具体实施方式：
[0023]While various embodiments of the invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed.
[0024]The term “three-dimensional printing” (also “3D printing”), as used herein, generally refers to a process or method for generating a 3D part (or object). For example, 3D printing may refer to sequential addition of material layer or joining of material layers or parts of material layers to form a three-dimensional (3D) part, object, or structure, in a controlled manner (e.g., under automated control). In the 3D printing process, the deposited material can be fused, sintered, melted, bound or otherwise connected to form at least a part of the 3D object. Fusing the material may include melting or sintering the material. Binding can comprise chemical bonding. Chemical bonding can comprise covalent bonding. Examples of 3D printing include additive printing (e.g., layer by layer printing, or additive manufacturing). The 3D printing may further comprise subtractive printing.
[0025]The term “part,” as used herein, generally refers to an object. A part may be generated using 3D printing methods and systems of the present disclosure. A part may be a portion of a larger part or object, or an entirety of an object. A part may have various form factors, as may be based on a computer model (model) of such part, such as a computer aided design (CAD) model. Such form factors may be predetermined.
[0026]The term “composite material,” as used herein, generally refers to a material made from two or more constituent materials with different physical or chemical properties that, when combined, produce a material with characteristics different from the individual components.
[0027]The term “fuse”, as used herein, generally refers to binding, agglomerating, or polymerizing. Fusing may include melting, softening or sintering. Binding may comprise chemical binding. Chemical binding may include covalent binding. The energy source resulting in fusion may supply energy by a laser, a microwave source, source for resistive heating, an infrared energy (IR) source, a ultraviolet (UV) energy source, hot fluid (e.g., hot air), a chemical reaction, a plasma source, a microwave source, an electromagnetic source, or an electron beam. Resistive heating may be joule heating. A source for resistive heating may be a power supply. The hot fluid may have a temperature greater than or equal to about 25 Celsius (° C.), 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., 150° C., 200° C., 250° C., 300° C., 350° C., 400° C., 450° C., 500° C., or more. The hot fluid may have a temperature that may be less than or equal to about 500° C., 450° C., 400° C., 350° C., 300° C., 250° C., 200° C., 150° C., 100° C., 50° C., or less. The hot fluid may have a temperature from about 25° C. to 500° C., 25° C. to 400° C., 25° C. to 300° C., 25° C. to 200° C., 25° C. to 100° C., 25° C. to 50° C., 100° C. to 500° C., 100° C. to 400° C., 100° C. to 300° C., 100° C. to 200° C., 300° C. to 500° C., or 300° C. to 400° C. The hot fluid may have a temperature that may be selected to soften or melt a material used to print an object. The hot fluid may have a temperature that may be at or above a melting point or glass transition point of a polymeric material. The hot fluid can be a gas or a liquid. In some examples, the hot fluid may be argon or air.
[0028]The term “adjacent” or “adjacent to,” as used herein, generally refers to ‘on,’‘over, ‘next to,’ adjoining,’‘in contact with,’ or ‘in proximity to.’ In some instances, adjacent components are separated from one another by one or more intervening layers. For example, a first layer adjacent to a second layer can be on or in direct contact with the second layer. As another example, a first layer adjacent to a second layer can be separated from the second layer by at least one third layer. The one or more intervening layers may have a thickness that may be greater than or equal to about 0.5 nanometers (nm), 1 nm, 10 nm, 100 nm, 500 nm, 1 micrometer (micron), 10 microns 20 microns, 30 microns, 40 microns, 50 microns, 60 microns, 70 micron, 80 microns, 90 microns, 100 microns, 200 microns, 300 microns, 400 microns, 500 microns, 600 microns, 700 microns, 800 microns, 900 microns, 1000 microns or more. The one or more intervening layers may have a thickness that may be less than or equal to about 1000 micrometers, 900 microns, 800 microns, 700 microns, 600 microns, 500 microns, 400 microns, 300 microns, 200 microns, 100 microns, 90 microns, 80 microns, 70 microns, 60 microns, 50 microns, 40 microns, 30 microns, 20 micron, 10 microns, 1 micron, 500 nm, 100 nm, 50 nm, 10 nm, 1 nm, 0.5 nm, or less. The one or more intervening layers may have a thickness level of from about 0.5 nm to 1000 microns, 0.5 nm to 800 microns, 0.5 nm to 600 microns, 0.5 nm to 400 microns, 0.5 nm to 200 microns, 0.5 nm to 100 microns, 0.5 nm to 50 microns, 0.5 nm to 10 microns, 0.5 nm to 1 microns, 0.5 nm to 500 nm, 0.5 nm to 100 nm, 0.5 nm to 10 nm, 0.5 nm to 1 nm, 100 nm to 1000 microns, 100 nm to 800 microns, 100 nm to 600 microns, 100 nm to 400 microns, 100 nm to 200 microns, 100 nm to 100 microns, 100 nm to 50 microns, 100 nm to 10 microns, 100 nm to 1 microns, 100 nm to 500 nm, 1 micron to 1000 microns, 1 micron to 800 microns, 1 micron to 600 microns, 1 micron to 400 microns, 1 micron to 200 microns, 1 micron to 100 microns, 1 micron to 50 microns, 1 micron to 10 microns, 100 microns to 1000 microns, 100 microns to 800 microns, 100 microns to 600 microns, 100 microns to 400 microns, 100 microns to 200 microns, 500 microns to 1000 microns, 500 microns to 800 microns, or 500 microns to 600 microns.
[0029]Examples of 3D printing methodologies comprise wire, granular, laminated, light polymerization, VAT photopolymerization, material jetting, binder jetting, sheet lamination, directed energy deposition, extrusion, power bed and inkjet-based 3D printing. 3D printing can comprise robo-casting, fused deposition modeling (FDM) or fused filament fabrication (FFF). Wire 3D printing can comprise electron beam freeform fabrication (EBF3). Granular 3D printing can comprise direct metal laser sintering (DMLS), electron beam melting (EBM), selective laser melting (SLM), selective heat sintering (SHS), or selective laser sintering (SLS). Power bed and inkjet head 3D printing can comprise plaster-based 3D printing (PP). Laminated 3D printing can comprise laminated object manufacturing (LOM). Light polymerized 3D printing can comprise stereo-lithography (SLA), digital light processing (DLP) or laminated object manufacturing (LOM).
[0030]Whenever the term “at least,”“greater than,” or “greater than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “at least,”“greater than” or “greater than or equal to” applies to each of the numerical values in that series of numerical values. For example, greater than or equal to 1, 2, or 3 is equivalent to greater than or equal to 1, greater than or equal to 2, or greater than or equal to 3.
[0031]Whenever the term “no more than,”“less than,” or “less than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “no more than,”“less than,” or “less than or equal to” applies to each of the numerical values in that series of numerical values. For example, less than or equal to 3, 2, or 1 is equivalent to less than or equal to 3, less than or equal to 2, or less than or equal to 1.
Methods for Forming 3D Objects by Direct Energy Deposition
[0032]The present disclosure provides methods and systems for forming a 3D object using direct energy deposition. Such deposition may be performed using a material feedstock (or build material) or multiple feedstocks. The feedstock may be a filament material. The filament material may be a composite filament. The deposition may be performed in the absence of extrusion.
[0033]A method for printing at least a portion of a three-dimensional (3D) object may comprise receiving, in computer memory, a model of the 3D object and subsequently directing at least one filament material (or feedstock) from a source of the at least one filament material towards a build platform configured to support the 3D object. This may deposit a first layer corresponding to a portion of the 3D object adjacent to the build platform in accordance with the model of the 3D object. Next, the at least one filament material may be used to deposit a second layer corresponding to at least a portion of the 3D object. The second layer may be deposited in accordance with the model of the 3D object. While the second layer may be deposited, at least a first energy beam from at least one energy source may be used to selectively heat a first portion of the first layer and a second portion of the at least one filament material. The first portion may be brought in contact with the second portion during heating or subsequent to heating. Such heating may soften, melt or liquefy the first portion and/or the second portion. The heating may be selective such that at most portions of the first layer and the at least one filament material are heated. This may be repeated for additional layers or portions of layers of the 3D object.
[0034]In another aspect, the present disclosure provides a system for printing at least a portion of a three-dimensional (3D) object. The system may comprise a source of at least one filament material, computer memory configured to receive a model of the 3D object, a least one energy source configured to provide at least one energy beam, and/or one or more computer processors operatively coupled to the computer memory and the at least one energy source. The one or more computer processors may be individually or collectively programmed to (i) direct the at least one filament material from the source of the at least one filament material towards a build platform configured to support the 3D object, thereby depositing a first layer corresponding to a portion of the 3D object adjacent to the build platform, which first layer is deposited in accordance with the model of the 3D object from the computer memory; (ii) direct the at least one filament material to deposit a second layer corresponding to the at least the portion of the 3D object, which second layer is deposited in accordance with the model of the 3D object; and (iii) while the second layer is being deposited, direct the at least one energy source to provide the at least one energy beam to selectively heat a first portion of the first layer and a second portion of the at least one filament material, which first portion is brought in contact with the second portion.
[0035]In another aspect, the present disclosure provides a system for printing at least a portion of a three-dimensional (3D) object. The system may comprise a source of at least one feedstock, computer memory configured to receive a model of the 3D object, and/or one or more computer processors operatively coupled to the computer memory. The one or more computer processors may be individually or collectively programmed to (i) direct use of the at least one feedstock from the source of the at least one feedstock to deposit a first layer adjacent to a build platform, which first layer is deposited in accordance with the model of the 3D object, (ii) direct use of the at least one feedstock from the source of the at least one feedstock to deposit a second layer adjacent to the first layer, which second layer is deposited in accordance with the model of the 3D object.
[0036]In some cases, depositing of the first layer corresponding to the at least the portion of the 3D object may be performed without heating of the at least one filament material.
[0037]In some cases, at least one additional filament material from a source of the at least one additional filament material may be used to deposit an adhesion layer adjacent to the build platform to support the 3D object. The at least one additional filament material may be the same as the at least one filament material. The at least one additional filament material may be different than the at least one filament material. The at least one adhesion layer may not be part of the 3D object.
[0038]In some cases, one or more additional layers may be deposited over the first layer and the second layer. As described in more detail elsewhere herein, layers may be compacted or compressed during or subsequent to deposition. For example, the first layer may be compacted or compressed during or subsequent to deposition of the first layer or during or subsequent to deposition of the second layer against the first layer. In some cases, the second layer may be compacted subsequent to heating the portion of the first layer and the second portion of the at least one filament material.
[0039]Feedstock usable by methods and systems of the present disclosure may be a filament having various form factors or geometric shapes, such as a cross-section that may be circular, oval, triangular, square, rectangular, pentagonal, hexagonal, heptagonal, octagonal, nonagonal, decagonal, star-shaped, or partial shapes or combinations of shapes thereof. The filament may not be a two-dimensional tape. The feedstock may be formed of a composite material, such as a material comprising one or more polymeric materials and one or more reinforcing materials. In some examples, the feedstock may comprise a polymer filament and a reinforcing filament interwoven or as a bundle. In some examples the at least one feedstock is not a tape.
[0040]In some embodiments, the at least one filament material is a bundle of filament materials. In some embodiments, the bundle of filament material comprises a polymeric material and a reinforcing material. In some embodiments, the filament material comprises one or more elements selected from the group consisting of continuous fiber, long fiber, short fiber, and milled fiber. In some embodiments, the filament material comprises one or more elements selected from the group consisting of carbon nanotube, graphene, Bucky ball(s), and metallic material (e.g., elemental metal or metal alloy).
[0041]The feedstock may have a cross sectional ratio of a first dimension to a second dimension (orthogonal to the first dimension), such as width to height, that may be greater than or equal to about 1:50, 1:40, 1:30, 1:20, 1:10, 1:5, 1:4, 1:3, 1:2.5, 1:2, 1:1.1, 1:1, 1.1:1, 2:1, 2.5:1, 3:1, 4:1, 5:1, 10:1, 20:1, 30:1, 40:1, 50:1, 100:1, 200:1, 300:1, 500:1, 1000:1, or more. The feedstock may have a cross sectional ratio of a first dimension to a second dimension (orthogonal to the first dimension), such as width to height, that may be less than or equal to about 1000:1, 500:1, 400:1, 300:1, 200:1, 100:1, 50:1, 40:1, 30:1, 20:1, 10:1, 5:1, 4:1, 3:1, 2.5:1, 2:1, 1.1:1, 1:1, 1:1.1, 1:2, 1:2.5, 1:3, 1:4, 1:5, 1:10, 1:20, 1:30, 1:40, 1:50, or less. The feedstock may have a cross sectional ratio of a first dimension to a second dimension (orthogonal to the first dimension) that may be from about 1000:1 to 1:50, 500:1 to 1:50, 100:1 to 1:50, 1:1 to 1:50, 1000:1 to 1:50, 500:1 to 1:50, 100:1 to 1:50, or 1:1 to 1:50. The feedstock may have a cross sectional ratio of a first dimension to a second dimension (orthogonal to the first dimension) that may be about 2.66:3, 1:2.66, or 1:3.
[0042]The feedstock may have a cross sectional ratio of the first dimension to the second dimension that may be greater than or equal to about 1:50, 1:40, 1:30, 1:20, 1:10, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 10:1, 20:1, 30:1, 40:1, 50:1, 100:1, 200:1, 300:1, 400:1, 500:1, 1000:1, or more. In some example, the first dimension is a width and the second dimension is a height along a given cross-section of the feedstock. The ratio may be greater than or equal to about 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, or more. The ratio may be less than or equal to about 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, or less. The ratio may be from about 10:1 to 1:5, 5:1 to 1:5, 1:1 to 1:5, 1:3 to 1:5, 10:1 to 1:1, 5:1 to 1:1, or 2:1 to 1:1. The ratio may be such that the feedstock may be symmetrical about a given plane. In other instance, the ratio may be such that the feedstock may not be symmetrical about a given plane. The ratio may be such that the feedstock is not tape or tape-like. The ratio may be from about 20:1 to 1:20, or 10:1 to 1:10, or 5:1 to 1:5, or 2:1 to 1:2, or 1.5:1 to 1:1.5. In some examples, a ratio of about 1:1 is for a feedstock with a circular or box-like cross-section.
[0043]During or subsequent to deposition, the deposited feedstock may be compressed or reshaped. This may be performed by applying heat using a non-contact energy source, such as an optical energy source (e.g., laser). The heat may soften, liquefy or melt the polymeric material (e.g., change viscosity). In some instances, amorphous polymers may not have a melting point and can alter in form to a lower viscosity with heat and can be liquids. In other instances, a polymer in solid state may be a super cooled liquid, such as a liquid with very high viscosity. Pressure may be applied to compress deposited layers, which may provide for improved adhesion of layers during formation of the 3D object. The deposition shape may be controlled based at least in part on an original shape of the feedstock, amount of pressure and/or temperature.
[0044]Reshaping of feedstock may have various benefits. For example, this may allow for printing of 3D objects or portions of 3D objects with sharp angles (e.g., 90 degree angles, 180 degree angles, etc.), which may not be possible using tape feedstock. Methods and systems of the present disclosure may permit improved interlayer bonding by applying heat to a previously deposited layer and a layer being deposited. This may provide a liquid-liquid interface, which may enable improved adhesion between layers.
[0045]Interlay bonding may be improved using a combination of materials as part of the feedstock. The feedstock may be a filament material. The filament material may be a composite filament. The feedstock may include one or more polymeric materials and one or more additional fibers. Various examples of the polymeric material are provided elsewhere herein. Such additional fibers may be reinforcing fibers. The one or more additional fibers may include carbon nanotubes, graphene, Bucky balls, metallic materials (e.g., steel), or a combination thereof. For example, the feedstock may incorporate carbon nanotubes and chopped fiber in a polymer matrix. In some cases, the polymer matrix in a composite feedstock may be a thermoplastic or a thermosetting polymer (thermoset).
[0046]The feedstock may comprise one or more polymeric materials and a continuous fiber, long fiber, chopped fiber, milled fiber, nanotube (e.g., carbon nanotube), Bucky Ball, graphene, or a combination thereof. The one or more polymeric materials may be in a polymer matrix. The fiber may be a reinforcing material. Such configuration may improve interlayer bonding. For example, the feedstock comprises a polymeric material and one or more of (i) a continuous fibers, (ii) nanotubes and (iii) chopped fibers. In some examples, the long fiber have lengths from about 30 millimeters (mm) to 100 mm, or 60 mm to 80 mm; the chopped fiber have lengths from about 10 mm to 50 mm, or 20 mm to 30 mm; and the milled fiber have lengths from about 0.5 mm to 5 mm, or 1 mm to 2 mm.
[0047]In some embodiments, the nanotubes may have a length that may be less than or equal to about 1000 nm, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300 nm, 200 nm, 100 nm, 50 nm, 25 nm, 10 nm, 1 nm, 0.1 nm, 0.01 nm, or less. In some embodiments, the nanotubes may have a length that may be greater than or equal to about 0.1 nm, 1 nm, 10 nm, 25 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, or more. In some embodiments, the nanotubes may have a length that may be from about 0.01 nm to 1000 nm, 0.01 nm to 900 nm, 0.01 nm to 800 nm, 0.01 nm to 700 nm, 0.01 nm to 600 nm, 0.01 nm to 500 nm, 0.01 nm to 400 nm, 0.01 nm to 300 nm, 0.01 nm to 200 nm, 0.01 nm to 100 nm, 0.01 nm to 25 nm, 0.01 nm to 10 nm, 0.01 nm to 1 nm, 0.01 nm to 0.1 nm, 1 nm to 1000 nm, 1 nm to 900 nm, 1 nm to 800 nm, 1 nm to 700 nm, 1 nm to 600 nm, 1 nm to 500 nm, 1 nm to 400 nm, 1 nm to 300 nm, 1 nm to 200 nm, 1 nm to 100 nm, 1 nm to 25 nm, 1 nm to 10 nm, 10 nm to 1000 nm, 10 nm to 900 nm, 10 nm to 800 nm, 10 nm to 700 nm, 10 nm to 600 nm, 10 nm to 500 nm, 10 nm to 400 nm, 10 nm to 300 nm, 10 nm to 200 nm, 10 nm to 100 nm, 10 nm to 25 nm, 25 nm to 1000 nm, 25 nm to 900 nm, 25 nm to 800 nm, 25 nm to 700 nm, 25 nm to 600 nm, 25 nm to 500 nm, 25 nm to 400 nm, 25 nm to 300 nm, 25 nm to 200 nm, 25 nm to 100 nm, 50 nm to 1000 nm, 50 nm to 900 nm, 50 nm to 800 nm, 50 nm to 700 nm, 50 nm to 600 nm, 50 nm to 500 nm, 50 nm to 400 nm, 50 nm to 300 nm, 50 nm to 200 nm, 50 nm to 100 nm, 100 nm to 1000 nm, 100 nm to 900 nm, 100 nm to 800 nm, 100 nm to 700 nm, 100 nm to 600 nm, 100 nm to 500 nm, 100 nm to 400 nm, 100 nm to 300 nm, 100 nm to 200 nm, 500 nm to 1000 nm, 500 nm to 900 nm, 500 nm to 800 nm, 500 nm to 700 nm, or 500 nm to 600 nm. In some embodiments, the nanotubes may have a length that may be about 100 nm.
[0048]In some embodiments, the chopped fibers may have a length that may be less than or equal to about 1000 nm, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300 nm, 200 nm, 100 nm, 50 nm, 25 nm, 10 nm, 1 nm, 0.1 nm, 0.01 nm, or less. In some embodiments, the chopped fibers may have a length that may be greater than or equal to about 0.1 nm, 1 nm, 10 nm, 25 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, or more. In some embodiments, the chopped fibers may have a length that may be from about 0.01 nm to 1000 nm, 0.01 nm to 900 nm, 0.01 nm to 800 nm, 0.01 nm to 700 nm, 0.01 nm to 600 nm, 0.01 nm to 500 nm, 0.01 nm to 400 nm, 0.01 nm to 300 nm, 0.01 nm to 200 nm, 0.01 nm to 100 nm, 0.01 nm to 25 nm, 0.01 nm to 10 nm, 0.01 nm to 1 nm, 0.01 nm to 0.1 nm, 1 nm to 1000 nm, 1 nm to 900 nm, 1 nm to 800 nm, 1 nm to 700 nm, 1 nm to 600 nm, 1 nm to 500 nm, 1 nm to 400 nm, 1 nm to 300 nm, 1 nm to 200 nm, 1 nm to 100 nm, 1 nm to 25 nm, 1 nm to 10 nm, 10 nm to 1000 nm, 10 nm to 900 nm, 10 nm to 800 nm, 10 nm to 700 nm, 10 nm to 600 nm, 10 nm to 500 nm, 10 nm to 400 nm, 10 nm to 300 nm, 10 nm to 200 nm, 10 nm to 100 nm, 10 nm to 25 nm, 25 nm to 1000 nm, 25 nm to 900 nm, 25 nm to 800 nm, 25 nm to 700 nm, 25 nm to 600 nm, 25 nm to 500 nm, 25 nm to 400 nm, 25 nm to 300 nm, 25 nm to 200 nm, 25 nm to 100 nm, 50 nm to 1000 nm, 50 nm to 900 nm, 50 nm to 800 nm, 50 nm to 700 nm, 50 nm to 600 nm, 50 nm to 500 nm, 50 nm to 400 nm, 50 nm to 300 nm, 50 nm to 200 nm, 50 nm to 100 nm, 100 nm to 1000 nm, 100 nm to 900 nm, 100 nm to 800 nm, 100 nm to 700 nm, 100 nm to 600 nm, 100 nm to 500 nm, 100 nm to 400 nm, 100 nm to 300 nm, 100 nm to 200 nm, 500 nm to 1000 nm, 500 nm to 900 nm, 500 nm to 800 nm, 500 nm to 700 nm, or 500 nm to 600 nm. In some embodiments, the chopped fibers may have a length that may be about 100 nm.
[0049]The feedstock may be single filament feedstock or multi-filament feedstock. The feedstock may include one or more polymeric materials and one or more reinforcing materials, as described elsewhere herein. A cross-sectional dimension (e.g., diameter in the case of feedstock with circular cross-sections) of the feedstock may be greater than or equal to about 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 10 mm, 20 mm, or more. A cross-sectional dimension (e.g., diameter in the case of feedstock with circular cross-sections) of the feedstock may be less than or equal to about 20 millimeters (mm), about 10 mm, about 5 mm, about 4 mm, about 3 mm, about 2 mm, about 1 mm, about 0.9 mm, about 0.8 mm, about 0.7 mm, about 0.6 mm, about 0.5 mm, about 0.4 mm, about 0.3 mm, about 0.2 mm, about 0.1 mm, or less. The diameter may be from about 0.1 mm to 10 mm, 0.2 mm to 5 mm, 0.3 mm to 4 mm, 0.4 mm to 3 mm, or 0.5 mm to 2 mm.
[0050]The one or more polymeric materials may include a thermoplastic. The one or more polymeric materials may include a thermoset.
[0051]Three-dimensional printing may be performed using various materials. The form of the build materials that may be used in embodiments of the present disclosure include, without limitation, filaments, sheets, powders, and inks. In some examples, a material that may be used in 3D printing includes a polymeric material, elemental metal, metal alloy, a ceramic, composite material, an allotrope of elemental carbon, or a combination thereof. The allotrope of elemental carbon may comprise amorphous carbon, graphite, graphene, diamond, or fullerene. The fullerene may be selected from the group consisting of a spherical, elliptical, linear, tubular fullerene, and any combination thereof. The fullerene may comprise a Bucky ball or a carbon nanotube. The material may comprise an organic material, for example, a polymer or a resin. The material may comprise a solid or a liquid. The material may include one or more strands or filaments. The solid material may comprise powder material. The powder material may be coated by a coating (e.g., organic coating such as the organic material (e.g., plastic coating)). The powder material may comprise sand. The material may be in the form of a powder, wire, pellet, or bead. The material may have one or more layers. The material may comprise at least two materials. In some cases, the material includes a reinforcing material (e.g., that forms a fiber). The reinforcing material may comprise a carbon fiber, Kevlar®, Twaron®, ultra-high-molecular-weight polyethylene, or glass fiber.
[0052]Prior to printing the part or object, a computer aided design (CAD) model may be optimized based on specified requirements. For example, the CAD model may comprise a geometry “envelop”. A geometry envelop may be an initial shell design of the three-dimensional part comprising design requirements and geometric features. The geometry of the CAD model may be received by way of I/O devices. Design requirements may be selected from the group consisting of strength, structural deflections, stress, strain, tension, shear, load capacity, stiffness, factor-of safety, weight, strength to weight ratio, envelop geometry, minimal print time, thermal performance, electrical performance, porosity, infill, number of shells, layer height, printing temperature, print head or nozzle temperature, solid density, melt density, printing speed, print head movement speed, and any combination thereof.
[0053]The CAD model may be initially partitioned according to user input and built in tool path generator rules to produce numerical control programming codes of the partitioned computer model. Partitioning may generate one or more parameters for printing the part. The one or more parameters may be selected from the group consisting of filament diameter, layer thickness, infill percentage, infill pattern, raster angle, build orientation, printed material width, feedstock or deposition material width, layer height, shell number, infill overlap, grid spacing, and any combination thereof. Partitioning may also generate one or more numerical control programming code of the partitioned computer model. The numerical control programming code can comprise G-code files and intermediate files. G-code files may be a numerical control programming language and can be used in computer-aided manufacturing as a way of controlling automated machine tools. The actions controlled by the G-code may comprise rapid movement, controlled feed in an arc or straight line, series of controlled feed movements, switch coordinate systems, and a set of tool information. Intermediate files may comprise supplemental files and tools for a primary build output. Additionally, intermediate files can comprise automatically generated source files or build output from helper tools. The information from the G-code files and the intermediate files may be extracted to determine the geometry of the three-dimensional printed part.
[0054]The 3D object may have a 3D solid model created in CAD software. Such 3D object can be sliced using conventional algorithms as are known in the art to generate a series of two dimensional (2D) or 3D layers representing individual transverse cross sections of the 3D object, which collectively depict the 3D object. The 2D slice information for the layers may be sent to the controller and stored in memory. Such information can control the process of fusing particles into a dense layer according to the modeling and inputs obtained during the build process.
[0055]Prior to printing the three-dimensional object, a model, in computer memory, of the part for three-dimensional printing may be received from a material. The material can comprise a matrix and fiber material. Additionally, in computer memory, one or more properties for the material may be received. Using the model, a print head tool path may be determined for use during the three-dimensional printing of the part. A virtual mesh of analytic elements may be generated within the model of the part and a trajectory of at least one stiffness-contributing portion of the material may be determined based at least in part on the print head tool path, wherein the trajectory of the at least one stiffness-contributing portion may be determined through each of the analytic elements in the virtual mesh. Next, one or more computer processors may be used to determine a performance of the part based at least in part on the one or more properties received and the trajectory of the at least one stiffness-contributing portion. The performance of the part may be electronically outputted. The three-dimensional object may then be printed along the print head tool path.
[0056]The present disclosure may provide ways to improve the mechanical, thermal, and electrical properties of additively manufactured parts. All additive manufacturing approaches build up an object in a layer-by-layer fashion. In other words, the layers of build material are deposited one on top of the next, such that a successive layer of build material may be deposited upon a previously deposited/constructed layer that has cooled below its melting temperature. The print head may comprise three or more axes or degrees of freedom so that the print head can move in the +X direction, the −X direction, the +Y direction, the −Y direction, the +Z direction, the −Z direction, or any combination thereof. The print head may be configured as a six-axis robotic arm. Alternatively, the print head may be configured as a seven-axis robotic arm. The print head may be placed at any location in the build volume of the 3D object, from any approach angle.
[0057]The present disclosure may provide a system for additive manufacturing processes that may provide localized heating to create a “melt pool” in the current layer or segment of deposited build material prior to depositing the next segment or layer. The melt pool may span the entire thickness of the printed segment, thereby increasing the adhesion across segments built in the same layer. The melt pool can span a portion of the thickness of the printed segment. The melt pool may increase the diffusion and mixing of the build material between adjacent layers (across the Z direction) as compared to current methods, which deposit a subsequent layer of build material on top of a layer of build material that may be below its melting temperature. The increased diffusion and mixing resulting from the melt pool can increase the chemical chain linkage/bonding and chemical chain interactions between the two layers. This can result in increases in the build-material adhesion in the Z direction, thereby enhancing mechanical, thermal, and electrical properties. The melt pool may also reduce void space and porosity in the build object. Among any other benefits, this decrease in porosity also contributes somewhat to the aforementioned improvement in mechanical, thermal, and electrical properties. Furth