Additive Manufacturing Methods

Abstract

The name of the invention is additive manufacturing method. The present disclosure provides a method for forming a product using one or more lasers. In at least one aspect, the method for powder bed additive manufacturing includes defining a uniformly spaced grating path for the laser to travel at a predetermined travel rate. The grating path alternates back and forth within a strip width of less than 0.5 mm so that the power density level of the laser is at least 80% of the maximum power, and the predetermined travel rate produces a travel speed of not less than 1,000 mm / s in the scan width direction. The method includes depositing a powder layer onto a substrate and causing the laser to harden a certain amount of powder according to the defined grating path and laser power setting.

Description

Technical Field

[0001] The present disclosure provides methods of forming products using one or more lasers. Background Art

[0002] Vehicles such as aircraft contain many metal parts. To date, metal additive manufacturing has focused mainly on titanium, nickel and steel alloys. This is due to a variety of reasons: from ease of deposition to the favorable economic factors of using these alloys.

[0003] However, recent interest has turned to aluminum alloys, with a particular focus on how aluminum alloys can be used in the laser powder bed fusion (L-PBF) process. Additively manufactured aluminum enables designers to gain the benefits of additive manufacturing in terms of both performance and weight savings. However, designers are currently limited to relatively low-performance aluminum silicon casting alloys due to the difficulty in processing other traditional high-strength aluminum alloys (2XXX, 7XXX series). Currently, the leading additively manufactured aluminum alloy is Al10SiMg. It is easy to deposit, but has ordinary mechanical properties, which limits its widespread application. High-strength traditional wrought alloys are not easy to manufacture due to their high susceptibility to hardening cracks and element loss during the deposition process.

[0004] There is a need for additive manufacturing methods for high-strength alloys that can suppress residual stress cracking. Summary of the invention

[0005] The present disclosure provides methods of forming products using one or more lasers.

[0006] In at least one aspect, a method for powder bed additive manufacturing includes defining a uniformly spaced raster path for a laser to travel at a predetermined travel rate. The raster path alternates back and forth within a swath width of less than 0.5 mm so that the power density level of the laser is at least 80% of the maximum power, and the predetermined travel rate produces a travel speed of not less than 1,000 mm / s in the scan width direction. The method includes depositing a powder layer onto a substrate and causing the laser to harden a certain amount of powder according to the defined raster path and laser power settings.

[0007] In at least one aspect, a method for additive manufacturing includes depositing a layer of material onto a substrate. The method includes treating the material with a laser by moving the laser in a raster path relative to the substrate at a travel speed of not less than 1,000 mm / s in a scan width direction. The raster path has a lateral distance of about 0.1 mm to about 5 mm, a scan width distance of about 0.08 mm to about 0.2 mm, and an average hatch spacing of about 0.04 mm to about 2 mm. The laser beam has an average power of about 200 W to about 1,000 W, and a beam diameter of about 0.05 mm to about 0.2 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order that the manner in which the above-mentioned features of the present disclosure are understood in detail, a more specific description of the present disclosure briefly summarized above may be made by reference to examples, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only typical examples of the present disclosure and are therefore not to be considered as limiting the scope thereof, as the present disclosure may allow for other equally effective examples.

[0009] Figure 1 is a flow chart of an example of an aircraft production and service method according to one or more aspects.

[0010] Figure 2 is a block diagram of an example of an aircraft according to one or more aspects.

[0011] Figure 3 is a schematic perspective view of an additive manufacturing apparatus according to one or more aspects.

[0012] Figure 4 is a bottom isometric view of a portion of an example of an additive manufacturing system and an example of a part or product manufactured by the additive manufacturing system according to one or more aspects.

[0013] Figure 5 Based on one or more aspects Figure 4 A top isometric view of a portion of the additive manufacturing system shown in FIG.

[0014] Figure 6 Based on one or more aspects Figure 4 Elevation view of the additive manufacturing system shown in .

[0015] Figure 7 Based on one or more aspects Figure 4 A partially exploded view of the additive manufacturing system shown in .

[0016] Figure 8 is based on one or more aspects along Figure 7 A cross-sectional view taken along line 7-7 in FIG.

[0017] Fig. 9 Based on one or more aspects Figure 4 An example of a block diagram of an additive manufacturing system is shown in FIG.

[0018] Fig.10 is an enlarged view of one example of a pair of surface processing devices configured to process a surface of a product according to one or more aspects.

[0019] Fig.11 Illustrated are examples of a variety of shapes that a laser beam may include according to one or more aspects.

[0020] Fig.12 Multiple laser beams having various sizes are illustrated according to one or more aspects.

[0021] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one example may be beneficially incorporated in other examples without further recitation. DETAILED DESCRIPTION

[0022] The present disclosure provides a method for additive manufacturing of high-strength alloys. In one example, a method for powder bed additive manufacturing includes defining a uniformly spaced raster path within a build chamber for a laser to travel at a predetermined constant travel rate, wherein the raster path alternates back and forth within a strip width of less than 0.5 mm, such that the power setting of the laser and the associated power density level are at least 80% of the maximum power, and the predetermined constant travel rate produces a forward travel speed of not less than 1000 mm / s. The method includes depositing a powder layer within the build chamber; and according to the defined raster path and laser power setting, causing the laser to harden a certain amount of powdered metal.

[0023] The method of the present disclosure can suppress residual stress cracks by changing the hardening rate of the alloy during processing. For example, by using a narrow laser strip width, the amplitude of the oscillation of the laser travel path within the strip is reduced. Therefore, for a set travel speed, the laser head can move faster along the strip. Moving the laser head faster allows the use of increased laser power compared to conventional laser sintering processes. In addition, moving the laser faster also allows the melt pool of the previous scan pass to be completely cooled before the next line in the raster is scanned, which produces a significantly slower hardening front, which can reduce the hardening shrinkage rate (and by extension, the strain rate imposed on the liquid film at the grain boundaries in the melt). The overlapping heat input of adjacent laser weld passes (e.g., overlapping melt pools) provides uniform heat input and reduced temperature gradients across the strip of a given component, which reduces the strain caused by CTE and reduces the hardening rate, thereby providing reduced cracking of the formed component.

[0024] More specifically, referring to the accompanying drawings, Figure 1 The aircraft manufacturing and use method 100 shown and Figure 2Aspects of the disclosure are described in the context of an aircraft 102 as shown. During pre-production, method 100 may include specification and design 104 of the aircraft 102, and material procurement 106. During production, part and subassembly manufacturing 108 and system integration 110 of the aircraft 102 takes place. Thereafter, the aircraft 102 may be certified and delivered 112 and placed into service 114. While in service with a customer, the aircraft 102 is scheduled for routine maintenance and service 116 (which may also include modification, reconfiguration, refurbishment, etc.).

[0025] Each process of method 100 may be performed or executed by a system integrator, a third party, and / or an operator (e.g., a customer). For the purposes of this description, a system integrator may include, but is not limited to, any number of aircraft manufacturers and main system subcontractors; a third party may include, but is not limited to, any number of vendors, subcontractors, and suppliers; and an operator may be an airline, a leasing company, a military entity, a service organization, etc.

[0026] like Figure 2 As shown, an aircraft 202 produced by method 100 may include a fuselage 218 and an interior 222 having a plurality of systems 220. Examples of high-level systems 220 include one or more of a propulsion system 224, an electrical system 226, a hydraulic system 228, and an environmental system 230. Any number of other systems may be included. Although an aviation example is shown, the principles of the present disclosure may be applied to other industries, such as the automotive industry or other industries.

[0027] The apparatus and methods embodied herein may be employed during any one or more stages of the production and service method 100. For example, parts or subassemblies corresponding to the production process 206 may be fabricated or manufactured in a manner similar to the way parts or subassemblies are produced while the aircraft 202 is in service. Also, one or more apparatus aspects, method aspects, or a combination thereof may be utilized during the production stages 208 and 210, for example, by substantially speeding up or reducing the cost of assembling the aircraft 202. Similarly, one or more apparatus aspects, method aspects, or a combination thereof may be utilized while the aircraft 202 is in service, but not limited to, maintenance and service 116.

[0028] Laser ablation

[0029] The additive manufacturing process of the present disclosure may include operating an additive manufacturing head including a material output and a laser output. The material of the material output is an additive manufacturing material (e.g., aluminum powder) that is deposited on a surface of a part (e.g., a vehicle part). The material may be deposited on the surface of the part before, during, or after laser ablation of the surface.

[0030] Generally refer to Figure 3, the additive manufacturing device 300 has a material output unit in addition to the laser output unit. Before, during or after laser ablation, the material is deposited onto the surface 320 through the material output unit. The material output unit can be a hopper configured to gravity deposit (or pressurize) the material onto the surface 320. The material can be or include aluminum, aluminum alloy, titanium, titanium alloy, nickel, nickel alloy, stainless steel, alloy steel, cobalt alloy, plastic, polymer, polyetherimide (ultem), nylon or a combination thereof. The aluminum alloy can be or include a high-strength aluminum alloy, such as a 2XXX series, a 7XXX series or a combination thereof. The material can be in powder form, such as a fine powder.

[0031] Once deposited, the material (e.g., aluminum powder) can undergo a pretreatment laser bead, which is a low power raster on the material to be ablated (e.g., powder). The low wattage powder of the laser removes moisture adhering to the material, which reduces the likelihood of porosity development from bubbles in the ablated product material. In addition, the pretreatment preheats the area to be ablated so that when melting does occur, the temperature gradient during hardening is less than the temperature gradient without the pretreatment. Therefore, this pretreatment provides reduced cracking of the ablated product material. The laser beam average power of the laser used in the pretreatment stage can be about 50W to about 400W, such as about 100W to about 350W, such as about 200W to about 300W.

[0032] return Figure 3 , the additive manufacturing apparatus 300 includes an additive manufacturing system 304 having one or more lasers configured to emit a laser beam 344. The system 304 is configured to deliver the laser beam 344 to the surface 320. The position of the system 304 can be adjusted relative to the position of the surface 320 and the system 304. A controller (not shown) is programmed to determine operating parameters and scan the surface 320. The controller is programmed to determine operating parameters such as traverse scanning speed, width scanning speed, laser beam average power, and laser beam diameter for each scanning zone 336 of the area 330 of the surface 320. The traverse scanning speed, width scanning speed, laser beam average power, and laser beam diameter corresponding to any one of the scanning zones 336 produce a target energy density (fluence) and target irradiance of the laser beam 344. The efficiency of laser ablation depends on the irradiance (surface density of laser power) and energy density (surface density of accumulated laser energy), as well as other factors such as laser wavelength, surface material, and material to be ablated. During the movement of the laser along the scanning width direction, the laser crosses the substrate surface to form a strip. Therefore, the laser beam diameter corresponds to the width of the stripe (also called "stripe width").

[0033] The scanning zones 336 are arranged so that all regions 330 of the surface 320 can be scanned by the laser beam 344. Each scanning zone 336 has a width corresponding to the swath width 340. The controller is programmed to scan the regions 330 of the surface 320 with the laser beam 344 at a target energy density and a target irradiance, wherein each scanning zone 336 is scanned at a scanning speed corresponding to a particular one of the scanning zones 336 and across the swath width 340 corresponding to the particular one of the scanning zones 336. The laser beam 344 has a laser beam average power corresponding to the particular one of the scanning zones 336 and a laser beam diameter corresponding to the particular one of the scanning zones 336.

[0034] The laser may be scanned in a raster pattern including a scan width direction 342 and a transverse direction 346. The laser is scanned relatively quickly in the scan width direction 342 and relatively slowly in the transverse direction 346. The scanning in the scan width direction 342 is so fast that the laser beam may be considered as a laser sheet having a width of a strip width (e.g., strip width 340). However, it should be noted that the laser beam itself may not have a width that spans the strip width 340, but rather the laser travels along the strip width 340, after which the laser moves evenly spaced intervals in the transverse direction 346 to start the next strip width 340. The power of the laser sheet is substantially, if not entirely, the same as the power of the laser beam, but the irradiance (surface density of power, also referred to as power density) of the laser sheet is reduced from the irradiance of the laser beam. The irradiance is inversely proportional to the width of the laser sheet (the strip width). Thus, a smaller strip width produces a larger irradiance, while a larger strip width produces a smaller irradiance. The strip width of the method of the present disclosure can be about 0.5mm or less, such as about 0.3mm or less, such as about 0.18mm or less, such as about 0.15mm or less, such as about 0.12mm or less, such as about 0.1mm or less, such as about 0.1mm to about 5mm, such as about 0.1mm to about 2mm, such as about 0.1mm to about 0.18mm, such as about 0.2mm to about 0.15mm, such as about 0.2mm to about 0.12mm, such as about 0.5mm to about 1mm. It has been found that a narrow strip width can allow the laser to move faster along the substrate and increase the laser power to be used. These parameters can provide a reduced hatch spacing, which provides a stress reduction of the product material with reduced cracks and ablation.

[0035] The ablation efficiency of laser ablation (i.e., the efficiency of ablation) is determined by the surface density of the laser power and the surface density of the laser energy at the surface 320. The surface density of the laser power (laser power divided by the surface area receiving the power) is called the irradiance. The surface density of the laser energy (laser energy divided by the surface area receiving the energy) is called the energy density. Other factors, such as the laser wavelength, the surface material, and the material to be ablated, may also affect the ablation efficiency.

[0036] The additive manufacturing apparatus 300 is configured to adjust operating parameters for each scanning zone 336 so that each scanning zone 336 is scanned at the same target energy density and the same target irradiance. For each scanning zone 336, scanning at the same energy density and irradiance provides the same ablation efficiency. The energy density and irradiance are primarily determined by the strip width. If the strip width varies (while the scanning speed remains constant), the energy density and / or irradiance vary because the laser dwell time at the surface is adjusted.

[0037] Scanning zone 336 is arranged within region 330 of surface 320. Surface 320 is the surface of workpiece 324 to be ablated by laser ablation by device 300. Typically, workpiece 324 includes a hard and / or elastic material, such as metal (such as high-strength aluminum) and / or ceramic. Surface 320 can be a substantially metal and / or ceramic surface.

[0038] Workpiece 324 can be a part, such as a blade of a wind turbine. In at least one aspect, workpiece 324 is a vehicle part. A vehicle part is any suitable part of a vehicle, such as a structural part of an aircraft, an automobile, etc., such as a panel or a joint. Examples of vehicle parts include wings (such as rotor blades), auxiliary power units, noses of aircraft, fuel tanks, tail cones, panels, coated lap joints between two or more panels, wing to fuselage assemblies, structural aircraft composites, fuselage body joints, wing rib to skin joints, and / or other internal parts.

[0039] The scanning zones 336 are each a different zone of the region 330 (the scanning zones 336 may partially overlap). Each scanning zone 336 is a small portion of the region 330 and is substantially an area swept by the laser beam 344 in the scan width direction 342. The laser beam 344 is directed by the additive manufacturing system 304 to move substantially continuously and sequentially between the scanning zones 336. Thus, one scanning zone 336 is completed before another scanning zone 336 is started. The various zones of the scanning zones 336 are distributed along the transverse direction 346.

[0040] In a raster manner, the laser travels a lateral distance and scans a width distance corresponding to a strip width 340, wherein each strip width 340 along which the laser travels is separated from the next strip width by a uniform spacing interval corresponding to the lateral distance. Therefore, due to the narrow scan width of the disclosed method, the lateral distance can also be small, which provides uniform heat input and reduced temperature gradients across the strips of a given component, which reduces strain and hardening rates. The lateral distance of the disclosed method can be about 5 mm or less, such as about 2 mm or less, such as about 0.18 mm or less, such as about 0.15 mm or less, such as about 0.12 mm or less, such as about 0.1 mm or less, such as about 0.1 mm to about 5 mm, such as about 0.1 mm to about 2 mm, such as about 0.1 mm to about 0.18 mm, such as about 0.2 mm to about 0.15 mm, such as about 0.2 mm to about 0.12 mm, such as about 0.5 mm to about 1 mm. The scan width distance of the method of the present disclosure can be about 0.3 mm or less, such as about 0.25 mm or less, such as about 0.2 mm or less, such as about 0.15 mm or less, such as about 0.1 mm or less, such as about 0.08 mm or less, such as about 0.05 mm to about 0.3 mm, such as about 0.08 mm to about 0.25 mm, such as about 0.1 mm to about 0.25 mm, such as about 0.1 mm to about 0.2 mm, such as about 0.15 mm to about 0.2 mm, such as about 0.15 mm to about 0.18 mm. The lateral distance and the scan width distance together provide a scan density for a specific surface area, so that the method of the present disclosure is performed at a scan density. For example, the scan density can be high, such as about 5,000 laser welds / m 2 Up to about 25,000 laser welds / m 2 , such as about 8,750 laser welds / m 2 Up to about 18,750 laser weld passes / m 2 It has been found that high scan density can provide uniform heat input and reduced temperature gradients across a strip of a given part, which reduces strain and hardening rates.

[0041] In addition, the small lateral distance of the present disclosure provides a small hatch spacing. As used herein, the term "hatch spacing" may refer to a uniform spacing interval or distance between two adjacent scan width weld passes. The average value of the hatch spacing for a given scan area (e.g., number of weld passes / m) may be 2 ) is referred to as the "average hatch spacing". The method of the present disclosure can be performed with a low average hatch spacing. For example, the average hatch spacing can be about 0.04 mm to about 2 mm, such as about 0.07 mm to about 0.15 mm, such as about 0.09 mm to about 0.13 mm, such as about 0.11 mm.

[0042] The laser and laser beam 344 have several characteristics that are adjustable to control the irradiance and energy density in each scanning zone 336. The laser of the present disclosure may have a constant output (e.g., the output is not pulsed). The laser beam 344 has a laser beam average power and a laser beam spot area (the area when the laser beam 344 hits the surface 320). The laser beam 344 is swept across the scanning zone 336 in the scanning width direction 342 at a raster path scanning speed (which may be different for different scanning zones 336). The laser beam 344 is swept between the scanning zones 336 in the transverse direction 346 at a transverse scanning speed (which may be different for different scanning zones 336). The additive manufacturing device 300 controls or adjusts each of the characteristics (transverse scanning speed, raster path scanning speed, laser beam average power, and laser beam spot area) independently for each scanning zone 336. For each scanning zone 336, some (but not all) characteristics may be the same. In at least one aspect, the method of the present disclosure includes sweeping the laser (and laser beam) in the scan width direction at a raster path scanning speed of not less than 1,000 mm / s, such as about 1,100 mm / s to about 3,000 mm / s, such as about 1,300 mm / s to about 2,800 mm / s, such as about 1,500 mm / s to about 2,500 mm / s, such as about 1,700 mm / s to about 2,200 mm / s. In at least one aspect, the method of the present disclosure includes a laser (and laser beam) traveling along a uniformly spaced raster path at a predetermined travel rate, wherein the raster path alternates back and forth within a strip width of less than 0.5 mm, so that the power density level of the laser is at least 80% of the maximum power, and the predetermined travel rate results in a travel speed of not less than 1,000 mm / s in the scan width direction. The method of the present disclosure includes scanning the laser (and laser beam) at a transverse scanning speed of not less than 1000 mm / s, such as about 1,100 mm / s to about 3000 mm / s, such as about 1300 mm / s to about 2,800 mm / s, such as about 1,500 mm / s to about 2,500 mm / s, such as about 1,700 mm / s to about 2,200 mm / s. In at least one aspect, the laser (and laser beam) moves (sweeps) at a raster path scanning speed substantially the same as the transverse scanning speed in the scanning width direction. The average power of the laser beam of the laser is about 200 W to about 1,000 W, such as about 300 W to about 600 W, such as about 400 W to about 500 W, such as about 400 W to about 450 W. By using a narrow strip width of the laser, the oscillation amplitude of the laser travel path within the strip is reduced. Therefore, for a set travel speed, the laser head can move faster along the strip. Moving the laser head faster allows the use of increased laser power (while achieving reduced thermal gradients) compared to conventional laser sintering processes.In at least one aspect, the power density level of the laser is at least 80%, such as at least about 85%, at least about 90%, such as at least about 95%, such as at least about 99%, such as about 100% of the maximum power of the laser.

[0043] For the additive manufacturing device 300, the irradiance is a function of the average power of the laser beam and the laser beam spot area (determined by the laser beam diameter). As used herein, the target irradiance refers to the peak irradiance, that is, the laser beam peak power divided by the surface covered by the laser beam 344. Typically, the laser beam peak power is a function of the average power of the laser beam. The target irradiance can be increased by increasing the average power of the laser beam and / or reducing the laser beam spot area (e.g., reducing the beam diameter). If the average power of the laser beam is reduced, the target irradiance can be maintained by compensating for the decrease (proportional) in the laser beam spot area. In at least one aspect, the beam diameter of the laser beam of the present disclosure is about 0.05 mm to about 0.2 mm, such as about 0.05 mm to about 0.18 mm, such as about 0.08 mm to about 0.15 mm, such as about 0.1 mm to about 0.14 mm, such as about 0.13 mm.

[0044] For the additive manufacturing apparatus 300, the energy density is a function of the average power of the laser beam, the strip width 340, and the lateral scanning speed. As used herein, the target energy density refers to the energy density of the laser beam 344 as it scans across the area 330. The target energy density can be calculated according to the following equation:

[0045] F = P Sw x Ts (Equation 1)

[0046] Where F is the target energy density, P is the average power of the laser beam, S w The strip width is 340, T s is the transverse scanning speed. The target energy density can be reduced by reducing the average power of the laser beam, increasing the stripe width 340 and / or increasing the transverse scanning speed. If the stripe width 340 is reduced, the target energy density can be maintained by a compensating increase (inversely proportional) in the transverse scanning speed.

[0047] The raster path scan speed, the stripe width 340, and the lateral scan speed are implemented by the additive manufacturing system 304. The additive manufacturing system 304 has one or more lasers configured to deliver a laser beam 344 to the surface 320 in the area 330 (e.g., in the scan zone 336). The additive manufacturing system 304 is configured to scan the laser beam 344 along the scan line 332 in the stripe width direction 344 at a rate of the raster path scan speed for each scan zone 336 by a scan width distance corresponding to the stripe width 340. The scan line 332 does not have to be a straight line, but can be an arc, a curve, and / or a segmented line. Typically, the raster path scan speed is much faster than the lateral scan speed, so that when the laser beam is scanned at the raster path scan speed, the laser beam 344 can be processed or viewed as a laser sheet. For example, the raster path scan speed can be greater than 1,000 times the lateral scan speed. The additive manufacturing system 304 is configured to optically scan the laser beam 344 because the optical scanning laser beam 344 is generally much faster than the mechanical scanning laser beam 344. The additive manufacturing system 304 includes a laser scanning device for high-speed scanning, such as a mirror galvanometer or a polygon mirror. The raster path scanning speed and the lateral scanning speed can be independently varied.

[0048] The selection of the nominal stripe width, the target energy density, and the target irradiance can provide sufficient information to determine the nominal laser beam average power, the nominal lateral scanning speed, and / or the nominal laser beam spot area. Optionally, the nominal parameters can define the target energy density and the target irradiance. The selection of the nominal stripe width, the target energy density, and / or the target irradiance can be used to tune the additive manufacturing apparatus 300 to manufacture different materials that may be present on various workpieces 324.

[0049] The scan area 336 may be determined by inspecting or modeling the surface 320. The scan area 336 may be determined by dividing the area 330 into a series of zones, where each zone is described by only one strip width 340 for that zone (each zone of the scan area 336). The scan area 336 may be determined by other devices and / or an operator and then provided to the controller 310 to follow the pattern of the provided scan area 336. Thus, the controller 310 may be dedicated to scanning operations and may not need to determine the scan area 136.

[0050] Scan area 336 may be determined by identifying area 330 of surface 320 and dividing area 330 into scan area 336. A virtual model of surface 320 and / or workpiece 324 may facilitate accurate determination of the location of area 330 and / or scan area 336. The virtual model may be a two-dimensional (2D) or three-dimensional (3D) model and may be an electronic description of the surface, boundaries, and / or points of surface 320 and / or workpiece 324. For example, the virtual model may be a CAD (computer-aided design) model, a boundary representation, and / or a surface tessellation.

[0051] Each of the scan zones 336 may have a different strip width 340 (at least one strip width 340 is different). The strip width 340 of each of the scan zones 336 may be determined by the size of the scan zone 336 and / or the region 330 determined based on the virtual model of the surface 320. The virtual model of the surface 320 and / or the workpiece 324 may help to accurately determine the strip width 340 of each of the scan zones 336.

[0052] Laser ablation of the surface 320 begins at one of the scan zones 336 and continues at each of the other scan zones 336. The first of the scan zones 336 is selected based on proximity to an edge of the region 330 and / or proximity to the other scan zones 336. The ordering of the scan zones 336 allows for efficient laser ablation of the region 330 of the surface 320. For example, arranging the first and subsequent scan zones 336 of the scan zones 336 so that completion of the first of the scan zones 336 (and subsequent scan zones 336) is at or near the next one of the scan zones 336 allows the additive manufacturing device 300 to scan the region 330 with little (or no) time devoted to moving between the scan zones 336.

[0053] As described above, the controller is programmed to determine the lateral scan speed, the laser beam average power, and the laser beam spot area by setting the lateral scan speed equal to the maximum lateral scan speed and determining a scan speed proportional to the stripe width for each of the scan zones 336 when the stripe width 340 is less than a first critical stripe width and greater than or equal to a second critical stripe width. The first critical stripe width is greater than the second critical stripe width.

[0054] The additive manufacturing apparatus 300 has a maximum lateral scan speed. For example, the lateral scan speed may be limited by reliable operation of mechanical parts of the translational additive manufacturing system 304 and / or the workpiece 324. For a scan zone 336 where the strip width 340 is less than the first critical strip width, a target energy density may be achieved by selecting a lateral scan speed greater than the maximum lateral scan speed. A smaller strip width 340 may require a larger lateral scan speed to produce the same target energy density. If the strip width 340 is small enough (i.e., less than the first critical strip width) to imply that the lateral scan speed is greater than the maximum lateral scan speed, the lateral scan speed may be set to the maximum lateral scan speed and the laser beam average power may be reduced based on the maximum lateral scan speed and the strip width 340 less than the first critical strip width to achieve the target energy density. The laser beam average power may be reduced in proportion to the strip width 340 (according to Equation 1) to achieve the target energy density.

[0055] The scanning zones 336 are continuous with one another, i.e., adjacent scanning zones 336 touch, partially overlap, and / or are connected to one another. With continuous scanning zones 336, the laser beam 344 can be scanned in a continuous motion from one of the scanning zones 336 to the next of the scanning zones 336 without translating the surface 320 relative to the additive manufacturing system 304 between the scanning zones 336. Therefore, scanning the continuous scanning zones 336 does not require delays between the scanning zones 336 and the resulting ineffective ablation of the region 330. The continuous scanning zones 336 provide a continuous region 330, which can be characterized as having a single border to encompass all of the scanning zones 336. The continuous region 330 may have no internal gaps or voids (regions not included in one of the scanning zones 336).

[0056] The scanning interval 348 separating the additive manufacturing system 304 from the region 330 of the surface 320 is substantially constant in each of the scanning zones 336. The substantially constant (or uniform) scanning interval 348 within one of the scanning zones 336 can establish a substantially constant (or uniform) laser beam spot area within one of the scanning zones 336. For each scanning zone 336, the scanning interval 348 can be substantially constant (or uniform), although different scanning zones 336 can be scanned with different scanning interval 348 values. The scanning interval 348 (and thus the possible laser beam spot area) can be adjusted independently for each of the scanning zones 336.

[0057] The scan interval 348 may not vary between scan zones 336, which may facilitate transitions between scan zones 336 without requiring translation of the surface 320 relative to the additive manufacturing system 304. A substantially constant (or uniform) scan interval 348 for all scan zones 336 may not preclude adjustment of the laser beam spot area (e.g., diameter). The laser beam spot area may be varied as needed or desired by adjusting the focal distance of the surface 320 with respect to the additive manufacturing system 304.

[0058] Scanning each scan area 336 at a perpendicular (orthogonal) angle of incidence can provide effective ablation in the scan area 336. When the laser beam 344 is oriented perpendicular to the surface 320, the laser beam 344 can have a higher (or maximum) target irradiance. If the laser beam 344 hits the surface 320 at an angle significantly different from the perpendicular (perpendicular), the spot of the laser beam 344 may be deformed and become larger (thereby reducing the target irradiance). As used herein, the perpendicular angle of incidence is approximately perpendicular to the surface 320 (at about 90°, such as about 80° to about 100°, such as about 85° to about 95°).

[0059] By appropriately selecting the target energy density and the target irradiance, the region 330 can be effectively ablated without significant over-ablation, significant under-ablation, or inadvertent scanning of areas outside of the region 330. The variation in swath width 340 between scanned regions 336 is compensated for relative to conventional laser ablation to maintain the target energy density and target irradiance for all scanned regions 336.

[0060] Operating parameters (e.g., lateral scanning speed, laser beam average power, and laser beam spot area) may be independently determined for one of the scan zones 336 based on the swath width 340, the target energy density, and the target irradiance of the one of the scan zones 336. The operating parameters may be determined based on the target energy density and the target irradiance.

[0061] The scan zones 336 can be scanned sequentially such that the scan zones 336 are arranged within the region 330 of the surface 320 and are ordered. Sequential scanning includes scanning each of the scan zones 336 in turn in a sequential order. Sequential scanning can reduce the time to move the additive manufacturing system 304, the laser beam 344, and / or the workpiece 324 between the scan zones 336, and thus can increase efficiency relative to out-of-sequential scanning.

[0062] Scanning the surface 320 sequentially may begin at one of the scan zones 336 and continue at each of the other scan zones 336. The first of the scan zones 336 is selected based on proximity to an edge of the region 330 and / or proximity to the other scan zones 336. The sequencing of the scan zones 336 allows for efficient laser ablation of the region 330 of the surface 320. For example, arranging the first and subsequent scan zones 336 of the scan zones 336 so that completion of the first of the scan zones 336 (and subsequent scan zones 336) is at or near the next one of the scan zones 336 allows the additive manufacturing device 300 to scan the region 330 with little (or no) time devoted to moving between the scan zones 336.

[0063] When the strip width 340 of at least one of the scanning areas 336 is different from the strip width 340 of another of the scanning areas 336, at least one of the lateral scanning speed, the laser beam average power, or the laser beam spot area of ​​the laser beam 344 of at least one of the scanning areas 336 is different from at least one of the lateral scanning speed, the laser beam average power, or the laser beam spot area of ​​the laser beam 344 of another of the scanning areas 336.

[0064] To maintain target energy density and target irradiance across all scan zones 336 , one or more changes in lateral scan speed, laser beam average power, and / or laser beam spot area may be used to compensate for changes in swath width 340 in scan zone 336 .

[0065] The lateral scan speed is the laser beam average power divided by the product of the stripe width 340 and the target energy density. If the initial laser beam average power and stripe width 340 (for at least one of the scan zones 336) are suitable for setting the lateral scan speed (e.g., the calculated lateral scan speed is within operational limits), the lateral scan speed is the product of the stripe width 340 and the target energy density for at least one of the scan zones 336.

[0066] The laser beam 344 has an initial laser beam average power. The scanning area 336 includes adapted scanning areas. Determining the transverse scanning speed, the laser beam average power, and the laser beam spot area of ​​each of the scanning areas 336 includes determining that the projected transverse scanning speed of the adapted scanning area is greater than the maximum transverse scanning speed. The projected transverse scanning speed of the adapted scanning area is the initial laser beam average power divided by the product of the strip width 340 of the adapted scanning area and the target energy density. The method of the present disclosure may include determining the adapted laser beam average power, which is the product of the target energy density, the strip width 340 of the adapted scanning area, and the maximum transverse scanning speed.

[0067] The additive manufacturing device 300 may have a maximum lateral scanning speed. For example, the lateral scanning speed may be limited by reliable operation of mechanical parts (i.e., the laser positioning device 306) that translate the additive manufacturing system 304 and / or the workpiece 324. For a scanning zone 336 having a strip width 340 less than the first critical strip width, a target energy density may be achieved by selecting a planned lateral scanning speed greater than the maximum lateral scanning speed. Such a scanning zone 336 may be referred to as an adapted scanning zone because adaptation of operating parameters is required to achieve the target energy density and not exceed the maximum lateral scanning speed. For an adapted scanning zone, the planned lateral scanning speed may be set to the maximum lateral scanning speed, and the adapted laser beam average power may be reduced from the initial laser beam average power to achieve the target energy density based on the maximum lateral scanning speed and the strip width 340 of the adapted scanning zone. The adapted laser beam average power may be set according to Equation 1, i.e., the adapted laser beam average power is the product of the target energy density, the strip width 340 of the adapted scanning zone, and the maximum lateral scanning speed.

[0068] The area 330 of the scanned surface 320 includes a stripe width 340 across the adapted scan area at a maximum transverse scan speed while the laser beam 344 has an adapted laser beam average power and a laser beam spot area of ​​the adapted scan area.

[0069] Determining the lateral scanning speed, laser beam average power, and laser beam spot area for each of the scanning zones 336 includes determining that the planned laser pulse repetition rate for the adapted scanning zone is less than a minimum laser pulse repetition rate. The planned laser pulse repetition rate for the adapted scanning zone is the product of the adapted laser beam average power divided by the target irradiance and the laser beam spot area for the adapted scanning zone.

[0070] Using the same target energy density and target irradiance for each scan zone 336 promotes uniform ablation across region 330 .

[0071] The selection of the nominal stripe width, the target energy density, and the target irradiance can provide sufficient information to determine the nominal laser beam average power, the nominal lateral scanning speed, and / or the nominal laser beam spot area. Optionally, the nominal parameters can define the target energy density and the target irradiance. The selection of the nominal stripe width, the target energy density, and / or the target irradiance can be used to tune the additive manufacturing apparatus 300 to ablate different materials (of the surface 320) that may be present on various workpieces 324.

[0072] The method of the present disclosure includes determining a maximum swath width, which is the maximum average power of the laser beam 344 divided by the product of the target energy density and the maximum lateral scan speed. The maximum average power of the laser beam 344 can be limited by the operating limitations of the laser 302. The maximum lateral scan speed can be limited by the mechanical limitations of the additive manufacturing device 300. The determined maximum swath width can be used to qualify the region 330 for ablation potential, thereby segmenting the region 330 into separate sub-regions that do not have a swath width 340 greater than or equal to the maximum swath width, and / or dividing the region 330 into scan zones 336 that each have a swath width 340 less than or equal to the maximum swath width.

[0073] Determining operating parameters (e.g., lateral scan speed, laser beam average power, and laser beam spot area) may be performed during scanning of the scan area 336. Determining operating parameters for individual zones in the scan area 336 is performed prior to scanning the individual zones in the scan area 336. Determining operating parameters for one of the scan areas 336 is merely a prerequisite to scanning the one of the scan areas 336. Operating parameters may be determined for one of the scan areas 336 once (e.g., just prior to beginning scanning of the individual zones in the scan area 336 and / or as the individual zones in the scan area 336 are received and / or determined). Determining operating parameters at least partially concurrently with scanning allows for dynamically changing operating parameters and / or the scan area 336 during scanning. Additionally or alternatively, determining operating parameters at least partially concurrently with scanning allows for computational overhead time required to determine operating parameters to overlap with movement of the additive manufacturing system 304, the laser beam 344, and / or the workpiece 324 during scanning, thereby increasing operational efficiency.

[0074] The raster scan speed may be determined based on the amount and / or type of material to be ablated, the absorbance of the material to be ablated, and the laser wavelength. A slower raster scan speed may deposit more energy into a small area (i.e., an area of ​​the size of the laser beam spot area) of the surface 320 in a shorter time than a faster raster scan speed. A faster raster scan speed may be beneficial in reducing thermal effects on the material below the surface 320 as the laser beam 344 ablates the material above. A faster raster scan speed (relative to a slower raster scan speed) may allow vapor and / or particulates (e.g., smoke) to dissipate sufficiently to reduce optical interference with the laser beam 344. Typically, the raster scan speed is fast enough to process the scanned laser beam 344 into a laser sheet. For each scan area 336, the raster scan speed may be greater than (or equal to) the product of the band width 340 and the lateral scan speed divided by the effective average diameter of the laser beam spot area.

[0075] The raster scan speed may be sufficiently large that the entirety of each of the scan areas 336 is scanned by the laser beam 344 before the laser beam 344 moves a distance of the effective average diameter of the laser beam spot area in the transverse direction 346 at the transverse scan speed. Scanning at such a raster scan speed provides uniform coverage of the scan areas 336 and the region 330. The effective average diameter of the laser beam spot area is the diameter of a circle having the same area as the laser beam spot area. The laser beam spot area may or may not have a circular profile.

[0076] The raster scan speed is set to suit the maximum swath width and maximum lateral scan speed that can be achieved for a given apparatus, such as additive manufacturing apparatus 300. Such a raster scan speed can be used for each scan zone 336. Thus, there is no need to change the raster scan speed between scan zones 336 to maintain a target energy density or target irradiance.

[0077] The illustrated additive manufacturing apparatus and method and the presentation of other examples of additive manufacturing apparatus and methods herein are not intended to limit the present disclosure in any way. Rather, the illustrated and described additive manufacturing apparatus and methods are intended to illustrate aspects of the present disclosure. The additive manufacturing apparatus 300 can include any type of additive manufacturing apparatus, and all such possibilities are intended to be within the spirit and scope of the present disclosure.

[0078] Hardware for executing the method

[0079] Now refer to Figure 4-12 , illustrates an example of an additive manufacturing system 304, and is configured to form a part or product 404 (see Figure 4 )(which can be Figure 3 The additive manufacturing system 304 is configured to produce a wide variety of products 404 having different shapes and sizes and various levels of complexity. The products 404 can be made of a variety of materials, including metals, aluminum, aluminum alloys, titanium, titanium alloys, nickel, nickel alloys, stainless steel, alloy steels, cobalt alloys, plastics, polymers, polyetherimide, nylon, or combinations thereof.

[0080] The additive manufacturing system 304 according to one or more aspects of the present disclosure can include a variety of additive manufacturing equipment. In the illustrated system, the system 304 includes a laser additive manufacturing device. Other examples of the system of the present disclosure can incorporate optional additive manufacturing equipment, such as, for example, fused deposition modeling (FDM), multi-jet modeling (MJM), 3D printing, rapid prototyping, direct digital manufacturing, layered manufacturing, and additive manufacturing equipment.

[0081] The system 304 may include two surface processing devices 412 for processing two surfaces 416, 420 of the product 404 formed by the additive manufacturing head 408. The surfaces 416, 420 may be, for example, inner and outer surfaces, respectively. The system 304 may also be configured to include a single surface processing device 412 for processing a single surface of the product formed by the additive manufacturing head 408. Furthermore, the system 400 may include more than two surface processing devices 412 for processing any number of surfaces 416, 420 of the product 404 formed by the additive manufacturing head 408. In the illustrated system 304, the two surface processing devices 412 are substantially similar in structure and function. In other examples of the system 304, the system may include two or more surface processing devices 412, and such devices may differ in structure and function. The description and related drawings herein include two similar surface processing devices 412 having similar structure and function.

[0082] The surface processing device 412 can be configured to smooth the surface of the product formed by the additive manufacturing head 408. In other words, the surface processing device 412 can be configured to reduce the roughness of the surface of the product formed by the additive manufacturing head 408. The surface processing device 412 is movably connected to the additive manufacturing head 408. The surface processing device 412 can also be rotatably connected to the additive manufacturing head 408. The surface processing device 412 can be connected to the additive manufacturing head 408 in a variety of ways. The additive manufacturing system 304 also includes a housing 424 that is rotatably connected to the additive manufacturing head 408. The surface processing device 412 is connected to the housing 424. The housing 424 is configured to rotate about a virtual longitudinal center axis 428 that extends longitudinally and is centered through the additive manufacturing head 408 ( Figure 6 ). For example, Fig. 9 As shown in , the system 304 may include a mechanism 426 for rotatably positioning the housing 424 relative to the additive manufacturing head 408. In one aspect, the mechanism 426 may be a servo motor connected to the housing 424. Referring again to Figure 3 , the housing 424 can be rotatably connected to the additive manufacturing head via, for example, a ball bearing 440 between the additive manufacturing head 408 and the housing 424. In one example, a mechanism 426 can be connected to the housing 424 to rotatably position the housing 426 relative to the manufacturing head 408.

[0083] See for example Figure 4 and Figure 6, the surface-processing device 412 has a trailing orientation relative to the additive manufacturing head 408 as the head 408 moves relative to the product 404 being formed. The mechanism 426 rotatably positions the housing 424 relative to the additive manufacturing head 408 so that the surface-processing device 412 is in the trailing orientation relative to the additive manufacturing head 408. The surface-processing device 412 processes the product in situ while the product is being formed by the additive manufacturing head 408.

[0084] exist Figure 4-12 In the system 400 illustrated in FIG. 4 , the surface processing device 412 is a laser emitting device 412 ( Fig.10 ). For example, in Figure 4 The system 400 illustrated in FIG. 4 further includes a support member 448, a laser energy source 452 ( Fig. 9 ) and a laser delivery device 456 including a first end 460 optically connected to the laser energy source 452 and a second end 464 connected to the support member 448. According to one aspect of the present disclosure, the laser emitting device 450 can be the second end 464 of the laser delivery device 456. In one example, the second end 464 of the laser delivery device 456 is configured in a generally polygonal shape to emit a laser beam 444 having a generally polygonal cross-section.

[0085] In one example, the second end 464 of the laser delivery device 456 is connected to a polygonal-shaped laser emitting device 450 to emit a laser beam 444 having a substantially polygonal cross-section. In one variation, the shape of the laser emitting device 450 can be rectangular to emit a laser beam 444 having a substantially rectangular cross-section. A rectangular shape includes a square shape. In some aspects of the system 400, for example, when the laser emitting device 450 is rectangular in shape, when the laser beam strikes the surface being processed, the laser beam 444 is substantially parallel to the entire dimension H of the laser beam 444 (see, for example, Fig.11 and Fig.12 ) applies a constant amount of energy to the surface of the product. The above configuration of the laser beam ensures that the surface of the product being struck by the laser beam is uniformly processed (e.g., uniformly smoothed) along the entire dimension H of the laser beam. Some examples of the shape of the laser beam 444 that enables uniform processing of the surface of the product along the entire dimension H of the laser beam striking the surface being processed include, but are not limited to, a square, a rectangle, or any other shape having an equal dimension W along its entire dimension H.

[0086] See for example Fig.11In other examples of the system, the laser emitting device 450 is configured to emit a laser beam 444 having a generally arcuate peripheral shape. In further examples of the system, the laser emitting device 450 is configured to emit a laser beam 444 having a generally circular shape. When the system is configured to emit a laser beam 444 having a generally arcuate peripheral shape, such an arcuate peripheral shape can be any shape having at least a partial arcuate circumference. Some examples of arcuate peripheral shapes include, but are not limited to, a circular, semicircular, hemi-circular, elliptical, or uneven shape. It should be understood that the laser emitting device 450 is capable of emitting a laser beam 444 having any shape (see Fig.11 ).

[0087] Refer to Fig. 9 , the laser delivery device 456 is optically connected to the laser source 452 and the laser emitting device 450. Figure 4-10 In the system illustrated in FIG. 4 , the laser delivery device 456 can be a fiber optic cable 456. For example, as Figure 4 As shown in , the system 304 includes two laser delivery devices 456. The additive manufacturing system 304 may include any number of laser delivery devices 456 to communicate the laser beam (one or more) 444 from the laser energy source 452 to the laser emitting device 450. In other examples, the laser delivery device 456 may be other devices configured to optically communicate the laser beam 444 from the laser source 452 to the surface of the product formed by the additive manufacturing head 408. Some examples include, but are not limited to, mirrors, other light and energy reflecting members, light guides, etc. The laser emitting device 450 is configured to be spaced apart from the surface of the product formed by the additive manufacturing head 408. The additive manufacturing system 304 further includes a guide member 468, which is configured to engage the product formed by the additive manufacturing head 408 to orient the surface processing device 412 relative to the product. The guide member 468 spaces the surface processing device 412 a certain distance from the surface of the product. In the illustrated system 304, the guide member 468 is a guide roller 468. Although the wheels of the guide member 468 are shown engaging a surface 420 perpendicular to the machining surface 416, it should be understood that the wheels can be arranged so that the wheels engage the machining surface, such as the machining surface 416, if, for example, the additive manufacturing system 304 is moved in a raster during use. The wheels can also be balls in a ball joint to provide easy steering of the additive manufacturing system 304 during the raster process. In other examples of the system, the guide member 468 can be other types of guide members, such as, for example, a surface tracking shoe that engages and slides against the product surface, or any other type of guide member.

[0088] The additive manufacturing head 408 is configured to form a product from multiple layers L (see, e.g. Figure 4 and 10 ). The surface processing device 412 is configured to process the product formed by the additive manufacturing head 408 in various ways. In one aspect, the surface processing device 412 is configured to process one of the plurality of layers L (see, e.g. Fig.10 ). In another aspect, the surface processing device 412 is configured to process two or more of the plurality of layers L simultaneously. The surface processing device 412 can be configured to process many layers L simultaneously. Fig.12 , various sizes of rectangular cross-sections of the laser beam 444 are shown to illustrate the ability to process many layers L of a product formed by the additive manufacturing head 408. The laser beam 444 of any shape may have a variety of different sizes to process various numbers of layers of a product.

[0089] As described above, the surface processing device 412 is configured to move relative to the additive manufacturing head 408. Figure 6 , the surface processing device 412 is configured to move between a first (or active) position and a second (or idle) position relative to the additive manufacturing head 408, wherein the surface processing device 412 is capable of processing a product formed by the additive manufacturing head 408 in the first position and the surface processing device 412 is unable to process the product in the second position. In the illustrated system 400, the surface processing device 412 is rotatably connected to the housing 424, and the surface processing device 412 rotates between the first position and the second position. Figure 6 and other references Figure 4 , 5 , 7 and 8, the system 400 includes a shaft 469 having a virtual longitudinal center axis 470. The surface processing device 412 is configured to rotate about the shaft 469 and the associated longitudinal center axis 470 between a first position and a second position. Optionally, the surface processing device 412 can be connected to the additive manufacturing head 408 using any number of different methods and can be moved between the first position and the second position in a variety of different ways.

[0090] Continue to refer to Figure 4-8 , the additive manufacturing system 304 also includes a connecting member 446 and a support member 448. The connecting member 446 is connected to the housing 424 and the support member 448 and between the housing 424 and the support member 448, and the support member 448 supports the surface processing device 412. The support member 448 is configured to be relative to the connecting member 446 around the virtual longitudinal center axis 447 ( Figure 7) rotates. The additive manufacturing system 304 also includes a base 453 that defines a first hole 454 for receiving a connecting member 446, a second hole 455 that is substantially orthogonal to the first hole 454, and a pair of grooves or channels 457 defined in opposing surfaces of the base for receiving respective support members 448. A snap ring 458 connects the base 453 to the connecting member 446. The end of the support member 448 includes a countersunk hole 459 therein. The additive manufacturing system 304 also includes a mechanism 451 for adjusting the force applied to the product surface by the guide member 468. The guide member 468 is preloaded on the surface of the product to maintain a constant spacing of the surface processing device 412 relative to the product surface. In one example, the mechanism 451 for adjusting the preload includes a biasing member 461, such as a coil spring, positioned within the countersunk hole 459, and a fastener 462 extending through the biasing member 461 and the countersunk hole 459. The fastener 462 is screwed into the second hole 455 of the base 453. The connecting member 446 defines an opening or slot 463 therein to allow the base 453 to rotate relative to the connecting member 446 about the axis 447. Therefore, the base 453, the biasing member 461, the fastener 462, the support member 448 and the surface processing device 412 rotate as a whole relative to the connecting member 446 about the axis 447. The fastener 462 can be tightened or loosened to adjust the force on the guide members 468 and their preload on the surfaces 416, 420 of the product 404 by compressing the spring 461 or by allowing the spring to relax, respectively. The opening or slot 463 can be defined as a portion of the way through the connecting member 446, or can be defined as the entire way through the connecting member 446. Defining an opening or slot 463 either partially through or completely through the connecting member 446 may provide clearance between the fastener 462 and the connecting member 446 and facilitate rotation of the fastener 462 relative to the connecting member 446 .

[0091] In one aspect, the surface processing device 412 is configured to rotate about at least one axis. The at least one axis may be any one or more of the axes 428, 447, 470 (see, Figure 6-8 ). In another aspect, the surface processing device 412 is configured to rotate about at least two axes. The at least two axes may be any two or more of the axes 428, 447, 470 (see Figure 6-8 In a further aspect, the surface processing device 412 is configured to rotate about three axes. The three axes include all three axes 428, 447, 470 (see Figure 6-8 ).

[0092] Now refer to Figure 4-10, the additive manufacturing system 304 is configured to include multiple surface processing devices 412, as indicated above. In one aspect of the system 304, the surface processing device 412 includes a first surface processing device 412 and a second surface processing device 412 spaced apart from the first surface processing device 412. For example, Figure 5 As shown in FIG. 4 , a space 472 is provided between the first and second surface processing devices 412. The first surface processing device 412 and the second surface processing device 412 are in a trailing orientation relative to the additive manufacturing head 408. Therefore, the product 404 (e.g., Fig.10 ) is positioned in a space 472 between the first and second surface-processing devices 412. In one aspect, the portion of the product positioned in the space 472 is at least one layer L of the product 404. In another aspect, the portion of the product positioned in the space 472 is simultaneously at least two layers L of the product. In yet another aspect, the portion of the product positioned in the space 472 is simultaneously multiple layers L of the product.

[0093] Continue to refer to Figure 4-10 , the additive manufacturing system 304 includes a guide member 468 as described above. The guide member 468 can be a first guide member 468, and the additive manufacturing system 304 can further include a second guide member 468 opposite the first guide member 468. The first guide member 468 and the second guide member 468 are configured to engage the product formed by the additive manufacturing head 408 to provide a spacing of the first surface processing device 412 and the second surface processing device 412 relative to the product. The first guide member 468 is configured to engage the outer surface 420 of the product 404, and the second guide member 468 is configured to engage the inner surface 416 of the product 404. In the illustrated system 400, the first guide member 468 and the second guide member 468 are guide rollers 468. In other examples, the first guide member 468 and the second guide member 468 can be any type of guide member, such as, for example, a surface tracking guide plate that engages and slides against a surface of the product. The first surface processing device 412 is configured to process a first surface of a product formed by the additive manufacturing head 408, and the second surface processing device 412 is configured to process a second surface of the product. The first surface is an outer surface 420 of the product, and the second surface is an inner surface 416 of the product.

[0094] The surface processing device 412 can be a variety of different types of processing devices 412. In an example where the additive manufacturing system 304 includes a single surface processing device 412, the surface processing device 412 includes an aperture 476 configured to emit electromagnetic energy (see, Figure 5 , 7and 10). In an example where the additive manufacturing system 304 includes two or more surface-processing devices 412, the aperture is a first aperture 476, and the surface-processing device 412 further includes a second aperture 476 that is opposite the first aperture 476 and is configured to emit electromagnetic energy (see, Figure 4 , 6 and 9). In one example, the first and second apertures 476 can have substantially the same shape. In another example, the first aperture can have a first shape and the second aperture can have a second shape that is different from the first shape. In one aspect, the first aperture 476 can be the second end 464 of the first laser delivery device 456 and the second aperture 476 can be the second end 464 of the second laser delivery device 456.

[0095] Continue to refer to Figure 4-12 and specifically refer to Fig. 9 , illustrated ( Figure 3 ) is an example of a block diagram of an additive manufacturing apparatus 300. The additive manufacturing apparatus 300 includes an additive manufacturing system 304, a surface processing device 480, a power source 984, a laser source 452, a drive mechanism 988, a material source 992, a processor and / or a central processing unit (CPU) 996, a memory 900, an input device 904, and an output device 908. The apparatus 300 is not limited to only including Fig. 9 The above-identified parts arranged as shown in and having the features and functions described herein. Rather, the device 300 can include more, less or different parts, and can have more, less or different features and functions, and all such possibilities are intended to be within the spirit and scope of the present disclosure.

[0096] Continue to refer to Fig. 9 , power supply 984 is configured to provide power to parts of device 300 as needed. Power supply 984 can be a single power supply, or can be composed of multiple power supplies that work together to provide the necessary power output. Alternatively, multiple power supplies can operate independently and can individually supply power to specific parts of device 300. Power supply 984 can be an AC or DC power supply, or a combination of AC and DC can be utilized.

[0097] The laser source 452 generates a laser beam 944 and transmits it to one or more laser outputs 912 (e.g., Figure 6) for emission. The laser beams 944 emitted from one or more laser outputs 912 converge into a nexus or point of convergence. The material source 992 supplies raw materials to the additive manufacturing system 304 to be used to manufacture the product 404. The raw materials can be any type of material (e.g., powder, liquid, solid, etc.) in any form type. The material is discharged from one or more material outputs 916 disposed in the additive manufacturing system 304. The material output 916 can include a variety of configurations, such as, for example, holes, nozzles, etc. In the illustrated example, the additive manufacturing system 304 includes a single material output 490 ( Fig. 9 916), which is composed of holes 490 (aligned with the nodes or convergence points of multiple laser output portions 912) Fig. 9 916). The feedstock is released from the material output 916 and enters the node or convergence point of the laser output 912, where the material is melted to form a weld pool. As the additive manufacturing system 304 advances relative to the product being formed, the melted material forms a new layer L of the product 404. Once the material leaves the weld pool, the melted material begins to cool and harden.

[0098] See also Fig. 9 , the processor 900 or CPU 496 communicates with and / or controls various parts in the device 300. The memory 900 may be a computer-readable storage medium 900 and is configured to store data required for the operation of the additive manufacturing system 304. The computer-readable storage medium 900 is any medium that can be used to store information that can be accessed by the processor 996 later. The computer-readable storage medium 900 may include computer memory and data storage devices. The computer memory may be a fast access memory and may be used to run program instructions that can be executed by the processor 996. The computer memory may include random access memory (RAM), flash memory, and read-only memory (ROM). The data storage device may be a physical device and may be used to store any information or computer program that can be accessed by the processor 996, such as an operating system, a computer program, a program module, and program data. The data storage device and its associated computer-readable storage medium provide storage of computer-readable instructions, data structures, program modules, and other data for the system. Data storage devices may include magnetic media, such as floppy disks, hard disks, and magnetic tapes; optical media, such as compact disks (CDs), digital video disks (DVDs), and Blu-ray disks; and solid-state memory, such as random access memory (RAM), flash memory, and read-only memory (ROM).

[0099] In some aspects of the apparatus 300, the memory 900 includes data packets 920 consisting of data required for the controlled operation of the additive manufacturing system 304. One data packet 920 may contain data required to control the additive manufacturing head 908, while another data packet 920 may contain data required to control the surface processing device 480. The surface processing device 480 is connected to the additive manufacturing system 304 and in its trailing orientation. The surface processing device 480 processes one or more surfaces of the product after material has been deposited by the additive manufacturing system 304. The processor 996 communicates with the memory 900 to retrieve the necessary data for controlling the orientation of the surface processing device 480 relative to the additive manufacturing system 304.

[0100] Unless otherwise indicated, the subject matter of the present disclosure will be described with reference to actions and symbolic representations of operations performed by one or more computers or computer systems. Therefore, it will be understood that these actions and operations, which are sometimes referred to as computer execution, include manipulations performed by the processor 996 of the device 300 via electrical signals representing data in a structured form. The operation converts data or maintains it in a specific location in the memory 900 of the device 300, which reconfigures or otherwise changes the operation of the device 300 in a manner familiar to those skilled in the art. The data structure that holds the data is the physical location of the memory, which has a specific property defined by the data format. However, although the subject matter of the present application is described in the foregoing context, as will be understood by those skilled in the art, this is not meant to be restrictive, because some of the actions and operations described herein may also be implemented in hardware, software and / or firmware and / or some combination thereof.

[0101] Further references Fig. 9 , input device 904 allows a user to input data into device 300. Input device 904 can have a variety of configurations, all of which are intended to be within the spirit and scope of the present disclosure. For example, input device 904 can be a keyboard, a keypad, a touch screen display, an actuator, a switch, a dial, a sliding mechanism, or any other type of mechanical, electrical, or electromechanical device configured to allow a user to at least partially input information and / or control device 300. In addition, device 300 can include multiple input devices 904.

[0102] Continue to refer to Fig. 9, output device 908 outputs information from device 300 that can be perceived by a user. Output device 908 can have a variety of configurations, all of which are intended to be within the spirit and scope of the present disclosure. For example, output device 908 can be a display, monitor, alphanumeric indicator, lighting device (e.g., light bulb, LED, LED array, etc.), printer or other image generating device, or any other type of mechanical, electrical or electromechanical device configured to output information from device 300 in a form that can be perceived by a user. In addition, device 300 may include multiple output devices 908.

[0103] The drive mechanism 988 is connected to the additive manufacturing system 304 and can be controlled by the processor 996 to move the additive manufacturing system 304 in a desired manner. Alternatively, the additive manufacturing system 304 can remain stationary and the product manufactured by the device 300 can be supported on a base or table that can be moved relative to the additive manufacturing system 304 by the drive mechanism 988. In either example, the drive mechanism 988 provides the desired relative translational motion between the product 904 being formed and the additive manufacturing device 300. In some aspects of the device 300, the drive mechanism 988 includes a single drive mechanism for performing all necessary relative translational motions. In other aspects of the device 300, the drive mechanism 988 includes multiple cooperating drive mechanisms.

[0104] The surface processing device 480 is configured to process one or more surfaces of the product formed by the additive manufacturing system 304. The surface processing device 480 lags behind the additive manufacturing system 304 to process the material deposited by the additive manufacturing system 304. The surface processing device 480 can process the surface of the product being formed in various ways. For example, in the illustrated device 300, the surface processing device 480 can smooth the surface of the product or otherwise reduce the roughness. This example of surface processing is not intended to limit the present disclosure. To be precise, the device 300 is capable of performing any type of surface processing, such as, for example, coating or heat treatment, and all such possibilities are intended to be within the spirit and scope of the present disclosure. When the product is being formed, the surface processing device 480 can process a portion of the product 404 in situ. In some aspects of the present disclosure, the surface processing device 480 can process a single layer of material L deposited by the additive manufacturing system 304. In other aspects, the surface processing device 480 can process two or more layers of material L deposited by the additive manufacturing system 304. The surface-processing device 480 may also be configured to process multiple layers L of a product formed by the additive manufacturing system 304 .

[0105] Now refer to Figure 4-12In the illustrated apparatus 300, the surface processing device 480 includes a first surface processing device 412 and a second processing device 412. The first and second processing devices 412 may include a variety of types of processing devices, and thus can process the surface of the product formed by the additive manufacturing system 304 in various ways. In the illustrated apparatus 300, the first and second surface processing devices 412 are laser emitting devices. The surface processing device 480 also includes a first drive mechanism that is configured to move the first and second surface processing devices 412 between a first or active position and a second or idle position, wherein in the first or active position, the first and second surface processing devices 412 are configured to process the surface of the product formed by the additive manufacturing system 304 (see, for example Figure 6 solid line), and in the second or idle position, neither the first or second surface processing device 412 is configured to process the surface of the product (as shown, for example, using Figure 6 In one example, the first drive mechanism is a servo motor or a stepper motor. In another example, the first drive mechanism can be air-driven (e.g., rotary, linear, etc.), hydraulically driven (e.g., rotary, linear, etc.), or electromagnetically driven (e.g., solenoid).

[0106] In some aspects of the present disclosure, the apparatus 300 may include only a single surface-processing device 412 to process a single surface of a product formed by the additive manufacturing system 304. Fig. 9 1 and 2 are shown in dashed lines to illustrate optional aspects of the present disclosure.

[0107] For example, refer to Fig. 9 , the surface-processing device 480 further includes a mechanism 426 for rotatably positioning the housing 424 of the surface-processing device 480 relative to the additive manufacturing system 304. In some aspects, the mechanism 426 can be an open-frame servo motor connected to the additive manufacturing system 304. In other aspects, the mechanism 426 can be other types of drive mechanisms and can have other configurations.

[0108] The surface processing device 412 may also include a second laser source 932 configured to generate a laser beam 444 to be optically communicated with the first and second surface processing devices 412. In this example, the second laser source 932 will provide the laser beam 444 for the surface processing operation, and the laser source 452 will provide the laser beam 444 for the additive manufacturing system 304.

[0109] like Fig. 9As shown, the lines connecting the various parts of the device 300 can represent a variety of interactions between the various parts of the device 300. In addition, such interactions between the parts can occur in either direction or can occur in both directions at the same time. The interactions may include, but are not limited to, the transmission of electrical energy or power for the purpose of powering the parts, the communication of electrical data between the parts, the transmission of physical substances between the parts, the mechanical connection, connection, attachment or engagement between the parts, or any other type of interaction that can occur in the additive manufacturing device 300 in one or more aspects thereof. The dashed lines connecting the various parts of the device 300 can represent interactions that are similar in function and purpose to the interactions represented by the solid lines, however, the interactions represented by the dashed lines relate to optional aspects of the present disclosure. Similarly, the parts represented by the dashed lines represent optional aspects of the present disclosure.

[0110] See for example Figure 4 and 9 In one example, a surface processing device 480 for an additive manufacturing system 304 is provided. The surface processing device 480 includes a housing 424 configured to be connected to the additive manufacturing system 304; and a surface processing device 412 connected to the housing 424. The surface processing device 412 includes one of a mechanical device or an optical device. The surface processing device 412 is configured to move relative to the additive manufacturing system 304. In one aspect, the housing 424 is rotatably connected to the additive manufacturing system 304. In this aspect, the surface processing device 480 further includes a mechanism 426 for rotatably positioning the housing 424 relative to the additive manufacturing head 408.

[0111] For example, Figure 4 and 6 As shown in FIG. 4 , the surface-processing device 412 has a trailing orientation relative to the additive-manufacturing system 304 . The surface-processing device 412 is configured to be spaced apart from a surface of the product 404 formed by the additive-manufacturing system 304 .

[0112] Now refer to Figure 4-10In one aspect, the surface-processing device 412 is configured to emit a laser beam 444. The surface-processing device 480 further includes a laser energy source 452, 932 and a laser delivery device 456 connected to the laser energy source 452, 932 to deliver the laser beam 444 from the laser energy source 452, 932 to the surface of the product formed by the additive manufacturing system 304. The surface-processing device 412 also includes a support member 448 connected to the housing 424, and the laser delivery device 456 includes a first end 460 connected to the laser energy source 452, 932 and a second end 464 connected to the support member 448. In one aspect, the second end 464 of the laser delivery device 456 is generally polygonal in shape to emit a laser beam 444 having a generally polygonal cross-section. In another aspect, the second end 464 of the laser delivery device 456 is generally rectangular in shape to emit a laser beam 444 having a generally rectangular cross-section. In a further aspect, the laser delivery device 456 is configured to emit a laser beam 444 having a cross-section having a substantially arcuate perimeter. In one aspect, the laser delivery device is a fiber optic cable 456.

[0113] The surface-processing device 412 is configured to engage a product formed by the additive manufacturing system 304. In one aspect, the surface-processing device 412 is configured to optically engage a product formed by the additive manufacturing system 304.

[0114] In one aspect, the additive manufacturing system 304 is configured to form a product from a plurality of layers L (see Figure 4 ), and the surface processing device 412 is configured to process at least one layer of the plurality of layers L (see, Figure 4 and 10 ). In another aspect, the additive manufacturing system 304 is configured to form a product from a plurality of layers L, and the surface processing device 412 is configured to process two or more of the plurality of layers L simultaneously.

[0115] The surface-processing device 412 is configured to move between a first (active) position and a second (idle) position relative to the additive manufacturing system 304, wherein in the first (active) position, the surface-processing device 412 is capable of processing a product formed by the additive manufacturing system 304 (see, e.g., Figure 6 ), and in the second (idle) position, the surface processing device 412 is not able to process the product (see, for example, Figure 64 and 4. In one aspect, the surface processing device 412 is rotatably connected to the housing 424 and rotates between a first position and a second position. The surface processing device 480 also includes a connecting member 446 and a support member 448. The connecting member 446 connects the housing 424 and the support member 448 and is between the housing 424 and the support member 448, and the support member 448 supports the surface processing device 412. In one aspect, the support member 448 is configured to rotate relative to the connecting member 446. The support member 448 is configured to rotate around the longitudinal center axis of the connecting member 446.

[0116] In some examples, the apparatus 300 includes a plurality of surface-processing devices 412. In these aspects, the first surface-processing device 412 and the second surface-processing device 412 are spaced apart from the first surface-processing device 412. Both the first and second surface-processing devices 412 are in a trailing orientation relative to the additive manufacturing system 304. The first surface-processing device 412 is configured to process a first surface of a product formed by the additive manufacturing system 304, and the second surface-processing device 412 is configured to process a second surface of the product. In one aspect, the first surface is an outer surface 420 of the product 404, and the second surface is an inner surface 416 of the product 404.

[0117] The surface processing device 480 further includes a guide member 468. The guide member 468 is configured to engage a product formed by the additive manufacturing system 304 and is configured to orient the surface processing device 412 relative to the product. The guide member 468 is configured to space the surface processing device 412 a distance from the surface of the product. In one aspect, the guide member 468 is a guide roller. In one aspect, the surface processing device 412 is an optical device. The surface processing device 412 is configured to smooth the surface of the product formed by the additive manufacturing system 304. In one aspect, the surface processing device 412 is configured to rotate about at least one axis 428, 447, 470. In another aspect, the surface processing device 212 is configured to rotate about at least two axes 428, 447, 470. In a further aspect, the surface processing device 412 is configured to rotate about three axes 428, 447, 470. In one example of the device 300, the surface processing device 412 includes a hole 476 configured to emit electromagnetic energy.

[0118] Further, the present disclosure includes implementations according to the following clauses:

[0119] aspect

[0120] The present disclosure provides the following aspects, among others, each of which may be viewed as optionally including any optional aspects.

[0121] Clause 1. A method for powder bed additive manufacturing, comprising:

[0122] defining a uniformly spaced raster path for laser travel at a predetermined travel rate, wherein the raster path alternates back and forth within a swath width of less than 0.5 mm so that the power density level of the laser is at least 80% of maximum power, and the predetermined travel rate produces a travel speed in a scan width direction of not less than 1,000 mm / s;

[0123] depositing a powder layer onto a substrate; and

[0124] The laser hardens a certain amount of powder according to a defined raster path and laser power setting.

[0125] Clause 2. The method of clause 1, wherein the grating path comprises a lateral distance of about 0.1 mm to about 5 mm.

[0126] Clause 3. The method of clause 1 or 2, wherein the grating path comprises a lateral distance of about 0.5 mm to about 1 mm.

[0127] Clause 4. The method of any one of clauses 1 to 3, wherein the raster path comprises a scan width distance of about 0.08 mm to about 0.2 mm.

[0128] Clause 5. The method of any one of clauses 1 to 4, wherein the raster path comprises a scan width distance of about 0.15 mm to about 0.18 mm.

[0129] Clause 6. The method according to any one of clauses 1 to 5, wherein the raster path comprises about 5,000 laser weld passes / m 2 Up to about 25,000 laser welds / m 2 Scan density.

[0130] Clause 7. The method according to any one of clauses 1 to 6, wherein the raster path comprises about 8,750 laser weld passes / m 2 Up to approximately 18,750 laser weld passes / m 2 Scan density.

[0131] Clause 8. The method of any one of Clauses 1 to 7, wherein the raster path comprises an average hatch spacing of about 0.04 mm to about 2 mm.

[0132] Clause 9. The method of any one of Clauses 1 to 8, wherein the raster path comprises an average hatch spacing of about 0.09 mm to about 0.11 mm.

[0133] Clause 10. The method of any of Clauses 1 to 9, wherein the predetermined travel rate produces a travel speed of about 1,700 mm / s to about 2,200 mm / s in the scan width direction.

[0134] Clause 11. The method of any of Clauses 1 to 10, wherein the predetermined travel rate produces a travel speed in the transverse direction of not less than 1,000 mm / s.

[0135] Clause 12. The method of any of Clauses 1 to 11, wherein the predetermined travel rate produces a travel speed in the transverse direction of about 1,700 mm / s to about 2,200 mm / s.

[0136] Clause 13. The method of any one of Clauses 1 to 12, wherein the laser has a laser beam average power of about 200W to about 1,000W.

[0137] Clause 14. The method of any one of Clauses 1 to 13, wherein the laser has a laser beam average power of about 400W to about 500W.

[0138] Clause 15. The method of any of Clauses 1 to 14, wherein the laser comprises a laser beam having a beam diameter of about 0.05 mm to about 0.2 mm.

[0139] Clause 16. The method of any one of Clauses 1 to 15, wherein the laser comprises a laser beam having a beam diameter of about 0.1 mm to about 0.14 mm.

[0140] Clause 17. The method of any one of Clauses 1 to 16, wherein the strip width is from about 0.5 mm to about 1 mm.

[0141] Clause 18. The method of any of Clauses 1 to 17, wherein the laser comprises a laser beam disposed at an angle of incidence of about 85° to about 95° relative to the laser contact surface of the substrate.

[0142] Clause 19. The method of any one of Clauses 1 to 18, further comprising pre-treating the powder with an average power of the laser beam of about 50 W to about 400 W.

[0143] Clause 20. The method according to any one of clauses 1 to 19, wherein the pretreatment is performed after depositing the powder layer onto the substrate.

[0144] Clause 21. The method according to any one of clauses 1 to 20, wherein the powder is selected from aluminum, aluminum alloys, titanium, titanium alloys, nickel, nickel alloys, stainless steel, alloy steels, cobalt alloys, plastics, polymers, nylons, or combinations thereof.

[0145] Clause 22. The method according to any one of clauses 1 to 21, wherein the powder is selected from aluminum, aluminum alloys, titanium, titanium alloys, or combinations thereof.

[0146] Clause 23. The method of any one of clauses 1 to 22, wherein the substrate comprises aluminum, an aluminum alloy, titanium, a titanium alloy, nickel, a nickel alloy, stainless steel, a steel alloy, a cobalt alloy, a plastic, a polymer, nylon, or a combination thereof.

[0147] Clause 24. The method of any one of Clauses 1 to 23, wherein the substrate comprises aluminum, an aluminum alloy, titanium, a titanium alloy, or a combination thereof.

[0148] Clause 25. A method for additive manufacturing, comprising:

[0149] depositing a layer of material onto a substrate; and

[0150] The material is treated with a laser by moving the laser in a raster path relative to the substrate at a travel speed of not less than 1,000 mm / s in the scan width direction, wherein:

[0151] The grating path includes a lateral distance of about 0.1 mm to about 5 mm

[0152] The raster path includes a scan width distance of about 0.08 mm to about 0.2 mm,

[0153] The grating path includes an average hatch spacing of about 0.04 mm to about 2 mm,

[0154] The laser has an average laser beam power of about 200 W to about 1,000 W, and

[0155] The laser includes a laser beam having a beam diameter of about 0.05 mm to about 0.2 mm.

[0156] Clause 26. The method of Clause 25, wherein the grating path comprises a lateral distance of about 0.5 mm to about 1 mm.

[0157] Clause 27. The method of clause 25 or 26, wherein the raster path comprises a scan width distance of about 1 mm to about 5 mm.

[0158] Clause 28. The method according to any one of clauses 25 to 27, wherein the raster path comprises about 5,000 laser weld passes / m 2 Up to about 25,000 laser welds / m 2 Scan density.

[0159] Clause 29. The method of any one of Clauses 25 to 28, wherein the raster path comprises an average hatch spacing of about 0.09 mm to about 0.11 mm.

[0160] Clause 30. The method of any one of Clauses 25 to 29, wherein the travel speed in the scan direction is about 1,700 mm / s to about 2,200 mm / s.

[0161] Clause 31. The method of any of Clauses 25 to 30, wherein treating the material with the laser comprises moving the laser at a travel speed in a lateral direction of about 1,700 mm / s to about 2,200 mm / s.

[0162] Clause 32. The method of any one of Clauses 25 to 31, wherein the laser has a laser beam average power of about 400W to about 500W.

[0163] Clause 33. The method of any of Clauses 25 to 32, wherein the laser comprises a laser beam having a beam diameter of about 0.1 mm to about 0.14 mm.

[0164] Clause 34. The method of any of Clauses 25 to 33, wherein the laser comprises a laser beam disposed at an angle of incidence of about 85° to about 95° relative to the laser contact surface of the substrate.

[0165] Clause 35. The method of any of Clauses 25 to 34, further comprising pre-treating the material with an average power of the laser beam of about 50W to about 400W.

[0166] Clause 36. The method of any one of Clauses 25 to 35, wherein the pretreatment is performed after depositing the material layer onto the substrate.

[0167] Clause 37. The method according to any one of clauses 25 to 36, wherein the material is selected from aluminum, aluminum alloy, titanium, titanium alloy, nickel, nickel alloy, stainless steel, alloy steel, cobalt alloy, plastic, polymer, nylon or a combination thereof.

[0168] Clause 38. The method according to any one of Clauses 25 to 37, wherein the material is selected from aluminum, aluminum alloys, titanium, titanium alloys, or combinations thereof.

[0169] Clause 39. The method of any one of Clauses 25 to 38, wherein the substrate comprises aluminum, aluminum alloy, titanium, titanium alloy, nickel, nickel alloy, stainless steel, alloy steel, cobalt alloy, plastic, polymer, nylon, or a combination thereof.

[0170] Clause 40. The method of any one of Clauses 25 to 39, wherein the substrate comprises aluminum, an aluminum alloy, titanium, a titanium alloy, or a combination thereof.

[0171] In general, the present disclosure provides methods for additive manufacturing of, for example, high-strength alloys. The methods of the present disclosure can suppress residual stress cracks by changing the hardening rate of the alloy during processing. For example, by changing the strip width of the laser to 1 / 10 of the normal operating parameters, the amplitude of the laser travel path oscillation within the strip is reduced. Therefore, for a set travel speed, the laser head (of the device manufacturing system) moves faster along the strip. Faster movement allows the use of increased laser power. In addition, faster movement also allows the previously scanned weld pool to be completely cooled before the next line in the raster is scanned, resulting in a significantly slower hardening front, which can reduce the hardening shrinkage rate (and by extension, the strain rate applied to the liquid film at the grain boundaries in the melt).

[0172] Although the foregoing is directed to examples of the present disclosure, other and further examples of the present disclosure may be envisioned without departing from the basic scope of the present disclosure. In addition, although the foregoing is directed to methods applied to vehicle parts such as those in the aerospace industry, examples of the present disclosure may be directed to other applications not related to aircraft, such as applications in the automotive industry, the marine industry, the energy industry, wind turbines, satellites, etc.

[0173] Descriptions of various examples of the present disclosure have been given for illustrative purposes, but are not intended to be exhaustive or limited to the disclosed examples. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described examples. The terms used herein are selected to best explain the principles of the examples, practical applications or technical improvements to the technology found on the market, or to enable other persons of ordinary skill in the art to understand the examples disclosed herein. Although the foregoing is directed to examples of the present disclosure, other and further examples of the present disclosure may be envisioned without departing from the basic scope of the present disclosure.

Claims

1. A method for powder bed additive manufacturing, comprising: defining a uniformly spaced grating path for a laser to travel at a predetermined travel rate including a scan width direction and a lateral direction perpendicular to the scan width direction, wherein the laser includes a beam diameter, wherein the grating path alternates back and forth in the scan width direction to form a laser sheet having a stripe width of 0.1 mm to 0.18 mm, wherein the laser has an average laser beam power of 200 W to 1,000 W, and the predetermined travel rate produces a travel speed in the scan width direction of not less than 1,000 mm / s, wherein the stripe width is greater than the beam diameter; depositing a powder layer onto a substrate; and The laser is caused to harden a certain amount of powder according to a defined raster path and laser power setting. 2 . The method of claim 1 , wherein the grating path comprises a lateral distance in the lateral direction of 0.1 mm to 5 mm. The method according to claim 2 , wherein the lateral distance in the lateral direction is 0.5 mm to 1 mm. The method according to claim 1 , wherein the strip width is 0.15 mm to 0.18 mm.

5. The method according to any one of claims 1 to 4, wherein the raster path comprises 5,000 laser weld passes / m 2 Up to 25,000 laser welds / m 2 Scan density.

6. The method according to claim 5, wherein the scanning density is 8,750 laser welds / m 2 Up to 18,750 laser weld passes / m 2 .

7. A method according to any one of claims 1 to 4, wherein the raster path comprises an average hatch spacing in the transverse direction of 0.04 mm to 2 mm. The method of claim 7 , wherein the average hatch spacing is 0.09 mm to 0.11 mm.

9. The method of any one of claims 1 to 4, wherein the predetermined travel rate produces a travel speed of not less than 1,000 mm / s in the transverse direction.

10. The method of claim 9, wherein the predetermined travel rate produces a travel speed of 1,700 mm / s to 2,200 mm / s in the transverse direction.

11. The method according to any one of claims 1 to 4, wherein the beam diameter is 0.05 mm to 0.2 mm.

12. The method of any one of claims 1 to 4, wherein the laser comprises a laser beam disposed at an incident angle of 85° to 95° relative to a laser contact surface of the substrate.

13. The method according to any one of claims 1 to 4, further comprising pre-treating the powder with an average laser beam power of 50 W to 400 W, wherein the pre-treatment is performed after depositing the powder layer onto the substrate.

Images