cause the at least one processor to perform a method of additive manufacturing. The method comprises directing laser energy from one or more laser energy sources through an optics assembly and toward a build surface; melting at least a portion of a layer of material on the build surface due to exposure of the portion to the laser energy; and controlling a geometry of melt pools at end portions of scanning trajectories followed by the one or more laser energy sources, a first scanning trajectory of the scanning trajectories including one or more first scans in a first scanning orientation and a second scanning trajectory of the scanning trajectories including 12486774.1one or more second scans in a second scanning orientation, wherein controlling the geometry of melt pools comprises: controlling one or more parameters of the one or more laser energy sources at end portions of the one or more first scans in the first scanning orientation and at end portions of the one or more second scans in the second scanning orientation.

[0007] It should be appreciated that the foregoing concepts, and additional concepts discussed below, may be arranged in any suitable combination, as the present disclosure is not limited in this respect. Further, other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non- limiting embodiments when considered in conjunction with the accompanying figures. BRIEF DESCRIPTION OF DRAWINGS

[0008] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:

[0009] FIG. 1 shows a schematic representation of an additive manufacturing system according to some embodiments;

[0010] FIG. 2 shows the optical paths present in an additive manufacturing system according to some embodiments;

[0011] FIG. 3 shows an additive manufacturing system according to some embodiments;

[0012] FIG. 4 shows a three-dimensional (3D) part printed using a two-phase process, where bulk melt pool tracks are generated during the first phase and a contouring technique is applied in the second phase;

[0013] FIG. 5 is a block diagram of an exemplary build plan generation system including a process controller, according to some embodiments;

[0014] FIG. 6 shows an example scanning trajectory including multiple scans, according to some embodiments;

[0015] FIG. 7 shows an example scanning trajectory including first scan(s) in a first scanning orientation for one layer and second scan(s) in a second scanning orientation for another layer; according to some embodiments; 12486774.1

[0016] FIG. 8 illustrates multiple end portions along a scanning trajectory, according to some embodiments;

[0017] FIG. 9 shows controlling power levels during a scan, according to some embodiments;

[0018] FIG. 10 is a diagram of a process for generating a build plan for controlling additive manufacturing where melt pool geometry of end portions of the first and second scan(s) is controlled, according to some embodiments; and

[0019] FIG. 11 is an example electronic platform structured to execute the machine- readable instructions of FIG. 10 to implement the exemplary process controller of FIG. 5 and / or, more generally, the exemplary additive manufacturing system of FIG. 5, according to some embodiments. DETAILED DESCRIPTION

[0020] Some additive manufacturing systems may iteratively melt and / or fuse selective portions of sequential layers of precursor material to build a product from the fused material. For example, some laser powder bed fusion (LPBF) additive manufacturing systems may use lasers to melt and / or fuse portions of sequential layers of a precursor material such as a powdered metal, plastic, polymer, or other material. The melted portions of the precursor material may be referred to as melt pools. Such melt pools fuse the precursor material in desired areas to form the desired two-dimensional structure for a given layer, and thus a three-dimensional structure (e.g., a 3D part) when the fused portions of different layers are joined together. Melt pools can be formed by exposing the precursor material to laser or other light energy of sufficient power to melt the precursor material in a local area. The path followed by the laser as the laser scans across the precursor material during each scanning pass, along with the resulting melt pools, forms a series of melt pool tracks. Some factors that can affect the melt pool geometry include, hatch spacing, laser power, laser scanning speed, and other processing parameters.

[0021] Surface roughness is considered as one of the quality factors of 3D parts printed using the LPBF process. In particular, the quality of a 3D printed part deteriorates due to lack of fusion defects that are caused when adjacent layers of the 3D part do not join adequately resulting in gaps within the 3D part and / or edges of the 3D part. Contouring 12486774.1techniques are typically incorporated in the LPBF process to refine or improve the surface roughness or uniformity of the 3D part by lasing the edge of the 3D part such that the laser scan closely flows the contours of the part geometry. Lasing the edge of the 3D part smooths out the surface of the 3D part by reducing lack of fusion defects at the edges of the 3D part. This contouring technique is different than and is performed separately from the bulk laser events that traverse the inside of the geometry to print the internal structure of the 3D part.

[0022] The inventors have recognized that although contouring techniques can improve the surface roughness of the 3D part, these techniques are time consuming and add to the printing time of the 3D part, and hence are not adaptable for scaling up or mass production. This is because contouring is performed after the 3D part is printed and adds an additional laser scan phase to the LPBF process. For instance, a first phase of the LPBF process includes the bulk laser events where the laser beam scans across each layer of the precursor material and melts the powder particles to create the desired structure. The second phase of the LPBF process includes applying contouring techniques to smooth the edges of the structure. Performing this second contouring phase in addition to the first phase significantly adds to the printing time of the 3D part. FIG. 4 illustrates a 3D part, for example a square 3D part, printed using the two-phase process, where bulk melt pool tracks 402 are generated during the first phase and a contouring technique is applied in the second phase where the laser scan follows the contour 404 (e.g., all sides / edges) of the square 3D part.

[0023] Selection of appropriate processing parameters for the LPBF process, such as for example, laser scanning speed, laser power, and / or other parameters, is not a trivial task. Improper selection of processing parameters may cause defects such as high surface roughness – rougher surface quality, deformation, and lack of fusion, which deteriorate the quality of a 3D printed part. Introducing a second phase in the LPBF process means that the selection of the processing parameters needs to be performed twice, once for the first phase and then again for the second phase. Selection of processing parameters for the second phase can be even more complex and time consuming than the first phase because of the precise control required for the laser scan to closely follow the contour of the 3D part.

[0024] To address these challenges, the inventors have developed an improved LPBF process that produces a quality printed 3D part (e.g., a printed 3D part with improved surface roughness or uniformity) without requiring a separate contouring phase. Removal of the 12486774.1contouring phase from the LPBF process reduces the printing time of the 3D part and eliminates the complex and time-consuming processing parameter selection for the contouring phase. The inventors have recognized that adjusting the shape and / or size of the melt pools at end portions disposed along a scanning trajectory during the bulk laser scanning phase (i.e., the first phase described above) eliminates the need for the contouring phase (i.e., the second phase described above). In some embodiments, this adjustment to the melt pool geometry may be achieved by changing the power level of the light energy applied to the precursor material at the end portions. For instance, the power level of the light energy may be increased at the end portions causing the melt pool geometry to change at these end portions resulting in reduced lack of fusion defects without requiring a separate contouring phase.

[0025] In some embodiments, laser energy from one or more laser energy sources is directed onto a build surface to form one or more laser energy spots (i.e., pixels) on the build surface. The LPBF process may include arranging incident laser spots on a build surface in a line with a long dimension and a short dimension, or in an array. In either case, according to some aspects, a line, or array, of incident laser energy consists of multiple individual laser energy pixels arranged adjacent to each other that can have their respective power levels individually controlled. Each laser energy pixel may be turned on or turned off independently and the power of each pixel can be independently controlled. The resulting pixel-based line or array may then be scanned across a build surface to form a desired pattern thereon by controlling the individual pixels during translation of the optics assembly.

[0026] Depending on the particular embodiment, an additive manufacturing system according to the current disclosure may include any suitable number of laser energy sources. For example, in some embodiments, the number of laser energy sources may be at least 5, at least 10, at least 50, at least 100, at least 500, at least 1,000, at least 1,500, or more. In some embodiments, the number of laser energy sources may be less than 2,000, less than 1,500, less than 1,000, less than 500, less than 100, less than 50, or less than 10. Additionally, combinations of the above-noted ranges may be suitable. Ranges both greater and less than those noted above are also contemplated as the disclosure is not so limited.

[0027] Additionally, in some embodiments, a power output of a laser energy source (e.g., a laser energy source of a plurality of laser energy sources) may be between about 50 W 12486774.1and about 2,000 W (2 kW). For example, the power output for each laser energy source may be between about 100 W and about 1.5 kW, and / or between about 500 W and about 1 kW. Moreover, a total power output of the plurality of laser energy sources may be between about 500 W (0.5 kW) and about 4,000 kW. For example, the total power output may be between about 1 kW and about 2,000 kW, and / or between about 100 kW and about 1,000 kW. Ranges both greater and less than those noted above are also contemplated as the disclosure is not so limited.

[0028] Depending on the embodiment, an array of laser energy pixels (e.g., a line array or a two-dimensional array) may have a uniform power density along one or more axes of the array including, for example, along the length dimension (i.e. the longer dimension) of a line array. In other instances, an array can have a non-uniform power density along either of the axes of the array by setting different power output levels for each pixel’s associated laser energy source. Moreover, individual pixels on the exterior portions of the array can be selectively turned off or on to produce an array with a shorter length and / or width. In some embodiments, the power levels of the various pixels in an array of laser energy may be independently controlled throughout an additive manufacturing process. For example, the various pixels may be selectively turned off, on, or operated at an intermediate power level to provide a desired power density within different portions of the array.

[0029] Generally, laser energy produced by a laser energy source has a power area density. In some embodiments, the power area density of the laser energy transmitted through an optical fiber is greater than or equal to 0.1 W / micrometer2, greater than or equal to 0.2 W / micrometer2, greater than or equal to 0.5 W / micrometer2, greater than or equal to 1 W / micrometer2, greater than or equal to 1.5 W / micrometer2, greater than or equal to 2 W / micrometer2, or greater. In some embodiments, the power area density of the laser energy transmitted through the optical fiber is less than or equal to 3 W / micrometer2, less than or equal to 2 W / micrometer2, less than or equal to 1.5 W / micrometer2, less than or equal to 1 W / micrometer2, less than or equal to 0.5 W / micrometer2, less than or equal to 0.2 W / micrometer2, or less. Combinations of these ranges are possible. For example, in some embodiments, the power area density of the laser energy transmitted through the optical fiber is greater than or equal to 0.1 W / micrometer2and less than or equal to 3 W / micrometer2. 12486774.1

[0030] Depending on the application, output of the optics assembly may be scanned across a build surface of an additive manufacturing system in any appropriate fashion. For example, in one embodiment, one or more galvo scanners may be associated with one or more laser energy sources to scan the resulting one or more laser pixels across the build surface. Alternatively, in other embodiments, an optics assembly may include an optics head that is associated with one or more appropriate actuators configured to translate the optics head in a direction parallel to a plane of the build surface to scan the one or more laser pixels across the build surface. In either case, it should be understood that the disclosed systems and methods are not limited to any particular construction for scanning the laser energy across a build surface of the additive manufacturing system.

[0031] For the sake of clarity, transmission of laser energy through an optical fiber is described generically throughout. However, with respect to various parameters such as transverse cross-sectional area, transverse dimension, transmission area, power area density, and / or any other appropriate parameters related to a portion of an optical fiber that the laser energy is transmitted through, it should be understood that these parameters refer to either a parameter related to a bare optical fiber and / or a portion of an optical fiber that the laser energy is actively transmitted through such as an optical fiber core, or a secondary optical laser energy transmitting cladding surrounding the core. In contrast, any surrounding cladding, coatings, or other materials that do not actively transmit the laser energy may not be included in the disclosed ranges.

[0032] In some embodiments, an LBPF process may include selectively melting a metal powder bed by an energy heat source, such as a laser beam, in a layer-by-layer manner based on a designed scanning strategy to produce final parts. A designed scanning strategy, which may be referred to as a build plan, or portion(s) thereof, may include one or more parameters. Parameters herein may also be referred to as build plan parameters, LBPF parameters, LBPF processing parameters, or processing parameters and are interchangeable. Non-limiting examples of a parameter may include but not limited to locations of the plurality of laser energy pixels on the build surface during the build process, trajectories of the laser energy pixels across the build surface, a list of the operating parameters for the laser energy pixels, expected intensity values of laser energy pixels projected onto the build surface, the expected radiation emissions and / or reflections of welds and / or melt pools 12486774.1(expected weld signature), and / or other appropriate parameters. These commanded parameters for each laser energy pixel may then be compared to the corresponding parameters in the image for the corresponding laser energy pixel of the plurality of laser energy pixels to identify an operating state of each laser energy pixel that is currently being operated. Build plans may alternatively or additionally include parameters for one or more lasers of the additive manufacturing system, such as, laser power, scanning speed, spot size, hatch spacing, or one or more other parameters of the one or more lasers.

[0033] As used herein, the term build plan and other similar terms may refer to the planned paths, e.g., scanning trajectories, traced by the energy sources in the additive manufacturing process, including the thickness of each build layer, to form the plurality of build layers of one or more parts on a build plate. A build plan may include scanning trajectories for various laser energy pixels for multiple layers that will be scanned in different directions. Build plans may alternatively or additionally include other information such as a list of functional laser energy sources, the intensities at which the energy sources may operate at different locations along the build surface in each layer, a velocity of the optics assembly and laser energy pixels relative to a build surfaces, locations of laser energy pixel on the build surface during a build process, and other appropriate processing parameters. The paths traced by the one or more laser energy sources and / or laser energy pixels, referenced as trajectories, may be determined prior to the start of the manufacturing process and / or may be generated or updated in real time in instances where real time planning is implemented for an additive manufacturing process. In some embodiments, processing parameters may be associated with individual layers of the build plan, such as energy source intensity, and may be adjusted during a build process. For example, a build plan may include per-layer build information which may be used to monitor the status of a part. Per-layer build information may include an expected build pattern during and / or after each layer is printed, expected dimensions of the part after each layer is printed, and any other applicable build information. Furthermore, a build plan may include parameters representing specific energy source power settings, weld or formation speed, recoating rates, expected laser energy pixel shapes and / or sizes, expected weld pool shapes and / or sizes, and / or other process related information. The various processing parameters, including power settings and weld or formation speed, may be actively changed during a build based on the measured information associated with the 12486774.1different laser energy pixels. In some embodiments, processing parameters, such as the expected locations of the plurality of laser energy pixels, may be obtained independently from a weld pattern and / or build plan. Additionally, some processing parameters, such as the commanded locations of the laser energy pixels on the build surface, may be calculated from other information present in the build plan, including laser energy source trajectories, operation timing, timing, and any other applicable information.

[0034] The build plan may be obtained from a build plan generation system configured to generate the build plan, or the build plan may be uploaded to the additive manufacturing system, recalled from non-transitory computer readable memory, or obtained in any other appropriate manner. In some embodiments, the build plan may include processing parameters about the build process such as trajectory, timing, power, velocity, travel path, dimensions of the part and / or build surface, weld pattern, and / or expected locations and / or timing of the plurality of laser energy pixels firing on the build surface. In other embodiments, a build plan may not include an expected weld pattern and / or locations of the laser energy pixels but may include other processing parameters which can be used to obtain expected locations of the plurality of laser energy pixels and / or an expected weld pattern. For example, from the timing of the firing of the plurality of laser energy sources, velocity of the optics assembly, and direction of travel, an expected weld pattern may be determined. Furthermore, in some embodiments, the expected weld pattern and / or expected locations of the plurality of laser energy pixels versus time may be obtained independently from a build plan. For example, the expected weld pattern and / or expected locations of the plurality of laser energy pixels may be directly imported and / or inputted into the additive manufacturing system.

[0035] It will be appreciated that any embodiments of the systems, components, methods, and / or programs disclosed herein, or any portion(s) thereof, may be used to form any part suitable for production using additive manufacturing. For example, a method for additively manufacturing one or more parts may, in addition to any other method steps disclosed herein, include the steps of selectively fusing one or more portions of a plurality of layers of precursor material deposited onto the build surface to form the one or more parts. This may be performed in a sequential manner where each layer of precursor material is deposited on the build surface and selected portions of the upper most layer of precursor 12486774.1material is fused to form the individual layers of the one or more parts. This process may be continued until the one or more parts are fully formed.

[0036] Turning to the figures, specific non-limiting embodiments are described in further detail. It should be understood that the various systems, components, features, and methods described relative to these embodiments may be used either individually and / or in any desired combination as the disclosure is not limited to only the specific embodiments described herein.

[0037] FIG. 1 shows, according to some embodiments, a schematic representation of an additive manufacturing system 100, including a plurality of laser energy sources 102 that deliver laser energy to an optics assembly 104 positioned within a machine enclosure 106. For example, the machine enclosure may define a build volume in which an additive manufacturing process may be carried out. In particular, the optics assembly may direct laser energy 108 towards a build surface 110 positioned within the machine enclosure to selectively fuse powdered material on the build surface. As described in more detail below, the optics assembly 104 may include a plurality of optics defining an optical path within the optics assembly that may transform, shape, and / or direct laser energy within the optics assembly such that the laser energy is directed onto the build surface as an array of laser energy pixels. In some embodiments, the optics assembly may be movable within machine enclosure 106 to scan laser energy 108 across build surface 110 during a manufacturing process. For example, the optics assembly may be associated with appropriate actuators, rails, motors, and / or any other appropriate structure capable of optics assembly relative to the surface. Alternatively, embodiments in which the optics assembly includes galvomirrors or other appropriate components that are configured to scan the laser energy 108 across the build surface while the optics assembly is held stationary relative to the build surface are also contemplated.

[0038] In some embodiments, the additive manufacturing system 100 further includes one or more optical fiber connectors 112 positioned between the laser energy sources 102 and the optics assembly 104. As illustrated, a first plurality of optical fibers 114 may extend between the plurality of laser energy sources 102 and the optical fiber connector 112. In particular, each laser energy source 102 may be coupled to the optical fiber connector 112 via a respective optical fiber 116 of the first plurality of optical fibers 114. Similarly, a second 12486774.1plurality of optical fibers 118 extends between the optical fiber connector 112 and the optics assembly 104. Each optical fiber 116 of the first plurality of optical fibers 114 is coupled to a corresponding optical fiber 120 of the second plurality of optical fibers 118 within the optical fiber connector. In this manner, laser energy from each of the laser energy sources 102 is delivered to the optics assembly 104 such that laser energy 108 can be directed onto the build surface 110 during an additive manufacturing process (i.e., a build process). Of course, other methods of connecting the laser energy sources 100 due to the optics assembly 104 are also contemplated.

[0039] Fig. 2 shows a schematic representation of another embodiment of an additive manufacturing system 200. Similar to the embodiment discussed above in connection with Fig. 1, the additive manufacturing system 200 includes a plurality of laser energy sources 202 coupled to the optics assembly 204 within the machine enclosure 206 via the optical fiber connector 212. The first plurality of optical fibers 214 extends between the laser energy sources 202 and the optical fiber connector 212, and the second plurality of optical fibers 218 extends between the optical fiber connector 212 and optics assembly 204. In particular, each optical fiber 216 of the first plurality of optical fibers is coupled to a laser energy source 202 and corresponding optical fiber 220 of the second plurality of optical fibers 218. In the depicted embodiment, optical fibers 216 are coupled to corresponding optical fibers 220 via fusion splices 222 within the optical fiber connector 212. However, embodiments, in which the optical fibers positioned within the connector are optically coupled using other types of connections and / or single continuous optical fibers are used are also envisioned.

[0040] In the depicted embodiment, the optical fibers 220 of the second plurality of optical fibers 218 are optically coupled to an optics assembly 204 of the system. For example, an alignment fixture 224 is configured to define a desired spatial distribution of the optical fibers used to direct laser energy into the optics assembly. For example, the alignment fixture may comprise a block having a plurality of v-grooves or holes in which the optical fibers may be positioned and coupled to in order to accurately position the optical fibers within the system.

[0041] FIG. 2 also depicts exemplary optics that are optically coupled to and positioned downstream from the second plurality of optical fibers 218. The various optics included in the optics assembly may be configured to direct laser energy 208 from the second 12486774.1plurality of optical fibers 218 on the build surface 210 to form a desired array pattern of laser energy pixels on the build surface. For example, the optics assembly may include beam forming optics such as lenses 226 and 228 (which may be individual lenses, lens arrays, and / or combined macrolenses), mirrors 230, and / or any other appropriate type of optics disposed along the various optical paths between the optical fibers and the build surface 210 which may shape and direct the laser energy within the optics assembly. Once appropriately sized and shaped, the laser energy 208 may be directed onto the build surface 210 either through direct transmission and / or using a light directing element such as the depicted mirror 230.

[0042] FIG. 3 depicts one embodiment of an additive manufacturing system at the beginning of a build process. The additive manufacturing system includes a build plate 302 mounted on a fixed plate 304, which is in turn mounted on one or more vertical supports 306 that attach to a base 308 of the additive manufacturing system. In the depicted embodiment, the one or more vertical supports may correspond to one, two, and / or any other appropriate number of supports configured to support the build plate, and the corresponding build surface, at a desired position and orientation. For example, the supports depicted in the figure may correspond to one or more vertical motion stages configured to control a vertical position and orientation of the build plate. A powder containment shroud 310 may at least partially, and in some embodiments completely, surround a perimeter of the build plate 302 to support a volume of precursor material 302a, such as a volume of powder, disposed on the build plate and contained within the shroud. The shroud may be supported on the base 308 or by any other appropriate portion of the system.

[0043] The additive manufacturing system may include a powder deposition system in the form of a recoater 312 that is mounted on a horizontal motion stage 314 that allows the recoater to be moved back and forth across either a portion, or entire, surface of the build plate 302. As the recoater traversers the build surface of the build plate, it deposits a precursor material 302a, such as a powder, onto the build plate and smooths the surface to provide a layer of precursor material with a predetermined thickness on top of the underlying volume of fused and / or unfused precursor material deposited during prior formation steps. The recoater can include a blade, electrostatic, or other structure to smooth the surface of the deposited powder. 12486774.1

[0044] In some embodiments, the supports 306 of the build plate 302 may be used to index the build surface of the build plate 302 in a vertical downwards direction relative to a local direction of gravity. In such an embodiment, the recoater 312 may be held vertically stationary for dispensing precursor material 302a, such as a precursor powder, onto the exposed build surface of the build plate as the recoater is moved across the build plate each time the build plate is indexed downwards.

[0045] In some embodiments, the additive manufacturing system may also include an optics assembly 318 that is supported vertically above and oriented towards the build plate 302. As detailed above, the optics assembly may be optically coupled to one or more laser energy sources, not depicted, to direct laser energy in the form or one or more laser energy pixels onto the build surface of the build plate 302. To facilitate movement of the laser energy pixels across the build surface, the optics assembly may be configured to move in one, two, or any number of directions in a plane parallel to the build surface of the build plate. To provide this functionality, the optics assembly may be mounted on a gantry 320, or other actuated structure, that allows the optics unit to be scanned in plane parallel to the build surface of the build plate.

[0046] In the above embodiment, the build plate is indexed vertically while the remaining active portions of the system are held vertically stationary. However, embodiments, in which the build plate is held vertically stationary and the shroud 310, recoater 312, and optics assembly 318 are indexed vertically upwards relative to a local direction of gravity during formation of successive layers are also contemplated. In such an embodiment, the recoater horizontal motion stage 314 may be supported by vertical motion stages 316 that are configured to provide vertical movement of the recoater relative to the build plate. Corresponding vertical motion stages may also be provided for the shroud 310, not depicted, to index the shroud vertically upward relative to the build plate in such an embodiment. In some embodiments, the additive manufacturing system may also include an optics assembly 318 that is supported on a vertical motion stage 320 that is in turn mounted on the gantry 320 that allows the optics unit to be scanned in the plane of the build plate 302.

[0047] In the above embodiment, the vertical motion stages, horizontal motion stages, and gantry may correspond to any appropriate type of system that is configured to provide the desired vertical and / or horizontal motion. This may include supporting structures such as: 12486774.1rails; linear bearings, wheels, threaded shafts, and / or any other appropriate structure capable of supporting the various components during the desired movement. Movement of the components may also be provided using any appropriate type of actuator including, but not limited to, electric motors, stepper motors, hydraulic actuators, pneumatic actuators, electric actuators, and / or any other appropriate type of actuator as the disclosure is not so limited.

[0048] In addition to the above, in some embodiments, the depicted additive manufacturing system may include one or more controllers 324 that is operatively coupled to the various actively controlled components of the additive manufacturing system. For example, the one or more controllers may be operatively coupled to the one or more supports 306, recoater 312, optics assembly 318, the various motion stages, and / or any other appropriate component of the system. In some embodiments, the one or more controllers may include one or more processors and associated non-transitory computer readable memory. The non-transitory computer readable memory may include processor executable instructions that when executed by the one or more processors cause the additive manufacturing system to perform any of the methods disclosed herein.

[0049] FIG. 5 is a block diagram of an exemplary build plan generation system 500 including a process controller 502, according to some embodiments. The process controller 502, and / or more generally, the build plan generation system 500, can control a geometry of melt pools at end portions (e.g., end portions 602, 604 of FIG. 6, end portions 810, 820, 830, 840 of FIG. 8, or end portions 910, 940 of FIG. 9) of scanning trajectories followed by one or more laser energy sources for multiple layers during the bulk laser scanning phase.

[0050] In some embodiments, the additive manufacturing system 504 of the illustrated example can be implemented by additive manufacturing system 100 of FIG.1, additive manufacturing system 200 of FIG. 2, and / or the additive manufacturing system 300 of FIG. 3. For example, the additive manufacturing system 504 can carry out and / or perform additive manufacturing techniques, such as laser bed powder fusion (LBPF). The additive manufacturing system 504 of the illustrated example includes an optics assembly 508, a part 510, and a build plate 512. Other additive manufacturing system components, such as those depicted in the examples of FIGS. 1 and / or 3, are contemplated but are not shown for clarity. In some embodiments, the optics assembly 508 can be implemented by the optics assembly 104 of FIG. 1 and / or the optics assembly 204 of FIG. 2. 12486774.1

[0051] In some embodiments, the additive manufacturing system 504 can be configured to construct and / or fabricate the part 510, or layer(s) thereof, using parameters, such as LBPF parameters. For example, the process controller 502 can generate instructions 514 representative of LBPF parameters and provide the instructions 514 to the additive manufacturing system 504 to cause the additive manufacturing system 504 to fabricate the part 510 according to the LBPF parameters.

[0052] In some embodiments, the process controller 502 can obtain and / or receive a 3D part file 516 from a server 518 via a network 520. The 3D part file 516 can be a 3D model of the part 510, or portion(s) thereof, such as one or more layers to be fabricated to form the part 510. In some embodiments, the 3D part file 516 is a computer aided design (CAD) model, such as a solid model, a surface model, or a wireframe model. The 3D part file 516 can be a file in any format. Non-limiting examples of file formats include STEP, IGES, 3D PDF, JT, STL, ACIS, PARASOLID, and QIF.

[0053] The server 518 of the illustrated example can be a computer and / or electronic server that can store data, such as the 3D part file 516, for access via the network 520. For example, the server 518 can be a blade server or a rack-mounted server. Alternatively, the server 518 may be implemented by a cellular network device (e.g., an Internet-enabled smartphone, a telecommunications server), a desktop computer, a laptop computer, a workstation, or any other type of computing and / or electronic device.

[0054] The network 520 of the illustrated example can be implemented by any wired and / or wireless network(s) such as one or more cloud networks (e.g., one or more private cloud networks, one or more public cloud networks), one or more cellular networks (e.g., 4G LTE cellular networks, 5G cellular networks, 6G cellular networks, etc.), one or more data buses, one or more edge networks, one or more local area networks (LANs), one or more optical fiber networks, one or more private networks, one or more public networks, one or more wireless local area networks (WLANs), etc., and / or any combination(s) thereof. For example, the network 520 can be the Internet, but any other type of private and / or public network is contemplated.

[0055] The process controller 502 of the illustrated example includes and / or implements a data interface module 530, a layer generation module 532, and a configuration determination module 534. Component(s) of the process controller 502 can be in 12486774.1communication with one(s) of each other via a bus 550. In some embodiments, the bus 550 can be any type of computing and / or electrical bus, such as an Inter-Integrated Circuit (I2C) bus, a Peripheral Component Interconnect (PCI) bus, a Peripheral Component Interconnect Express (PCIe) bus, a Serial Peripheral Interface (SPI) bus, and / or the like.

[0056] In some embodiments, the process controller 502 includes the data interface module 530 to transmit data. For example, the data interface module 530 can transmit data to a system, such as by transmitting the instructions 514 to the additive manufacturing system 504. In some embodiments, the data interface module 530 can receive data. For example, the data interface module 530 can receive data, such as, part geometry, via a network, such as by receiving the 3D part file 516 from the server 518 via the network 520.

[0057] In some embodiments, the process controller 502 includes the layer generation module 532 that processes the part geometry into a plurality of slices. The layer generation module 532 may slice or divide a 3D model of a part into a series of two dimensional (2D) layers, each representing a specific height within the part. In some embodiments, the sliced geometry can be implemented by a common layer interface (CLI) file (e.g., a .CLI file). For example, the CLI file can store data representing the geometrical information of the intersection of a 3D model with a plane (which may also be referred to as a slice). In some embodiments, the volume between two parallel slices may be referred to as a layer.

[0058] In some embodiments, the layer generation module 532 may specify, for each layer, the paths to be followed by the one or more laser energy sources to selectively melt the precursor material. For example, FIG. 6 shows an example scanning trajectory 600, or a portion thereof, followed by the one or more laser energy sources for a layer of precursor material. The scanning trajectory of FIG. 6 includes multiple scans 610 following a back-and- forth pattern along a particular scanning orientation (e.g., a first horizontal scanning orientation 620). In some embodiments, the scanning orientation may be changed between layers. For example, as shown in FIG. 7, the scanning trajectory 700, or portion thereof, followed by the one or more laser energy sources for a layer may include one or more first scans 702 in a first scanning orientation 750 (e.g., vertical orientation), and the scanning trajectory 720, or portion thereof, followed by the one or more laser energy sources for another layer may include one or more second scans 704 in a second scanning orientation 760 (e.g., horizontal orientation). In some embodiments, the second scanning orientation may be 12486774.1perpendicular to the first scanning orientation. In some embodiments, the first scanning orientation may be a first angular orientation and second scanning orientation may be a different angular orientation (e.g., perpendicular or at different angles). The one or more laser energy sources may scan according to the one or more first scans 702 for a first layer, followed by one or more second scans 704 for a second layer, followed by one or more first scans 702 for a third layer, followed by one or more second scans 704 for a fourth layer, and so on until the final 3D part 730 is fabricated.

[0059] In some embodiments, the process controller 502 includes the configuration determination module 534 to determine a configuration of the additive manufacturing system 504, or portion(s) thereof such as the laser energy sources and / or the optics assembly 508, for fabrication of the part 510, or layer(s) thereof. For example, the configuration determination module 534 can determine and / or generate parameters, such as LBPF parameters, to configure the additive manufacturing system 504. In some embodiments, the configuration determination module 534 can generate a file, such as a print file, based on the parameters. The configuration determination module 534 can generate the instructions 514 to be provided to the additive manufacturing system 504.

[0060] In some embodiments, the configuration determination module 534 can determine one or more LBPF parameters for one or more laser energy sources, such as, but not limited to, at least one of a laser power, a scanning speed, a spot size, a hatch spacing, or one or more other parameters of the one or more laser energy sources. Any other type of parameter is contemplated such as information including locations of a plurality of laser energy pixels on a build surface (e.g., the metal powder bed) during the build process, trajectories of the laser energy pixels across the build surface, a list of operating parameters for the laser energy pixels, expected intensity values of laser energy pixels projected onto the build surface, expected radiation emissions and / or reflections of welds and / or melt pools (e.g., an expected weld signature), and / or any other appropriate parameter.

[0061] In some embodiments, the configuration determination module 534 can determine one or more LBPF parameters for the one or more laser energy sources on a layer- by-layer basis. The inventors have recognized that by controlling one or more LPBF parameters (e.g., laser power, spot size, hatch spacing, and / or other parameters) of the one or more laser energy sources at end portions of the first and second scans (e.g., on a layer-by- 12486774.1layer basis), the geometry of the melt pools at those end portions can be controlled and / or adjusted resulting in reduced lack of fusion defects. Such control eliminates the need for a contouring phase in the LPBF process. For example, the laser power level applied at each of the end portions may be controlled to control the melt pool shape and / or size at the end portion.

[0062] In some embodiments, an end portion may refer to any location along a scanning trajectory for a layer where the laser energy source(s) is turned on or off to form an edge of the part within the layer. In some embodiments, an end portion may refer to any location along a scanning trajectory for a layer that corresponds to a laser on and / or laser off event indicating an edge of the part within the layer. A laser on event may refer to the activation or turning on of the laser energy source(s) and a laser off event may refer to the deactivation or turning off of the laser energy source(s). For example, FIG. 6 depicts end portions 602, 604 of one of the scans in the scanning trajectory for a layer, where end portion 602 may correspond to a laser on event and end portion 604 may correspond to a laser off event. In some embodiments, multiple end portions, e.g., end portions 810, 820, 830, 840 may exist along a scan of a scanning trajectory, as shown in FIG. 8. It will be appreciated that while FIGs. 6 and 8 depict two and four end portions along a scan, any number of end portions may exist along a scan (and hence the scanning trajectory for each layer) depending on a shape of the 3D part to be printed.

[0063] In some embodiments, the LPBF parameters may be optimized and / or chosen using one or more machine learning models that is trained to predict optimal parameters for controlling the melt pool geometry at the end portions based on training. In some embodiments, the configuration determination module 534 may invoke a machine learning model to generate and / or predict a configuration of an additive manufacturing system based on the layer(s) associated with a part. The layer(s) may be provided as input to the machine learning model to generate output(s), which can include one or more LPBF parameters that optimize and / or otherwise improve fabrication of the layer(s).

[0064] Non-limiting examples of a machine learning model include a deep learning model, a clustering model, a decision tree, a support vector machine (SVM), a Bayesian network, a hidden Markov model, and / or any combination(s) thereof. Non-limiting examples of a deep learning model include a convolutional neural network (CNN), a graph neural 12486774.1network (GNN), a recurrent neural network (RNN), a multi-layer perceptron, an autoencoder, a generative adversarial network (GAN), a CTC-fitted neural network model, and / or any combination(s) thereof.

[0065] The machine learning model(s) may be trained or retrained using training data. For example, the machine leaning model(s) may be trained by applying a supervised learning training algorithm using labeled training data. As an example, a deep learning model (e.g., a neural network) may be trained by using stochastic gradient descent. As another example, an SVM may be trained to identify decision boundaries of the SVM by optimizing a cost function. Inputs to the machine learning model(s) may be generated using the training data, the training data may be labeled using data values from additive manufacturing experts; and a supervised training algorithm may be applied to the generated inputs and corresponding labels. Additionally or alternatively, the machine leaning model(s) may be trained by applying an unsupervised learning algorithm and / or a semi-supervised learning algorithm to the training data.

[0066] In some embodiments, the training data can include data representative of relationships between at least one of powder bed material, geometry partitionings (e.g., slices, layers) of 3D parts, and / or configurations (e.g., LPBF parameters) of the additive manufacturing system. In some embodiments, the relationships were established in connection with previously fabricated parts. For example, the relationships may have been established from previous iterative experimentation for process development of a part. The machine learning model may be retrained using new and / or revised portion(s) of the training data on a periodic or aperiodic basis. For example, a previously trained neural network may be updated by updating values of one or more parameters of the neural network using new training data. In some embodiments, the neural network may be updated by training a new neural network using a combination of previously obtained training data and new training data.

[0067] In some embodiments, feedback obtained based on review of the output(s) of the machine learning model may be used to adjust the machine learning model. For example, a user associated with an additive manufacturing system (e.g., an engineer, a technician, quality control personnel, etc.) can evaluate the configuration and make adjustment(s). In some embodiments, the user can provide the adjustment(s) to machine learning model via a 12486774.1graphical user interface (GUI). For example, the adjustment(s) and associated data can be used to retrain the machine learning model.

[0068] In some embodiments, the configuration determination module 534 may determine one or more LPBF parameters to be used for controlling the melt pool geometry during the bulk laser scanning phase. For example, the configuration determination module 534 may determine a power level of the one or more laser energy sources to be applied at or around the end portions of the first and second scans. In some embodiments, the configuration determination module 534 may determine a first power level to be applied at or around the end portions of the first and second scans and a second power level to be applied at regions between the end portions of the first and second scans. The second power level applied at the regions between the end portions may be lower than the first power level applied at or around the end portions. For example, FIG. 6 illustrates end portions 602, 604 of one of the scans 610 in a first scanning orientation. The configuration determination module 534 may determine the first power level to be applied at or around these end portions 602, 604 and the second power level to be applied at regions between these end portions. It will be appreciated that similar determinations of power levels may be made for end portions of each of the first scans 702, the end portions of each of the second scans 704, and regions between the end portions of each of the first and second scans without departing from the scope of this disclosure.

[0069] The inventors recognized that determining an appropriate power level to be applied at or around each or any of the end portions of the first / second scans is important to ensure that melt pools at the end portions have a particular geometry (e.g., shape and / or size) that enables overlap at the edges, thereby reducing lack of fusion defects. The appropriate power level to be applied at or around the end portions may be determined by performing various simulations to understand the relationship between laser on / off signals at different power levels and resulting end portion melting behaviors. Simulations providing insights into the time delays between the laser on / off signals and melt pool responses to end portion melting behaviors were performed. Various parameters were measured, such as, a distance between the laser-on spot and where the melt pool depth reaches maximum condition along with the associated melt pool response time, a distance between the laser-on spot and where the melt pool width reaches maximum condition along with the associated melt pool response 12486774.1time, a distance between the laser-off spot and where the melt pool depth starts to reduce / close along with the associated melt pool response time, and the distance between the laser-off spot and where the melt pool width starts to shrink along with the associated melt pool response time. In some embodiments, the machine learning model(s) may be trained using these insights, parameters, etc. to predict optimal parameters for configuring an additive manufacturing system, and in particular, to control the melt pool geometry at the end portions during the bulk laser scanning phase.

[0070] Based on the simulations, a determination was made that a first power level to be applied at or around the end portions of the first and second scans may be 220W, a range between 180W–260W, or any other suitable value / range and a second power level to be applied at the regions between the end portions of the first and second scans may be 200W, a range between 160W-240W, or any other suitable value / range.

[0071] In some embodiments, one or more of the following determinations regarding the manner in which power level adjustments are to be applied to the various end portions during the first and second scans may be made based on the simulations: (i) a point (e.g. at or around end portion 910 shown in FIG. 9) at which the laser power level is to be increased to the first power level, (ii) a first distance 915 following end portion 910 for which the first power level is to be maintained; (iii) a point 920 (e.g., at or around the end of the first distance) at which the laser power level is to be decreased to the second power level; (iv) a second distance 925 for which the second power level is to be maintained, (v) a point 930 (e.g., at or around the end of the second distance before the end portion 940) at which the laser power level is to be increased to the first power level; and (vi) a third distance 935 for which the first power level is to be maintained. In some embodiments, the one or more LPBF parameters to be used for controlling the melt pool geometry during the bulk laser scanning phase may include parameters for one or more laser energy sources, for example, laser power levels, such as first and second power levels; distances and / or points at which the power levels are to be increased, decreased, or maintained; hatch spacing between scans, and / or other parameters. It will be appreciated that while these parameters were determined for a particular part geometry and additive manufacturing system, different systems / parts may result in the use of different parameters for laser energy sources without departing from the scope of this disclosure. 12486774.1

[0072] The inventors recognized that a 3D part printed using build plans including these additional LPBF parameters for controlling the melt pool geometry resulted in finished 3D parts with surface roughness quality, comparable to or better than existing contouring techniques.

[0073] In some embodiments, the configuration determination module 534 may generate a build plan including the trajectories and / or LPBF parameters. The generated build plan may be transmitted to the additive manufacturing system 504 as instructions 514. For example, the data interface module 530 may transmit a file which includes instructions 514 for the additive manufacturing system 504 to execute the build plan. The additive manufacturing system 504 performs the layer-by-layer fabrication, melting or depositing the material as per the build plan, resulting in the creation of the 3D printed part.

[0074] While an example implementation of the process controller 502, and / or, more generally, the build plan generation system 500, is depicted in FIG. 5, other implementations are contemplated. For example, one or more blocks, components, functions, etc., of the process controller 502, and / or, more generally, the build plan generation system 500 may be combined or divided in any other way. The process controller 502, and / or, more generally, the build plan generation system 500 of the illustrated example may be implemented by hardware alone, or by a combination of hardware, software, and / or firmware. For example, the process controller 502, and / or, more generally, the build plan generation system 500 may be implemented by one or more analog or digital circuits (e.g., comparators, operational amplifiers, etc.), one or more hardware-implemented state machines, one or more programmable processors (e.g., central processing units (CPUs), digital signal processors (DSPs), field programmable gate arrays (FPGAs), etc.), one or more network interfaces (e.g., network interface circuitry, network interface cards (NICs), smart NICs, etc.), one or more ASICs, one or more memories (e.g., non-volatile memory, volatile memory, etc.), one or more mass storage disks or devices (e.g., hard-disk drives (HDDs), solid-state disk (SSD) drives, etc.), etc., and / or any combination(s) thereof.

[0075] FIG. 10 depict an example flowchart representative of machine-readable instructions that may be executed by processor circuitry to implement one or more controllers, such as the process controller 502 of FIG. 5. Additionally, or alternatively acts of the flowchart of FIG. 10 may be representative of state(s) of one or more hardware- 12486774.1implemented state machines, algorithm(s) that may be implemented by hardware alone such as an ASIC, etc., and / or any combination(s) thereof.

[0076] FIG. 10 is an example flowchart of a process 1000 of generating a build plan including one or more parameters to be used for controlling melt pool geometry during the bulk laser scanning phase. Process 1000 may be executed by the process controller 502 of FIG. 5. Process 1000 begins at act 1002, where the 3D model of a part to fabricate with additive manufacturing is obtained by the process controller 502. For example, the data interface module 530 can obtain the 3D part file 516 from the server 518 via the network 520. In some embodiments, the 3D part file 516 can be a digital representation of the part 510 to be fabricated by the additive manufacturing system 504 of FIG. 5.

[0077] At act 1004, the process controller 502 slices the 3D model into layers. For example, the layer generation module 532 may slice the 3D part file into a plurality of layers.

[0078] At act 1006, the process controller 502 determines one or more parameters for one or more laser energy sources to be used to control melt pool geometry. For example, the configuration determination module 534 may determine a power level of the one or more laser energy sources to be applied at or around end portions associated with each scan of the first scans and each scan of the second scans. The configuration determination module 534 may also determine a power level of the one or more laser energy sources to be applied at regions between the end portions.

[0079] At act 1008, the process controller 502 may generate a build plan and communicate instructions to execute the build plan to the additive manufacturing system 504. For example, the configuration determination module 534 can generate and / or output a print file for fabrication of the part 510. In some embodiments, the print file can include the instructions 514 of FIG. 5 that, when executed by the additive manufacturing system 504, fabricates the part 510, or layer(s) thereof, in accordance with the LBPF parameters.

[0080] In some embodiments, the controller 324, and / or, more generally, the additive manufacturing system 300 of FIG. 3 or system 504 of FIG. 5 may execute the instructions 514 to control the geometry of the melt pools at end portions of scanning trajectories followed by the one or more laser energy sources. The instructions may control one or more parameters of the one or more laser energy sources at end portions of one or more first scans in the first scanning orientation and at end portions of the one or more second scans in the 12486774.1second scanning orientation. In some embodiments, controlling the one or more parameters of the laser energy sources may include controlling the power levels of the laser energy sources as described herein. In some embodiments, the power levels of the one or more laser energy sources may be controlled while maintaining a substantially constant laser scanning speed.

[0081] The above method may be implemented by one or more controllers including at least one processor operatively coupled to the various controllable portions of an additive manufacturing system as disclosed herein. The method may be embodied as computer readable instructions stored on non-transitory computer readable memory associated with the at least one processor such that when executed by the at least one processor the additive manufacturing system may perform any of the actions related to the methods disclosed herein. Additionally, it should be understood that the disclosed order of the steps is exemplary and that the disclosed steps may be performed in a different order, simultaneously, and / or may include one or more additional intermediate steps not shown as the disclosure is not so limited.

[0082] The above-described embodiments of the technology described herein can be implemented in any of numerous ways. For example, the embodiments may be implemented using hardware, software or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computing device or distributed among multiple computing devices. Such processors may be implemented as integrated circuits, with one or more processors in an integrated circuit component, including commercially available integrated circuit components known in the art by names such as CPU chips, GPU chips, microprocessor, microcontroller, or co-processor. Alternatively, a processor may be implemented in custom circuitry, such as an ASIC, or semicustom circuitry resulting from configuring a programmable logic device. As yet a further alternative, a processor may be a portion of a larger circuit or semiconductor device, whether commercially available, semi-custom or custom. As a specific example, some commercially available microprocessors have multiple cores such that one or a subset of those cores may constitute a processor. Though, a processor may be implemented using circuitry in any suitable format. 12486774.1

[0083] Further, it should be appreciated that a computing device including one or more processors may be embodied in any of a number of forms, such as a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer. Additionally, a computing device may be embedded in a device not generally regarded as a computing device but with suitable processing capabilities, including a Personal Digital Assistant (PDA), a smart phone, tablet, or any other suitable portable or fixed electronic device.

[0084] Also, a computing device may have one or more input and output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include display screens for visual presentation of output and speakers or other sound generating devices for audible presentation of output. Examples of input devices that can be used for a user interface include keyboards, individual buttons, and pointing devices, such as mice, touch pads, and digitizing tablets. As another example, a computing device may receive input information through speech recognition or in other audible format.

[0085] Such computing devices may be interconnected by one or more networks in any suitable form, including as a local area network or a wide area network, such as an enterprise network or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol and may include wireless networks, wired networks or fiber optic networks.

[0086] Also, the various methods or processes outlined herein may be coded as software that is executable on one or more processors that employ any one of a variety of operating systems or platforms. Additionally, such software may be written using any of a number of suitable programming languages and / or programming or scripting tools, and also may be compiled as executable machine language code or intermediate code that is executed on a framework or virtual machine.

[0087] In this respect, the embodiments described herein may be embodied as a computer readable storage medium (or multiple computer readable media) (e.g., a computer memory, one or more floppy discs, compact discs (CD), optical discs, digital video disks (DVD), magnetic tapes, flash memories, RAM, ROM, EEPROM, circuit configurations in Field Programmable Gate Arrays or other semiconductor devices, or other tangible computer storage medium) encoded with one or more programs that, when executed on one or more 12486774.1computers or other processors, perform methods that implement the various embodiments discussed above. As is apparent from the foregoing examples, a computer readable storage medium may retain information for a sufficient time to provide computer-executable instructions in a non-transitory form. Such a computer readable storage medium or media can be transportable, such that the program or programs stored thereon can be loaded onto one or more different computing devices or other processors to implement various aspects of the present disclosure as discussed above. As used herein, the term "computer-readable storage medium" encompasses only a non-transitory computer-readable medium that can be considered to be a manufacture (i.e., article of manufacture) or a machine. Alternatively or additionally, the disclosure may be embodied as a computer readable medium other than a computer-readable storage medium, such as a propagating signal.

[0088] The terms “program” or “software” are used herein in a generic sense to refer to any type of computer code or set of computer-executable instructions that can be employed to program a computing device or other processor to implement various aspects of the present disclosure as discussed above. Additionally, it should be appreciated that according to one aspect of this embodiment, one or more computer programs that when executed perform methods of the present disclosure need not reside on a single computing device or processor, but may be distributed in a modular fashion amongst a number of different computers or processors to implement various aspects of the present disclosure .

[0089] Computer-executable instructions may be in many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments.

[0090] The embodiments described herein may be embodied as a method, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.

[0091] Further, some actions are described as taken by a “user.” It should be appreciated that a “user” need not be a single individual, and that in some embodiments, 12486774.1actions attributable to a “user” may be performed by a team of individuals and / or an individual in combination with computer-assisted tools or other mechanisms.

[0092] FIG. 11 is an example implementation of an electronic platform 1100 structured to execute the machine-readable instructions of FIG. 10 to implement a process controller, such as the process controller 502 of FIG. 5. It should be appreciated that FIG. 11 is intended neither to be a description of necessary components for an electronic and / or computing device to operate as a process controller or process control circuitry, in accordance with the techniques described herein, nor a comprehensive depiction. The electronic platform 1100 of this example may be an additive manufacturing computer, an electronic device, such as a cellular network device, a desktop computer, a laptop computer, a server (e.g., a computer server, a blade server, a rack-mounted server, etc.), a workstation, or any other type of computing and / or electronic device.

[0093] The electronic platform 1100 of the illustrated example includes processor circuitry 1102, which may be implemented by one or more programmable processors, one or more hardware-implemented state machines, one or more ASICs, etc., and / or any combination(s) thereof. For example, the one or more programmable processors may include one or more CPUs, one or more DSPs, one or more FPGAs, etc., and / or any combination(s) thereof. The processor circuitry 1102 includes processor memory 1104, which may be volatile memory, such as random-access memory (RAM) of any type. The processor circuitry 1102 of this example implements the layer generation module 532 and configuration determination module 534 of FIG. 5.

[0094] The processor circuitry 1102 may execute machine-readable instructions 1106 (identified by INSTRUCTIONS), which are stored in the processor memory 1104, to implement the process controller 502 of FIG. 2. The machine-readable instructions 1106 may include data representative of computer-executable and / or machine-executable instructions implementing techniques that operate according to the techniques described herein. For example, the machine-readable instructions 1106 may include data (e.g., code, embedded software (e.g., firmware), software, etc.) representative of the flowchart of FIG. 10, or portion(s) thereof.

[0095] The electronic platform 1100 includes memory 1108, which may include the instructions 1106. The memory 1108 of this example may be controlled by a memory 12486774.1controller 1110. For example, the memory controller 1110 may control reads, writes, and / or, more generally, access(es) to the memory 1108 by other component(s) of the electronic platform 1100. The memory 1108 of this example may be implemented by volatile memory, non-volatile memory, etc., and / or any combination(s) thereof. For example, the volatile memory may include static random-access memory (SRAM), dynamic random-access memory (DRAM), cache memory (e.g., Level 1 (L1) cache memory, Level 2 (L2) cache memory, Level 3 (L3) cache memory, etc.), etc., and / or any combination(s) thereof. In some examples, the non-volatile memory may include Flash memory, electrically erasable programmable read-only memory (EEPROM), magnetoresistive random-access memory (MRAM), ferroelectric random-access memory (FeRAM, F-RAM, or FRAM), etc., and / or any combination(s) thereof.

[0096] The electronic platform 1100 includes input device(s) 1112 to enable data and / or commands to be entered into the processor circuitry 1102. For example, the input device(s) 1112 may include an audio sensor, a camera (e.g., a still camera, a video camera, etc.), a keyboard, a microphone, a mouse, a touchscreen, a voice recognition system, etc., and / or any combination(s) thereof.

[0097] The electronic platform 1100 includes output device(s) 1114 to convey, display, and / or present information to a user (e.g., a human user, a machine user, etc.). For example, the output device(s) 1114 may include one or more display devices, speakers, etc. The one or more display devices may include an augmented reality (AR) and / or virtual reality (VR) display, a liquid crystal display (LCD), a light-emitting diode (LED) display, an organic light-emitting diode (OLED) display, a quantum dot (QLED) display, a thin-film transistor (TFT) LCD, a touchscreen, etc., and / or any combination(s) thereof. The output device(s) 1014 can be used, among other things, to generate, launch, and / or present a user interface. For example, the user interface may be generated and / or implemented by the output device(s) 1114 for visual presentation of output and speakers or other sound generating devices for audible presentation of output.

[0098] The electronic platform 1100 includes accelerators 1116, which are hardware devices to which the processor circuitry 1102 may offload compute tasks to accelerate their processing. For example, the accelerators 1116 may include artificial intelligence / machine- learning (AI / ML) processors, ASICs, FPGAs, graphics processing units (GPUs), neural 12486774.1network (NN) processors, systems-on-chip (SoCs), vision processing units (VPUs), etc., and / or any combination(s) thereof. In some examples, the layer generation module 532 and / or configuration determination module 534 may be implemented by one(s) of the accelerators 1116 instead of the processor circuitry 1102. In some examples, the layer generation module 532 and / or configuration determination module 534 may be executed concurrently (e.g., in parallel, substantially in parallel, etc.) by the processor circuitry 1102 and the accelerators 1116.

[0099] The electronic platform 1100 includes storage 1118 to record and / or control access to data, such as the machine-readable instructions 1106. The storage 1118 may be implemented by one or more mass storage disks or devices, such as HDDs, SSDs, etc., and / or any combination(s) thereof.

[0100] The electronic platform 1100 includes interface(s) 1120 to effectuate exchange of data with external devices (e.g., computing and / or electronic devices of any kind) via a network 1122. In this example, the interface(s) 1120 implements the data interface module 530 of FIG. 5. The interface(s) 1120 of the illustrated example may be implemented by an interface device, such as network interface circuitry (e.g., a NIC, a smart NIC, etc.), a gateway, a router, a switch, etc., and / or any combination(s) thereof. The interface(s) 1120 may implement any type of communication interface, such as BLUETOOTH®, a cellular telephone system (e.g., a 4G LTE interface, a 5G interface, a 6G interface, etc.), an Ethernet interface, a near-field communication (NFC) interface, an optical disc interface (e.g., a Blu- ray disc drive, a Compact Disk (CD) drive, a Digital Versatile Disk (DVD) drive, etc.), an optical fiber interface, a satellite interface (e.g., a beyond-line-of-site (BLOS) satellite interface, a line-of-site (LOS) satellite interface, etc.), a Universal Serial Bus (USB) interface (e.g., USB Type-A, USB Type-B, USB TYPE-C™ or USB-C™, etc.), etc., and / or any combination(s) thereof.

[0101] The electronic platform 1100 includes a power supply 1124 to store energy and provide power to components of the electronic platform 1100. The power supply 1124 may be implemented by a power converter, such as an alternating current-to-direct-current (AC / DC) power converter, a direct current-to-direct current (DC / DC) power converter, etc., and / or any combination(s) thereof. For example, the power supply 1124 may be powered by an external power source, such as an alternating current (AC) power source (e.g., an electrical 12486774.1grid), a direct current (DC) power source (e.g., a battery, a battery backup system, etc.), etc., and the power supply 1124 may convert the AC input or the DC input into a suitable voltage for use by the electronic platform 1100. In some examples, the power supply 1124 may be a limited duration power source, such as a battery (e.g., a rechargeable battery such as a lithium-ion battery).

[0102] Component(s) of the electronic platform 1100 may be in communication with one(s) of each other via a bus 1126. For example, the bus 1126 may be any type of computing and / or electrical bus, such as an I2C bus, a PCI bus, a PCIe bus, a SPI bus, and / or the like. In some embodiments, the bus 1126 of FIG. 11 can implement the bus 550 of FIG. 5.

[0103] The network 1122 may be implemented by any wired and / or wireless network(s) such as one or more cellular networks (e.g., 4G LTE cellular networks, 5G cellular networks, 6G cellular networks, etc.), one or more data buses, one or more local area networks (LANs), one or more optical fiber networks, one or more private networks, one or more public networks, one or more wireless local area networks (WLANs), etc., and / or any combination(s) thereof. For example, the network 1122 may be the Internet, but any other type of private and / or public network is contemplated. In some embodiments, the network 1022 can implement the network 520 of FIG. 5.

[0104] The network 1122 of the illustrated example facilitates communication between the interface(s) 1120 and a central facility 1128. The central facility 1128 in this example may be an entity associated with one or more servers, such as one or more physical hardware servers and / or virtualizations of the one or more physical hardware servers. For example, the central facility 1128 may be implemented by a public cloud provider, a private cloud provider, etc., and / or any combination(s) thereof. In this example, the central facility 1128 may compile, generate, update, etc., the machine-readable instructions 1106 and store the machine-readable instructions 1106 for access (e.g., download) via the network 1122. For example, the electronic platform 1100 may transmit a request, via the interface(s) 1120, to the central facility 1128 for the machine-readable instructions 1106 and receive the machine- readable instructions 1106 from the central facility 1128 via the network 1122 in response to the request. In some embodiments, the central facility 1128 can implement the server 518 of FIG. 5. 12486774.1

[0105] Additionally or alternatively, the interface(s) 1120 may receive the machine- readable instructions 1106 via non-transitory machine-readable storage media, such as an optical disc 1130 (e.g., a Blu-ray disc, a CD, a DVD, etc.) or any other type of removable non-transitory machine-readable storage media such as a USB drive 1132. For example, the optical disc 1130 and / or the USB drive 1132 may store the machine-readable instructions 1106 thereon and provide the machine-readable instructions 1106 to the electronic platform 1100 via the interface(s) 1120.

[0106] Various aspects of the technology described herein may be used alone, in combination, or in a variety of arrangements not specifically described in the embodiments described in the foregoing and is therefore not limited in its application to the details and arrangement of modules set forth in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments.

[0107] Also, the technology described herein may be embodied as a method, of which examples are provided herein. The acts performed as part of any of the methods may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.

[0108] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0109] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0110] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and / or B,” when 12486774.1used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0111] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0112] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively.

[0113] The terms “approximately” and “about” may be used to mean within ±20% of a target value in some embodiments, within ±10% of a target value in some embodiments, within ±5% of a target value in some embodiments, within ±2% of a target value in some embodiments. The terms “approximately” and “about” may include the target value.

[0114] Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, 12486774.1but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

[0115] While the present teachings have been described in conjunction with various embodiments and examples, it is not intended that the present teachings be limited to such embodiments or examples. On the contrary, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art. Accordingly, the foregoing description and drawings are by way of example only. 12486774.1

Claims

CLAIMS 1. An additive manufacturing system comprising: a build surface; one or more laser energy sources; an optics assembly movable relative to the build surface and configured to direct laser energy from the one or more laser energy sources toward the build surface to melt at least a portion of a layer of material disposed on the build surface; and a controller operatively coupled to the optics assembly and configured to: control a geometry of melt pools at end portions of scanning trajectories followed by the one or more laser energy sources, a first scanning trajectory of the scanning trajectories including one or more first scans in a first scanning orientation and a second scanning trajectory of the scanning trajectories including one or more second scans in a second scanning orientation, wherein to control the geometry of melt pools the controller is further configured to: control one or more parameters of the one or more laser energy sources at end portions of the one or more first scans in the first scanning orientation and at end portions of the one or more second scans in the second scanning orientation.

2. The additive manufacturing system of claim 1, wherein the controller is further configured to control a shape and / or size of the melt pool at the end portions of the scanning trajectories.

3. The additive manufacturing system of claim 1, wherein the controller is further configured to: control a power level of the one or more laser energy sources at the end portions of the one or more first scans and the end portions of the one or more second scans. 12486774.

14. The additive manufacturing system of claim 3, wherein the controller is further configured to control the power level of the one or more laser energy sources while maintaining a substantially constant laser scanning speed.

5. The additive manufacturing system of claim 3, wherein controlling the power level of the one or more laser energy sources comprises: increasing the power level of the one or more laser energy sources to a first power level at the end portions of the one or more first scans.

6. The additive manufacturing system of claim 5, wherein controlling the power level of the one or more laser energy sources further comprises: for each first scan of the one or more first scans: maintaining the power level of the one or more laser energy sources at the first power level for a first predetermined distance following a first end portion of the first scan; decreasing, at an end of the first predetermined distance, the power level of the one or more laser energy sources from the first power level to a second power level lower than the first power level; maintaining the power level of the one or more laser energy sources at the second power level for a second predetermined distance; and increasing the power level of the one or more laser energy sources to the first power level at an end of the second predetermined distance.

7. The additive manufacturing system of claim 6, controlling the power level of the one or more laser energy sources further comprises: increasing the power level of the one or more laser energy sources to the first power level at the end portions of the one or more second scans.

8. The additive manufacturing system of claim 7, wherein controlling the power level of the one or more laser energy sources further comprises: for each second scan of the one or more second scans: 12486774.1maintaining the power level of the one or more laser energy sources at the first power level for a third predetermined distance following a first end portion of the second scan; decreasing, at an end of the third predetermined distance, the power level of the one or more laser energy sources from the first power level to the second power level lower than the first power level; maintaining the power level of the one or more laser energy sources at the second power level for a fourth predetermined distance; and increasing the power level of the one or more laser energy sources to the first power level at an end of the fourth predetermined distance.

9. The additive manufacturing system of claim 1, wherein the second scanning orientation is perpendicular to the first scanning orientation.

10. A method for additive manufacturing comprising: directing laser energy from one or more laser energy sources through an optics assembly and toward a build surface; melting at least a portion of a layer of material on the build surface due to exposure of the portion to the laser energy; and controlling a geometry of melt pools at end portions of scanning trajectories followed by the one or more laser energy sources, a first scanning trajectory of the scanning trajectories including one or more first scans in a first scanning orientation and a second scanning trajectory of the scanning trajectories including one or more second scans in a second scanning orientation, wherein controlling the geometry of melt pools comprises: controlling one or more parameters of the one or more laser energy sources at end portions of the one or more first scans in the first scanning orientation and at end portions of the one or more second scans in the second scanning orientation.

11. The method of claim 10, wherein controlling the geometry of the melt pools comprises controlling a shape and / or size of the melt pool at the end portions of the scanning trajectories. 12486774.

112. The method of claim 10, wherein controlling the one or more parameters of the one or more laser energy sources comprises: controlling a power level of the one or more laser energy sources at the end portions of the one or more first scans and the end portions of the one or more second scans.

13. The method of claim 12, wherein controlling the power level of the one or more laser energy sources comprises controlling the power level of the one or more laser energy sources while maintaining a substantially constant laser scanning speed.

14. The method of claim 12, wherein controlling the power level of the one or more laser energy sources comprises: increasing the power level of the one or more laser energy sources to a first power level at the end portions of the one or more first scans.

15. The method of claim 14, wherein controlling the power level of the one or more laser energy sources further comprises: for each first scan of the one or more first scans: maintaining the power level of the one or more laser energy sources at the first power level for a first predetermined distance following a first end portion of the first scan; decreasing, at an end of the first predetermined distance, the power level of the one or more laser energy sources from the first power level to a second power level lower than the first power level; maintaining the power level of the one or more laser energy sources at the second power level for a second predetermined distance; and increasing the power level of the one or more laser energy sources to the first power level at an end of the second predetermined distance.

16. The method of claim 15, wherein controlling the power level of the one or more laser energy sources further comprises: 12486774.1increasing the power level of the one or more laser energy sources to the first power level at the end portions of the one or more second scans.

17. The method of claim 16, wherein controlling the power level of the one or more laser energy sources further comprises: for each second scan of the one or more second scans: maintaining the power level of the one or more laser energy sources at the first power level for a third predetermined distance following a first end portion of the second scan; decreasing, at an end of the third predetermined distance, the power level of the one or more laser energy sources from the first power level to the second power level lower than the first power level; maintaining the power level of the one or more laser energy sources at the second power level for a fourth predetermined distance; and increasing the power level of the one or more laser energy sources to the first power level at an end of the fourth predetermined distance.

18. The method of claim 10, wherein the second scanning orientation is perpendicular to the first scanning orientation.

19. The method of any one of claims 10-18, further comprising fusing the melted portion of precursor material to form one or more parts on the build surface.

20. A part manufactured using the method of any one of claims 10-19.

21. At least one non-transitory computer readable medium storing instructions, that when executed by at least one processor, cause the at least one processor to perform a method of additive manufacturing comprising: directing laser energy from one or more laser energy sources through an optics assembly and toward a build surface; 12486774.1melting at least a portion of a layer of material on the build surface due to exposure of the portion to the laser energy; and controlling a geometry of melt pools at end portions of scanning trajectories followed by the one or more laser energy sources, a first scanning trajectory of the scanning trajectories including one or more first scans in a first scanning orientation and a second scanning trajectory of the scanning trajectories including one or more second scans in a second scanning orientation, wherein controlling the geometry of melt pools comprises: controlling one or more parameters of the one or more laser energy sources at end portions of the one or more first scans in the first scanning orientation and at end portions of the one or more second scans in the second scanning orientation.

22. The at least one non-transitory computer readable medium of claim 21, wherein controlling the geometry of the melt pools comprises controlling a shape and / or size of the melt pool at the end portions of the scanning trajectories. 12486774.1

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