Laser arrays for laser powder bed fusion processing of metal alloys

Abstract

The present invention relates to a laser array for laser powder bed fusion processing of metal alloys. A system and method for additively manufacturing an object by applying heat to a first plurality of metal particles in a powder bed using a first heat source, wherein the first heat source is one of a plurality of heat sources configured in an array, and the first heat source produces a first molten pool. Heat is simultaneously applied to a second plurality of metal particles in the powder bed using a second heat source from the plurality of heat sources in the array to produce a second molten pool. The first plurality of metal particles are separated from the second plurality of metal particles by a distance, wherein the distance and the amount of heat from each heat source are controlled to produce a combined molten pool that is larger in size and surrounds the first molten pool and the second molten pool. The combined molten pool is allowed to solidify to form an object.

Description

Technical Field

[0001] The present application relates to laser arrays for laser powder bed fusion processing of metal alloys. Background Art

[0002] In recent years, various methods for additive manufacturing have been developed that are capable of relatively easily producing three-dimensional (3D) formed objects having complex shapes. One example of additive manufacturing is powder bed fusion that allows high forming accuracy and high bonding strength between laminated layers. In this way, the powder bed fusion method can be used not only to manufacture a prototype for confirming the shape or performance of the final product, but also to manufacture the final product.

[0003] In powder bed fusion, the layers of the shaped object are defined by finely dividing the three-dimensional shaped object in the thickness direction, which is generally referred to as layering or slicing. In order to start building, a powder material (including a resin material or a metal material) containing particles is spread flatly to form a thin layer, a desired position on the thin layer is irradiated with a laser, and the particles containing the powder material are selectively sintered or melted to combine them with each other (hereinafter, the combination of particles by sintering or melting is referred to as "fusion") to form one of the defined layers. According to the definition of the layer, the powder material is further spread on the layer thus formed, and irradiated with a laser to selectively fuse the particles contained in the powder material, thereby forming the next shaped object layer. By repeating this process and laminating the shaped object layers, a three-dimensional shaped object having a desired shape is manufactured.

[0004] The control of the laser in powder bed fusion (L-PBF) results in the volatile nature of the molten pool produced using traditional single laser spot power delivery. Other inherent disadvantages of the single laser spot method are perforation, insufficient fusion between layers due to the solidified molten pool geometry, spatter and smoke generation, etc. Therefore, in this traditional method, the concentration of high linear energy density in a small-sized spot results in excessive energy concentration applied to the powder layer, causing a volatile molten pool that causes defects. The most common defect is perforation, in which the conductive melting mode changes to a condition in which the molten metal evaporates and produces pores within the structure, allowing energy to penetrate to a much deeper depth than in the conductive mode, thereby capturing the produced pores during rapid solidification. Fusion defects also occur when the molten pool does not sufficiently overlap with the previous layer or line, resulting in unmelted areas. The highly concentrated energy via a single spot also results in the generation of thermal gradients during rapid melting and rapid solidification, thereby causing residual stresses in the manufactured parts. These stresses can cause distortion or even cracks during or after processing.

[0005] There is a need to perform powder bed fusion that is less volatile and makes the manufacture of parts more controllable and reliable. Summary of the invention

[0006] Some implementations include a method for additively manufacturing an object. The method includes applying heat to a first plurality of metal particles in a powder bed using a first heat source, wherein the first heat source is one of a plurality of heat sources configured in an array, and the first heat source produces a first molten pool. The method also includes applying heat to a second plurality of metal particles in the powder bed simultaneously using a second heat source from the plurality of heat sources in the array to produce a second molten pool. The first plurality of metal particles are separated from the second plurality of metal particles by a distance, wherein the distance and the heat from each heat source are controlled to produce a combined molten pool that is larger in size and encompasses the first molten pool and the second molten pool. The method also includes allowing the combined molten pool to solidify to form an object.

[0007] Some implementations include an additive manufacturing system comprising a powder bed configured to receive a coating of metal particles and a heat source array comprising at least a first heat source and a second heat source. The first heat source is configured to apply heat to a first plurality of adjacent metal particles in the coating to produce a first molten pool, and the second heat source is configured to apply heat to a second plurality of adjacent metal particles in the coating to produce a second molten pool. The first plurality of adjacent metal particles are separated from the second plurality of adjacent metal particles by a distance. The distance and the amount of heat from each of the heat sources are controlled to produce a combined molten pool that is larger in size and surrounds the first molten pool and the second molten pool.

[0008] Some implementations include one or more computer storage devices having computer executable instructions stored thereon, the computer executable instructions for operating a heat source during additive manufacturing, the computer executable instructions when executed by a computer causing the computer to perform operations, the operations comprising applying heat to a first plurality of metal particles in a powder bed using a first heat source. The first heat source is one of a plurality of heat sources configured in an array, the first heat source producing a first molten pool. The operations also include applying heat to a second plurality of metal particles in the powder bed simultaneously using a second heat source from the plurality of heat sources in the array to produce a second molten pool. The first plurality of metal particles are separated from the second plurality of metal particles by a distance. The distance and the amount of heat from each heat source are controlled to produce a combined molten pool that is larger in size and surrounds the first molten pool and the second molten pool. The operations also include allowing the combined molten pool to solidify to form the object. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings, in which like reference numerals refer to like parts throughout the several views, and in which:

[0010] Figure 1 A powder bed fusion additive manufacturing (AM) system using an array of heat sources according to examples of the present disclosure is shown.

[0011] Figure 2 A powder bed fusion AM system using a heat source array according to another example of the present disclosure is shown.

[0012] Figure 3 A laser array according to an example of the present disclosure is shown.

[0013] Figure 4 A laser array according to another example of the present disclosure is shown.

[0014] Figure 5 Operation of a powder bed fusion AM system using an array heat source according to an example of the present disclosure is shown.

[0015] Figure 6 The melting depth of the molten pool formed using different heat source array arrangements is shown.

[0016] Figure 7 A hot spot configuration produced according to an example of the present disclosure is shown.

[0017] Figure 8 A heat spot configuration with eight heat spots generated by a heat source according to an example of the present disclosure is shown.

[0018] Fig. 9 Different power configurations for producing a hot spot according to examples of the present disclosure are shown.

[0019] Fig.10 is a flow chart of a method for additively manufacturing an object according to an example of the present disclosure.

[0020] Fig.11 is a flow chart illustrating a method for aircraft manufacturing and service according to an implementation.

[0021] Fig.12 is a schematic perspective view of an aircraft according to an example of the present disclosure.

[0022] Fig.13 is a functional block diagram illustrating a computing device according to an example of the present disclosure.

[0023] Throughout the drawings, corresponding reference numerals indicate corresponding parts according to the various examples.

[0024] It should be noted that some details of the drawings have been simplified and are drawn to facilitate understanding of the present teachings rather than maintaining strict structural accuracy, detail, and scale. DETAILED DESCRIPTION

[0025] When reading in conjunction with the accompanying drawings, the following detailed description of the preceding summary of the invention and certain embodiments will be better understood. As used herein, the elements or steps described in the singular and preceded by the word "one" or "one" should be understood as not necessarily excluding the plural number of elements or steps. In addition, reference to "an embodiment", "a construction", "an example" or "an implementation" is not intended to be interpreted as excluding the existence of additional embodiments, constructions, examples or implementations that also incorporate the described features. In addition, unless explicitly stated to the contrary, the embodiment of "including" or "having" an element or multiple elements with a specific performance may include additional elements that do not have the performance.

[0026] Although various spatial and directional terms such as "top", "bottom", "upper", "lower", "vertical", etc. are used to describe the inventive aspects of the present disclosure, it should be understood that these terms are used only with respect to the orientation shown in the drawings. The orientation can be reversed, rotated, or otherwise changed so that if the structure is flipped 180 degrees, the top side becomes the bottom side, if the structure is pivoted 90 degrees, the top side becomes the left or right side, and so on.

[0027] Implementations of the present disclosure include arrays of heat sources (e.g., lasers) for powder bed fusion AM processes. The disclosed array arrangements (directly applied to or projected onto a powder bed) are configured for processing metal alloys, particularly titanium and titanium alloys.

[0028] Some implementations of array patterns allow for improved heat distribution for melting metal powders, including eliminating or reducing some of the problems of single laser spot approaches. Additionally, the present disclosure allows laser arrays to utilize the latent heat generated by individual laser spots in the array, rather than allowing for rapid dissipation that occurs during single laser spot processing. As a result, increased melting rates can be achieved.

[0029] In general, examples of the present disclosure provide for the delivery or projection of multiple laser spots in close proximity within a specified or defined array pattern / geometry to control melt pool stability, which can address fundamental shortcomings of conventional methods while providing a well-controlled melt pool that allows defect-free processing. Shared heat within the array area also allows for increased productivity of the L-PBF process and the potential use of a wider powder fraction distribution.

[0030] Figure 1A powder bed fusion AM system 100 using an array heat source according to an example of the present disclosure is shown. It should be understood that the implementation of the AM system 100 is shown for illustration only, and other implementations may be used in conjunction with the laser array configuration and laser control methods described herein. That is, powder bed fusion systems of different types and arrangements may be used with the present disclosure.

[0031] In the illustrated example, the powder bed fusion AM system 100 includes a heat source, shown as a laser system 102, which is configured as a laser array, such as Figure 3 . The laser system 102 is shown for illustration only, and other suitable heat sources capable of producing a beam or heat zone of sufficient energy to melt the powder may be used. In one example, the powder bed fusion AM system 100 includes one or more optical components, which are shown as a mirror 104 (e.g., a tilted mirror with focusing capability) to direct radiation from the laser system 102 to a target location 106 in a build space 108 to build an object 110. The powder bed fusion AM system 100 also includes a powder delivery system 112, which is configured to store powder 114 and deliver powder 114 to a build space 108 for manufacturing an object 110, such as by generating multiple melt pools 118 and 120, as described in more detail herein. In some examples, a spreader 116 is provided, and the spreader is configured to spread powder 114 from the powder delivery system 112 to the build space 108.

[0032] Figure 2 is another example of an AM system, shown as a powder-fed AM system 200, in which a heat source constructed in accordance with the present disclosure is implemented. Again, Figure 2 are non-exclusive examples and are configured to perform and / or facilitate the methods described herein. The AM system 200 generally includes an additive manufacturing machine having a deposition device 202. The deposition device 202 optionally includes a stock material supply device 204 (e.g., for a powder feed or wire feed system). The stock material supply device 204 provides raw material (e.g., at least one base alloy) to the additive manufacturing head of the deposition device 202. For example, the material is ejected from one or more material output devices disposed in the additive manufacturing head. One or more material output portions may include various configurations, such as holes, nozzles, etc. One or more material output devices of the manufacturing head may include holes aligned with one or more connections or convergences of the laser output devices, as described in more detail herein. Therefore, in one implementation, a base alloy (e.g., titanium) is provided to the powder feed system. The base tray 210 carries a stock material supply device 222 (e.g., such as for a powder bed system).

[0033] In one implementation, and also with reference to Figure 3 , forming a molten pool according to the methods described herein includes exposing at least a portion of the base alloy (e.g., the first and second pluralities of metal particles or portions of the metal particles) to a plurality of beams of focused energy (e.g., a plurality of heat sources). Examples of focused energy include electron beams, laser beams, and thermal radiation. In the illustrated example, the laser source 224 (which may be implemented similar to Figure 1 Laser system 102) such as using laser array 300 (in Figure 3 ) to generate multiple laser beams, and send the laser beams for emission via the laser output device of the additive manufacturing laser head 302. The laser beams emitted from the laser output device are concentrated to multiple connections or convergences. Therefore, in some examples, the deposition device 202 includes an energy source for emitting energy to raw materials provided by the material supply device. In one configuration, the deposition device 202 provides a focused beam of energy from the energy source to form multiple molten pools with raw materials provided by the inventory material supply devices 204, 222. For example, raw materials are released from one or more material output devices and enter the connection or convergence of the laser output device, and at least a portion of the material / raw material provided at the connection or convergence is melted to form a molten pool. In some examples, the laser output device works as a heat source to apply heat simultaneously to produce multiple molten pools. As described in more detail, the present disclosure contemplates different laser array configurations and laser movement controls.

[0034] In operation, at least a portion of the molten pool is deposited layer by layer using an AM process. That is, a deposited layer 206 is formed on a base tray 210. In some examples, the deposited layer 206 is deposited in a predetermined pattern and cooled during the process of forming the in-process article 208. In other words, as the laser source 224, which in one example includes an additive manufacturing laser head 302 having a laser array 304, is advanced relative to the product being formed, once the material leaves the weld pool, for example, after being deposited onto a substrate or onto a previously deposited layer of molten pool material, the molten material of the molten pool begins to cool and harden (i.e., solidify).

[0035] To assist in forming the layer 206 on the base tray 210, in one implementation, the deposition device 202 is translated along the lateral stage 212, and the base tray 210 is translated along the axial or vertical stage 214. The AM system 200 optionally includes a manufacturing chamber 216 surrounding the deposition device 202, the base tray 210, and the formed layer 206. It should be understood that the present disclosure contemplates different types and configurations or movements of one or more different components. For example, the laser array 304 is operable to move together (or independently) in one or more directions and at different speeds.

[0036] In one example, the deposition device 202 is configured to move away from the base tray 210 and the article in process 208, leaving a clear path for non-contact. Additionally or alternatively, the deposition device 202 provides a clear path for a portion of the article in process 208 and can be moved relative to the article in process 208 to sequentially expose all portions of the article in process 208. The AM system 200, including one or more of its components, is controlled by a controller 218, which in some examples is configured as a computer 220. The controller 218 coordinates the operation of the deposition device 202 (and other components) and can be programmed to perform any of the manufacturing methods shown and described herein (e.g., using a dual-axis gantry system).

[0037] It should be noted that the additive manufacturing apparatus may be available or modifiable to complete the formation of the part in the same chamber as the deposition apparatus. Melting may include exposure to an electron beam, plasma, arc, laser energy, contact flame, etc. Examples of base alloys include metal / metal alloys, such as titanium-based alloys. Examples of titanium alloy powders include, but are not limited to, a titanium powder known as Ti-6Al-4V, which contains approximately 90% titanium alloyed with approximately 6% aluminum and approximately 4% vanadium.

[0038] The base alloy for various examples can be provided in the form of wire, powder or liquid or a combination thereof. The base alloy wire can be provided in any size or combination of sizes without limitation, such as used by the AM system 200. In one example, the base alloy wire is provided in a size of up to one-eighth inch. The powder can contain one or more base alloy particles. The base alloy particles can be provided in any size or combination of sizes without limitation. For example, the original base alloy can be in powder form, including particles with a size from about 10 microns to about 250 microns, such as from about 45 microns to about 105 microns, including particles from about 10 microns to about 45 microns. The base alloy particles provided within this size range provide better fluidity and easier melting, resulting in a more evenly distributed powder and a more evenly distributed modified alloy chemical properties. Therefore, although many processing systems, such as lasers or electron beam systems are configured to melt powders with particles with a size in the range of about 10 microns to about 250 microns, other sizes can also be used. The base alloy particles can be provided in any shape or combination of shapes without limitation. For example, the original base alloy particles may be in the form of a powder, including particles in the shape of spheres, sponges, flakes, and the like.

[0039] In various examples, the heat generated by the laser array 304 is controlled to effectively form a plurality of molten pools. That is, the laser array 304 is configured as a heat source that generates heat sufficient to melt the base alloy particles.

[0040] In the example shown, the positioning of the laser arrays 304 relative to each other and along the additive manufacturing laser head 302 is individually and independently adjustable. Figure 3 As shown in FIG. 3 , screws 306, 308, and 312 are configured to adjust each laser 310 of the additive manufacturing laser head 302. In this example, screw 308 is a horizontal screw or side screw that is adjustable to lock each of the lasers 310 to the additive manufacturing laser head 302. That is, screw 308 allows for the coupling and "rough" positioning of the laser 310 on the additive manufacturing laser head 302. Screw 306, shown as a vertical screw, allows for "fine" adjustment of the positioning of the laser 310 in the additive manufacturing laser head 302. Thus, the lasers 310 of the laser array 304 are configured for precise positioning relative to each other and within the additive manufacturing laser head 302. Screw 312 allows the laser to move inward and outward. In one example, for a beam diameter of 120 micrometers (μm), screws 306, 308, and 312 allow for x-direction adjustment, y-direction adjustment, and z-direction adjustment to position the laser within a maximum error of 10 μm. Thus, in the illustrated example, screws 306 and 308 allow for variable adjustment of the positioning of lasers 300 (eg, changing the alignment of one or more of lasers 300 ).

[0041] Therefore, a plurality of different screws 306 and 308 are provided to allow adjustment of the laser 304 in different directions or axes. In one example, the laser head 302 includes a plurality of screws that allow adjustment in the x-direction, the y-direction, and the z-direction.

[0042] It should be understood that the present disclosure contemplates different adjustment mechanisms. That is, the adjustment mechanism may include mechanical components, electrical components, optical components, or a combination thereof. In some examples, the adjustment mechanism for adjusting the laser 300 includes an actuator that can be controlled by programming. In one configuration with an actuator, the controller 218 is programmed to control the positioning of the laser 300 (e.g., change the position of the laser 300), such as based on a specific application. It should be noted that the laser 300 can be adjusted before, during, and / or after the AM operation. Therefore, the present disclosure contemplates the adjustment of different control mechanisms at different times and using different control mechanisms that can allow automatic adjustment, semi-automatic adjustment, and / or manual adjustment. For example, in one configuration, the physical positioning of the laser 306 is manually adjusted to define a fixed array before the AM operation. Thereafter, optical devices and optical control devices known in optical technology are used to adjust the relative position of the laser beam. In one example, an optical window is used and configured to move to adjust the direction of one or more of the laser beams generated by the laser 306.

[0043] In some examples, additional adjustments are contemplated, such as tilt adjustments of the lasers 310. However, in other examples, the tilt angle of each of the lasers 310 is fixed by the configuration of the additive manufacturing laser head 302 (eg, the alignment positions of the lasers 310).

[0044] Different configurations for regulation are envisaged, e.g. Figure 4 4. In this example, screws 452 and 454 are individually and independently adjustable to change the positioning of a laser collimator holder 456 that holds a laser collimator 458, such as that provided by laser 310 ( Figure 3 In the illustrated configuration, screws 452 and 454 are adjustable to allow rotation of laser collimator 458 about ball joint 460 (as indicated by arrow R). That is, screws 452 and 454 allow movement of laser collimator holder 456, which allows laser collimator 458 to be rotated as shown in FIG. Figure 4 Thus, in some examples, adjustment of the laser spot position can be made via screws 452 and 454, which directly apply force to the laser collimator holder 456 (e.g., a laser collimator holding tube) and / or bear on the 45 degree element to distribute the locking force horizontally and vertically.

[0045] Additional adjustments may be performed in some examples. For example, in one arrangement, the laser collimator holder 456 is also configured to allow the laser collimator 458 to be adjusted as shown in FIG. Figure 4 46 and 47. The laser collimator 458 is moved in an up and down translational manner (indicated by arrow T) as seen in FIG. 46. That is, the laser collimator holder 456 is configured to allow the laser collimator 458 to move longitudinally therein. Movement of the laser collimator 458 may be accomplished using any suitable actuator and control device, illustrated as a control arm 462 and locking teeth 464, which move the laser collimator 458 and secure the laser collimator 458 in a fixed position within the laser collimator holder 456.

[0046] It should be understood that different types and kinds of adjustment mechanisms may be used to cause different types and kinds of movement, such as to allow different positioning and orientations of the lasers 310. Thus, various examples allow for individual adjustment of the lasers 310, as well as the spot size and position of all lasers 310, such as in a mechanism for changing their X, Y, and / or Z positions.

[0047] It should also be understood that different configurations of lasers are contemplated. For example, while the laser array 304 is shown as having eight lasers 310 configured as two rows of four lasers 310, the present disclosure contemplates different configurations. For example, a different number of lasers 310 may be used for additional or fewer rows. That is, configurations of lasers 310 of different shapes and sizes (e.g., different geometries of lasers 310) may be used. For example, Figure 5 A laser array 400 is shown that is configured as a heat source for use with a powder bed fusion AM system. The laser array 400 is arranged in a single column that moves relative to a build space 402 (as shown by the arrow). In some examples, the laser array 400 configured as a heat source is fixed and the build space is movable. Figure 5 As shown in , the laser array 400 includes six lasers 404 that emit six laser beams 404 that produce multiple molten pools that are subsequently combined into a larger molten pool in some examples. It should be understood that the movement of the laser array 400 can vary in time and space, such as moving in different directions and at different speeds. The movement of the laser array 400 can include simple linear movement or more complex movement, such as displacement or rotation / pivot movement.

[0048] Furthermore, different geometries of lasers 310 may include different one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) arrangements. Different geometries of lasers 310 may include lasers 310 that are symmetrically and / or asymmetrically aligned, offset, shifted, staggered, etc. That is, the present disclosure contemplates a variety of different shapes, sizes, locations, orientations, etc. of lasers 310.

[0049] Figure 6 A graph 500 of depth of melt comparison is shown, which shows the extent of the molten pool for different heat source array arrangements. A single pass of a one-dimensional array of five lasers is used to produce a molten pool 502, and five passes of a single laser are used to produce a molten pool 504. Molten pools 502 and 504 show cross-sections of the melted forms formed by each heat source array arrangement. That is, the molten pool 502 is formed by five parallel lasers, and the molten pool 504 is formed by a single laser that makes five passes (at different times). As can be seen, the sum of the cross-sectional areas of the molten pool 504 produced by five separate single laser passes (the sum of the areas subtended by the corresponding lines) is much smaller than the cross-sectional area of ​​the molten pool 502 obtained by passing through a spaced-apart, simultaneous linear array of five lasers (the area subtended by the corresponding lines). Therefore, the present disclosure produces an enlarged molten pool in some examples, which is achieved in a shorter period of time than using a single laser (e.g., the proximity of the laser beams allows faster melting than a single beam operated in multiple passes).

[0050] In various examples, and as should be understood from viewing graph 500, the present disclosure thus also provides heat sharing as shown by the melting isotherms. It should be noted that the molten pools 502 and 504 show velocities that match depth.

[0051] Different configurations of laser arrays 600 Figure 7 It should be noted that although the figure shows a hot spot configuration generated by a laser array having eight lasers, different numbers of lasers can be used, including odd and even numbers of lasers. Different hot spot configurations correspond to lasers arranged in a pattern similar to the heat source to generate a hot spot. That is, the geometry of the lasers generating the hot spot is arranged to be the same geometry (e.g., oriented) as the generated hot spot 612.

[0052] More specifically, Figure 7 An 8×1 configuration shown at 602, a 4×2 configuration shown at 604, a 3×2×3 configuration shown at 606, a 2×4 configuration shown at 608, and a 1×8 configuration shown at 610 are shown. Lasers of different geometric shapes can be used to produce other hot spot configurations. For example, for four hot spot configurations, the hot spots can be arranged in 4×1, 2×2, or 1×4 configurations. Therefore, the present disclosure contemplates a configuration with multiple rows and columns, which can be different numbers, such as to define an asymmetric configuration or a non-rectangular configuration (for example, two rows have a first number of lasers and one row has a second different number of lasers). That is, different rows and / or columns, or subsets of rows and / or columns, can have different numbers of lasers therein. In some examples, alternating rows and / or columns of different numbers of lasers are set. In other examples, rows / columns with different numbers of lasers are arranged in different non-repeating or non-alternating configurations.

[0053] It should be understood that the characteristics and performance of the hot spot 612 can vary based on the operating configuration and parameters of the laser. For example, the temperature generated by the laser and the distance between the lasers (or the distance between the corresponding generated hot spots 612) can be changed based on the desired or required pattern or geometry of the hot spot 612 (including the size of the hot spots 612, the spacing between them, the temperature, etc.). Therefore, by changing the operating parameters of the laser or the physical arrangement of the laser, the characteristics and performance of the hot spot 612 are adjusted, which results in different characteristics or performance of the generated molten pool (e.g., the size of the molten pool, the time to generate the molten pool, etc.).

[0054] For example, Figure 8A hot spot configuration 700 according to an example of the present disclosure is shown, which includes eight hot spots 710 generated by a plurality of heat sources (e.g., lasers) arranged in two columns and four rows (2×4). The arrangement of the heat sources defines the geometry of the hot spots 710, including column spacing 702, row spacing 704, and spot diameter 706 in some examples. That is, the performance of the geometry of the hot spot configuration 700 is defined by the geometry of the laser that generates the hot spot 710. In operation, the hot spot configuration 700 can be moved in a scanning direction 708, as shown by the arrow. However, it should be understood that different scanning directions can be envisioned. Moreover, in the case of selecting parameters as described herein, the hot spots 710 are non-overlapping.

[0055] Furthermore, the operating characteristics of the laser can be adjusted, for example to provide Fig. 9 Different power configurations 800 of the hot spot shown. That is, the power of lasers (or a single laser) in different rows and / or columns can be adjusted to define different power configurations 800, or other configurations. In the example shown, configuration 802 provides higher power in the front column 808 (than in the rear column 810), the rectangular configuration 804 provides equal power in both columns 808 and 810, and the configuration 806 provides lower power in the front column 808 (than in the rear column 810). Therefore, the relative heat generated by the lasers in different columns and / or rows can be adjusted as required or needed by adjusting one or more properties of the lasers that generate the hot spot. In one example, the minimum and maximum power levels (e.g., 40 watts (W) and 400W) of the lasers operating at full power in each column are defined. The power level can also be adjusted, for example, based on the feed rate of the powder inventory. In one example, for a lower feed rate, such as 66 millimeters per second (mm / s), a power level of 1.6 joules (J) / mm was used, resulting in a total power of 105 W. However, other power level and feed rate combinations are contemplated. For example, in some examples, a power level of 218 mm / s and 1.66 J / mm was used, resulting in a total power of 363 W, or in other examples, a power level of 443 mm / s and 0.86 J / mm was used, resulting in a total power of 381 W. The power level and feed rate were adjusted in various examples to provide suitable substrate penetration and stability.

[0056] Thus, columns can have different power levels. In some examples, front-end preheating is used with back-end cooling. It should be understood that power levels can vary across different columns as required or desired. In some examples, all of the spots in a particular column have a first power, and all of the spots in a second column have a different second power. However, one or more spots in each column may have a different power than one or more spots in the same column.

[0057] It should be understood that although Fig. 9 A 2×4 hot spot configuration is shown, but this is only a non-limiting example. Other numbers of hot spots may also be arranged in the configuration described herein (or other configurations) in accordance with the present disclosure. It should be noted that in various examples, the heat sources are controlled to produce non-overlapping hot spots.

[0058] Therefore, the laser array configured as a heat source of the present disclosure can be varied to simultaneously produce different molten pools during the AM process. The geometry of the laser and other characteristics or operating parameters of the laser can be varied to produce different geometries and patterns of the hot spots, for example, hot spots with different spot sizes, spot spacings, and column spacings. In some examples, the spot size, spot spacing, and column spacing may vary between 150 μm and 300 μm. However, it should be understood that other ranges of values ​​are contemplated. In one example, for a column of lasers with a total length of 1.4 mm, a hot spot diameter of 150 μm is produced, with a spacing of 250 μm between the hot spots. It should be noted that the values ​​of each of the spot size, spot spacing, and column spacing may be the same or different.

[0059] Furthermore, modeling of the heat sharing process indicates that heat sharing occurs when the residual heat stored in the parallel melt pools allows those melt pools to merge before solidification occurs. This process allows several small laser sources to act as if they were one large laser source.

[0060] Based on modeling predictions, experiments were conducted to show the benefits of using a multi-spot array of a laser to perform LPBF additive manufacturing. The array geometry variables were kept constant while the number of spots was systematically varied. The power-feed rate combination was kept constant for all spot numbers. The hatch distance percentage was kept as close as possible across each array.

[0061] The results show that the highest normalized melt rate at which 99.99% density can be achieved increases logarithmically as spots are added to the array. The largest increase in both parameters occurs with the addition of the second spot, followed by smaller increases for each additional spot.

[0062] These results show that heat sharing occurs between the individual lasers, leading to a significant increase in process efficiency. Although the efficiency gain is asymptotically limited after 8 to 10 lasers, adding any number of lasers can still significantly increase the absolute melting rate.

[0063] Table 1 and Table 2 show the experimental results for various parameter combinations and the results from three data sets, respectively.

[0064] Table 1: Experimental parameter combinations

[0065]

[0066] Table 2: Parameter estimates for the Archimedean density response surface model

[0067] the term estimate Standard error t ratio Prob>|t| power 2.583 0.133 19.404 <0.0001 Spot size*spot interval 0.001 0.000 14.439 <0.0001 Feed rate*Feed rate 17.115 1.461 11.715 <0.0001 Power*Power -1.782 0.163 -10.900 <0.0001 Spot size*Spot size 0.000 0.000 -10.471 <0.0001 Spot size -0.063 0.007 -9.093 <0.0001 Feed rate 15.302 1.952 7.840 <0.0001 Feed rate*spot size -0.063 0.008 -7.486 <0.0001 Power*Spot Size 0.017 0.002 7.069 <0.0001 Spot interval*Spot interval 0.000 0.000 -4.632 <0.0001 Spot interval 0.019 0.004 4.293 <0.0001 Feed rate*spot spacing 0.021 0.006 3.736 0.0002 Hatching distance*hatching distance 0.000 0.000 -3.283 0.001 Hatching distance*spot interval 0.000 0.000 2.818 0.005

[0068] In one example, the model was optimized to achieve 100% density while minimizing volume energy density (VED) and maximizing melting rate. In this example, the optimal parameter combination was power = 116W, scan speed = 66mm / s, hatch distance = 1225μm, spot size = 75μm, spot spacing = 175μm. The VED, melting rate, and linear energy density (LED) associated with this combination were 76.2J / mm3, 196.5g / h, and 1.8J / mm, respectively.

[0069] In some examples, VED is calculated to determine various operating characteristics of the laser. It should be noted that VED and melting rate (MR) are inversely related. VED can be expressed as follows:

[0070]

[0071] Let Units be:

[0072]

[0073] Where P is the laser power, v is the scanning speed (mm / hour), and t is the powder layer thickness (mm). MR can be expressed as follows:

[0074] MR=ρνth (2)

[0075] And can be expressed as:

[0076]

[0077] Let Units be:

[0078]

[0079] Where ρ is the material density. As can be seen in the above equations, (i) increasing the laser power increases VED, and (ii) increasing the scan speed, hatch spacing, or layer thickness decreases VED. Therefore, if one wishes to increase the melting rate, one can increase the power and decrease VED by increasing t, v, or h, or by heat sharing in an array of heat sources with separate spots (subject to the limitation of 99.99% density). In one example, the following parameters are used to generate the density of the laser spot:

[0080] Feed rate = 40 mm / s;

[0081] Power = 200W;

[0082] Density = 99.99%;

[0083] hatch spacing = 0.9 mm;

[0084] Powder layer = 100 μm; and

[0085] VED=55.5J / mm 3 .

[0086] In one example, according to the present invention, a melting rate of greater than 500 g / h at 3.2 kW, a density of 99%, and a pore size of less than 50 μm were obtained. It should be understood that various parameters can be controlled according to the present disclosure to control the generation of the laser spot. For example, parameters such as power, feed rate, and hatching distance can be varied as required or needed, such as for a specific application. In some examples, one or more of the spot size, spot spacing, power, feed rate, and hatching distance can be adjusted manually or automatically. In one example, the parameters are selected so that the parallel molten pools merge before solidification.

[0087] In some examples, the laser power was 200 W, the beam diameter was 150 μm, and the feed rate was 150 mm / s. In five separate passes of a single laser, different molten pools were formed (see Figure 6 ). As will be appreciated, the extent of each melting isotherm is proportional to the laser power and inversely proportional to the feed rate and how much energy is conducted away from the interaction (determined primarily by the thermal conductivity and diffusivity of the material). In an LPBF system, the temperature of the substrate at a given point cools significantly between one pass of the laser beam past the given point and the next. As a result, each pass effectively passes over the substrate at the same temperature, and each melt pool has the same shape and size as the melt pool produced by the previous pass of the beam.

[0088] With the present disclosure using multiple laser beams, and continuing with the example above, using five simultaneous beams, the vertical conduction losses down into the bulk of the material are the same as with a single beam. Therefore, the maximum depth of melting is slightly greater than that obtained with a single beam. However, the horizontal conduction losses are reduced, and the molten pool of each beam is enlarged by the heat added by the adjacent beams. This results in a larger molten pool for each beam, and a single molten pool can be produced using parameters selected as described herein. It should be understood that as the feed rate increases, there is less time available for heat sharing, and the molten pools can begin to separate. In addition, with heat sharing using the present disclosure, the spacing of the beams in a parallel array can (and will for optimized efficiency) exceed the hatch spacing required for a single beam system.

[0089] Thus, using the present disclosure, the multi-spot array configuration improves melting efficiency compared to a single spot configuration. It was determined that the normalized melting rate at 99.99% density increases with each additional laser. The point representing one laser is a baseline value at 13.3 g / h / 100W. With the addition of a second laser, this value increases to 31.9 g / h / 100W. This is a factor of 2.4 and indicates that the two lasers working together are more than twice as efficient as a single laser. This value increases logarithmically for each additional laser, stabilizing at a value of 38.2 g / h / 100W. This is equivalent to a 2.9-fold increase in overall efficiency.

[0090] Fig.10 900 is a flow chart of a method 900 for additive manufacturing an object according to an example of the present disclosure. The method can be performed using any of the examples described or contemplated herein. In addition, one or more steps of the method 900 can be performed in a different order, and additional or fewer steps can be provided. One or more steps can be performed simultaneously, in parallel, or sequentially.

[0091] Method 900 includes applying heat to a first plurality of metal particles in a powder bed using a first heat source at 902. The first heat source is one of a plurality of heat sources configured in an array and produces a first molten pool. For example, Figure 3 As shown, the laser 310 is configured as a heat source and generates a hot spot that melts the powder at a target location (such as Figure 7 That is, each of the lasers 310 is configured to generate a beam that generates heat to melt the powder and form a molten pool (e.g., one of the lasers 310 is configured to form a Figure 1 The first molten pool of the molten pool 118 shown in FIG. 1 ).

[0092] The method 900 also includes, at 904, simultaneously applying heat to a second plurality of metal particles in the powder bed using a second heat source in the plurality of heat sources in the array to generate a second molten pool (e.g., Figure 1 120). In one example, the first plurality of metal particles are separated from the second plurality of metal particles by a distance. The distance and amount of heat from each heat source are controlled to produce a combined molten pool that is larger in size and surrounds the first molten pool and the second molten pool. For example, the first heat source and the second heat source are multiple lasers, and the first heat source and the second heat source simultaneously melt the powder at two different locations to form two molten pools, which will solidify to form an object or a portion of an object. That is, method 900 also includes allowing the combined molten pool to solidify to form an object or a portion thereof at 906.

[0093] It should be noted that in some examples, applying heat to the metal particles includes applying heat to particles of titanium or a titanium alloy.

[0094] In some examples, method 900 includes using additional heat sources in the array to produce corresponding additional molten pools having corresponding changes in size relative to the combined molten pool at 908. For example, the array is configured in an (m×m) configuration or an (n×m) configuration, where n is less than m. However, as described herein, other configurations are contemplated, such as having rows or columns with different numbers of lasers, resulting in a non-rectangular array configuration or an asymmetric array configuration.

[0095] The size of the combined molten pool is determined based on the number of heat sources in the array applying heat and the operating characteristics or performance of the laser as described herein. In examples utilizing additional heat sources in the array, using the additional heat sources in the array to produce the combined molten pool also includes controlling which heat sources in the array apply heat to expand and shape the combined molten pool at 910.

[0096] In some examples, method 900 also includes adjusting the relative positions of the first heat source and the second heat source to adjust the mechanical properties of the object produced by the combined molten pool at 912. For example, adjusting the spacing and / or alignment of the lasers.

[0097] In some examples, method 900 also includes, at 914, moving the array relative to the powder bed in a first direction such that the combined molten pool moves across the powder bed in the first direction as the previous combined molten pool positions solidify (see, e.g., Figure 5 ). That is, the movement of the laser also causes the molten pool to move.

[0098] In some examples, applying heat at 902 also includes moving the array relative to the powder bed in a scan direction at 916. The scan direction movement may be a linear movement or other types of movement as described herein.

[0099] In some examples, applying heat at 902 also includes separating the first heat source and the second heat source at the powder bed by a distance corresponding to the spot size of the heat source at the powder bed at 918. That is, the lasers are separated to produce a desired or required spacing between the heat spots.

[0100] Although aspects of the disclosure have been described in terms of various implementations and their associated operations, those skilled in the art will appreciate that combinations of operations from any number of different implementations are also within the scope of aspects of the disclosure.

[0101] Thus, the present disclosure allows the use of a laser array pattern / design of multiple spots to produce a molten pool, such as in L-PBF, as opposed to using multiple lasers to produce a molten pool using a single spot. Utilizing the arrangement of multiple spots, the present disclosure achieves optimized molten pools and processing conditions for specific alloys (e.g., titanium and titanium alloys) in various examples.

[0102] Exemplary Operating Environment

[0103] This disclosure may be made in accordance with Fig.11 1000. During pre-production of an aircraft, some implementations of method 1000 include specification and design of the aircraft at operation 1002, and material procurement at operation 1004. During production, some implementations of method 1000 include component and subassembly manufacturing at operation 1006 and aircraft system integration at operation 1008. The aircraft undergoes certification and delivery at operation 1010 to be placed in service at operation 1012. While in use by a customer, the aircraft is scheduled for routine maintenance and repair at operation 1014. In some implementations, operation 1014 includes modification, reconfiguration, refurbishment, and other operations associated with maintaining the aircraft in an acceptable safety condition during ongoing flight operations. Systems and methods for additive manufacturing as disclosed herein are used during, for example, operations 1006 and / or 1014.

[0104] Each process of method 1000 may be performed or implemented by a system integrator, a third party, or an operator (e.g., a customer). For purposes of this disclosure, system integrators include any number of aircraft manufacturers and main system subcontractors; third parties include any number of suppliers, subcontractors, and vendors; operators include airlines, leasing companies, military entities, maintenance organizations, and similar entities that provide similar sales and leasing services.

[0105] The present disclosure may operate in a variety of terrestrial and off-terrestrial environments for a variety of applications. For illustrative purposes only, and not intended to limit the possible operating environments in which implementations of the present disclosure may operate, the following exemplary operating environments are presented. Fig.12 1100, the present disclosure may be operated in an aircraft operating environment. Implementations of aircraft 1100 include, but are not limited to, fuselage 1102, multiple high-level systems 1104, and interior 1106. Some implementations of aircraft 1100 incorporate high-level systems 1104, including, but not limited to: one or more of propulsion system 1108, electrical system 1110, hydraulic system 1112, and environmental system 1114. Any number of other systems may be included in implementations of aircraft 1100. Although aerospace implementations are shown, the principles may be applied to other industries, such as the automotive and marine industries.

[0106] The present disclosure may be used in accordance with Fig.13The computing device 1202 may be operated together with an implementation of the functional block diagram 1200. In this implementation, the components of the computing device 1202 may be implemented as part of an electronic device according to one or more implementations described in this specification. The computing device 1202 includes one or more processors 1204, which may be microprocessors, controllers, or any other suitable type of processor for processing computer-executable instructions to control the operation of the electronic device. Platform software including an operating system 1206 or any other suitable platform software may be provided on the device 1202 to enable application software 1208 to be executed on the device. According to one implementation, the AM system described herein may be implemented at least in part by software.

[0107] Computer executable instructions may be provided using any computer readable medium accessible by the computing device 1202. Computer readable media may include, but are not limited to, computer storage media such as memory 1210 and communication media. Computer storage media such as memory 1210 include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer readable instructions, data structures, program modules, etc. Computer storage media include, but are not limited to, RAM, ROM, EPROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical storage, cassettes, tapes, disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information for access by a computing device. In contrast, communication media can implement computer readable instructions, data structures, program modules, etc. in modulated data signals such as carrier waves or other transmission mechanisms. As defined herein, computer storage media do not include communication media. Therefore, computer storage media should not be interpreted as propagating signals themselves. The propagated signals themselves are not examples of computer storage media. Although computer storage media (memory 1210 ) is shown as being within computing device 1202 , those skilled in the art will appreciate that the storage may be distributed or located remotely and accessed via a network or other communications link (eg, using communications interface 1212 ).

[0108] The computing device 1202 may include an input / output controller 1214, which is configured to output information to one or more output devices 1216, which in some implementations are displays or speakers and can be separated from or integrated into the electronic device. The input / output controller 1214 may also be configured to receive and process input from one or more input devices 1218, which in some implementations are keyboards, microphones, or touch pads. In one implementation, the output device 1216 also serves as an input device. A touch-sensitive display is one such device. The input / output controller 1214 may also output data to a device other than the output device, such as a locally connected printing device. In some implementations, a user may provide input to (one or more) input devices 1216, 1218 and / or receive output from (one or more) output devices 1216.

[0109] The functions described herein may be performed at least in part by one or more hardware logic components. According to one implementation, computing device 1202 is constructed by program code, and the program code, when executed by processor 1204, performs the implementation of the described operations and functions. Alternatively or in addition, the functions described herein may be performed at least in part by one or more hardware logic components. Without limitation, illustrative types of usable hardware logic components include field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), program-specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), and graphics processing units (GPUs).

[0110] Thus, various implementations include systems and methods for performing additive manufacturing.

[0111] Although various spatial and directional terms, such as top, bottom, lower, middle, side, horizontal, vertical, front, etc., may be used to describe the present disclosure, it should be understood that these terms are used only with respect to the orientation shown in the accompanying drawings. The orientation may be reversed, rotated or otherwise changed so that upper is lower and vice versa, horizontal becomes vertical, etc.

[0112] As used herein, a structure, limitation, or element that is "configured to" perform a task or operation is specifically structurally formed, constructed, or adapted in a manner corresponding to the task or operation. For clarity and avoidance of doubt, an object that can merely be modified to perform a task or operation is not "configured to" perform a task or operation as used herein.

[0113] As will be apparent to one skilled in the art, any range or value given herein may be expanded or altered without losing the effect sought.

[0114] Although the subject matter has been described in language specific to structural features and / or methodological acts, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as exemplary forms of implementing the claims.

[0115] It will be understood that the above benefits and advantages may relate to one implementation or may relate to multiple implementations. These implementations are not limited to those that solve every problem discussed in the background of this article, or those that have any or all of the benefits and advantages.

[0116] The implementations shown and described herein, as well as implementations not specifically described herein but within the scope of the claimed aspects, constitute exemplary apparatus for cold spray additive manufacturing with gas recovery.

[0117] Unless otherwise specified, the order of execution or performance of the operations in the implementation of the present disclosure shown and described herein is not essential. That is, unless otherwise specified, the operations can be performed in any order, and the examples of the present disclosure may include more or less operations than the operations disclosed herein. As an illustration, it is contemplated that it is within the scope of the various aspects of the present disclosure to perform or perform a particular operation before, simultaneously with, or after another operation.

[0118] When introducing elements of aspects of the present disclosure or implementations thereof, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements in addition to the listed elements. The term “exemplary” is intended to mean “an example of….” The phrase “one or more of: A, B, and C” means “at least one of A and / or at least one of B and / or at least one of C.”

[0119] Having described various aspects of the disclosure in detail, it will be apparent that modifications and variations are possible without departing from the scope of the various aspects of the disclosure as defined in the appended claims. As various changes may be made to the above-described constructions, products and methods without departing from the scope of the various aspects of the disclosure, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not limiting.

[0120] It should be understood that the above description is illustrative, not restrictive. As an illustration, the above implementations (and / or aspects thereof) can be used in combination with each other. In addition, without departing from the scope of the present disclosure, many modifications are feasible to adapt specific situations or materials to the teachings of various implementations of the present disclosure. Although the size and type of materials described herein are intended to limit the parameters of various implementations of the present disclosure, the implementation is by no means restrictive, but an exemplary implementation. After reading the above description, many other implementations will be obvious to those skilled in the art. Therefore, the scope of various implementations of the present disclosure should be determined with reference to the appended claims and the full scope of equivalents authorized by these claims. In the appended claims, the terms "including" and "wherein" are used as the plain English equivalents of the corresponding terms "including" and "wherein". In addition, the terms "first", "second" and "third", etc. are used only as marks and are not intended to impose numerical requirements on their objects. In addition, the limitations of the claims are not written in the format of device plus function, and are not intended to be interpreted based on 35 U.S.C. §112 (f), unless and until such claim limitations explicitly use the phrase "refers to" followed by a functional statement without additional structure.

[0121] This written description uses examples to disclose various implementations of the present disclosure, including the best mode, and also enables a person of ordinary skill in the art to practice the various implementations of the present disclosure, including making and using any device or system and performing any combined method. The patentable scope of the various implementations of the present disclosure is defined by the claims, and includes other examples that occur to a person of ordinary skill in the art. If these other examples have structural elements that are not different from the literal language of the claims, or if these examples include equivalent structural elements that are not substantially different from the literal language of the claims, then these other examples are intended to be within the scope of the claims.

[0122] Terms

[0123] The following clauses describe additional aspects:

[0124] Clause Group A:

[0125] A1. A method for additively manufacturing an object, the method comprising:

[0126] applying heat to a first plurality of metal particles in the powder bed using a first heat source, the first heat source being one of a plurality of heat sources configured in an array, the first heat source producing a first molten pool;

[0127] applying heat to a second plurality of metal particles in the powder bed simultaneously using a second heat source from the plurality of heat sources in the array to produce a second molten pool, the first plurality of metal particles being separated by a distance from the second plurality of metal particles, the distance and the amount of heat from each heat source being controlled to produce a combined molten pool that is larger in size and surrounds the first molten pool and the second molten pool; and

[0128] The combined molten pools are allowed to solidify to form the object.

[0129] A2. The method described in clause A1 further includes using additional heat sources in the array to generate corresponding additional molten pools, wherein the additional molten pools have corresponding changes in size relative to the combined molten pool, and the array is constructed as an (m×m) structure or a (n×m) structure, where n is less than m.

[0130] A3. The method of any of the preceding clauses, wherein the combined molten pool is sized based on a plurality of heat sources in the array that apply heat.

[0131] A4. The method of any of the preceding clauses, wherein using additional heat sources in the array to produce the combined molten pool includes selectively controlling the number of heat sources in the array that apply heat to expand the combined molten pool (502) and shape the combined molten pool.

[0132] A5. The method of any of the preceding clauses, further comprising adjusting the relative positions of the first heat source and the second heat source to adjust the mechanical properties of the object formed by the combined molten pool.

[0133] A6. The method of any of the preceding clauses, wherein applying heat comprises applying heat using a laser.

[0134] A7. The method of any of the preceding clauses, further comprising moving the array relative to the powder bed in a first direction such that the combined molten pool moves across the powder bed in the first direction as a previous combined molten pool position solidifies.

[0135] A8. The method of any of the preceding clauses, wherein applying heat to the metal particles comprises applying heat to particles of a titanium alloy.

[0136] A9. The method of any of the preceding clauses, wherein applying heat also controls the first heat source and the second heat source to produce a plurality of heat spots having a defined diameter and a defined spacing.

[0137] A10. A method as described in any of the preceding clauses, wherein applying heat further comprises separating the first heat source and the second heat source at the powder bed by a distance corresponding to a spot size of the heat source at the powder bed.

[0138] Clause Group B:

[0139] B1. An additive manufacturing system, comprising:

[0140] a powder bed configured to receive a coating of metallic particles; and

[0141] A heat source array, the heat source array comprising at least a first heat source and a second heat source, the first heat source being configured to apply heat to a first plurality of adjacent metal particles in the coating to produce a first molten pool, the second heat source being configured to apply heat to a second plurality of adjacent metal particles in the coating to produce a second molten pool, the first plurality of adjacent metal particles being separated from the second plurality of adjacent metal particles by a distance, the distance and the amount of heat from each of the heat sources being controlled to produce a combined molten pool that is larger in size and surrounds the first molten pool and the second molten pool.

[0142] B2. The additive manufacturing system of clause B1, wherein the heat source array comprises a laser array configured to generate a plurality of heat spots, each heat spot having a defined diameter and a defined spacing.

[0143] B3. The additive manufacturing system of any of the preceding clauses, wherein the heat source array is configured to move in a scanning direction relative to the powder bed.

[0144] B4. The additive manufacturing system of any of the preceding clauses, wherein the heat source array is configured as an (m×m) configuration or an (n×m) configuration, wherein n is less than m.

[0145] B5. The additive manufacturing system of any of the preceding clauses, wherein the heat source array comprises a plurality of lasers, each of the plurality of lasers having a mechanically adjustable position.

[0146] B6. An additive manufacturing system as described in any of the preceding clauses, wherein the heat source array includes columns of heat sources, each heat source column being controllable to apply heat at a different temperature.

[0147] B7. An additive manufacturing system as described in any of the preceding clauses, wherein the heat source array is configured to produce a heat spot pattern, wherein at least one of a heat spot diameter or a heat spot spacing of the heat spot pattern is controllable to control the size of the combined molten pool.

[0148] B8. An additive manufacturing system as described in any of the preceding clauses, wherein the heat source array comprises a plurality of lasers, each of the plurality of lasers being controllable to generate a heat spot at a different temperature.

[0149] B9. The additive manufacturing system of any of the preceding clauses, wherein the plurality of lasers are arranged in a plurality of columns, at least two of the columns having different numbers of lasers.

[0150] Clause Group C:

[0151] C1. One or more computer storage devices having stored thereon computer executable instructions for operating a heat source during additive manufacturing, the computer executable instructions, when executed by a computer, causing the computer to perform operations comprising:

[0152] applying heat to a first plurality of metal particles in the powder bed using a first heat source, the first heat source being one of a plurality of heat sources configured in an array, the first heat source producing a first molten pool;

[0153] applying heat to a second plurality of metal particles in the powder bed simultaneously using a second heat source from the plurality of heat sources in the array to produce a second molten pool, the first plurality of metal particles being separated by a distance from the second plurality of metal particles, the distance and the amount of heat from each heat source being controlled to produce a combined molten pool that is larger in size and surrounds the first molten pool and the second molten pool; and

[0154] The combined molten pools are allowed to solidify to form the object.

Claims

1. A method for additively manufacturing an object, the method comprising: applying heat to a first plurality of metal particles in the powder bed using a first heat source, the first heat source being one of a plurality of heat sources configured in an array, the first heat source producing a first molten pool (118); using a second heat source from the plurality of heat sources in the array to simultaneously apply heat to a second plurality of metal particles in the powder bed to produce a second molten pool (120), the first plurality of metal particles being separated by a distance from the second plurality of metal particles, the second molten pool (120) being proximate and parallel to the first molten pool (118), controlling the distance and the amount of heat from each heat source to produce a combined molten pool (502) that is larger in size and surrounds the first molten pool (118) and the second molten pool (120); and The combined molten pools (502) are allowed to solidify to form the object, wherein waste heat stored in the parallel molten pools allows the parallel molten pools to merge before solidification occurs.

2. The method according to claim 1 further comprises using additional heat sources in the array to generate corresponding additional molten pools, wherein the additional molten pools have corresponding changes in size relative to the combined molten pool (502), and the array is configured as an (m×m) configuration or an (n×m) configuration, wherein n is less than m.

3. The method according to claim 2, wherein: Using additional heat sources in the array to generate the combined molten pool (502) includes selectively controlling a number of heat sources in the array that apply heat to expand the combined molten pool (502) and shape the combined molten pool.

4. The method of claim 1, further comprising adjusting relative positions of the first heat source and the second heat source to adjust mechanical properties of the object formed by the combined molten pool (502).

5. The method according to claim 1 further comprises using additional heat sources in the array to generate corresponding additional molten pools, wherein the additional molten pools have corresponding changes in size relative to the combined molten pool (502), and the array is constructed in one of a non-rectangular structure or an asymmetric structure.

6. An additive manufacturing system (100), comprising: a powder bed configured to receive a coating of metallic particles; as well as A heat source array, the heat source array comprising at least a first heat source and a second heat source, the first heat source being configured to apply heat to a first plurality of adjacent metal particles in the coating to produce a first molten pool (118), the second heat source being configured to apply heat to a second plurality of adjacent metal particles in the coating to produce a second molten pool (120), the first plurality of adjacent metal particles being separated by a distance from the second plurality of adjacent metal particles, the second molten pool (120) being close to and parallel to the first molten pool (118), the distance and the amount of heat from each of the heat sources being controlled to produce a combined molten pool (502) that is larger in size and surrounds the first molten pool (118) and the second molten pool (120), and the combined molten pool (502) being allowed to solidify to form an object, wherein waste heat stored in the parallel molten pools allows the parallel molten pools to merge before solidification occurs.

7. The additive manufacturing system (100) according to claim 6, wherein: The heat source array includes a laser (310) array configured to generate a plurality of heat spots (710), each heat spot having a defined diameter and a defined pitch.

8. The additive manufacturing system (100) according to claim 6, wherein: The heat source array is configured in an m×m configuration or an n×m configuration, where n is less than m.

9. The additive manufacturing system (100) according to claim 6, wherein: The heat source array includes a plurality of lasers (310), each laser (310) of the plurality of lasers (310) having a mechanically adjustable position.

10. The additive manufacturing system (100) according to claim 6, wherein: The heat source array is configured to generate a heat spot pattern, wherein at least one of a heat spot diameter or a heat spot spacing of the heat spot pattern is controllable to control the size of the combined molten pool (502).

11. The additive manufacturing system (100) according to claim 6, wherein: The heat source array includes a plurality of lasers (310), each of which is controllable to generate a heat spot at a different temperature.

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