Abstract: An apparatus, and corresponding method, feeds build material, in the form of rods, to a drive system in a three-dimensional (3D) printing system. The apparatus dispenses a rod to a media tray and into a first groove defined by a flipper arm. The flipper arm is in a substantially horizontal position supported by a bottom ridge of the media tray. The flipper arm is rotated away from the bottom ridge and toward a stopper coupled to the flipper arm and the media tray. The stopper defines a second groove. The apparatus deposits the rod into the drive system via a feed shaft formed by the first and second grooves of the flipper arm and stopper, respectively. The apparatus enables high-speed 3D printing using the rods by overcoming challenges in loading the rods due to brittleness of the rods.

Abstract: An improved additive manufacturing system for manufacturing metal parts by magnetohydrodynamic printing liquid metal. A monitoring system including at least one camera capturing light reflected from a strobe light source. Images of the droplets are captured during their jetting and analyzed to determine whether the jetting performance is meeting specifications. A nozzle of the system has a nozzle bottom and a nozzle stem extending outward therefrom on which a meniscus of liquid metal can form. The nozzle is cleaned by bringing a ceramic rod in the vicinity of the nozzle and jetting a bead of metal which is rotated against the nozzle to remove an amount of dross.

Abstract: A camera assembly is employed in additive manufacturing to improve the fidelity of a printed object. The camera may scan the surface of a build plate of a 3D printer and an object as it is being printed to generate image data. The image data is processed to detect errors in the build plate or printed object. The printer compensates for the detected errors, which can including modifying the printer configuration and/or modifying the instructions for printing a given object. Using the updated configuration, subsequent objects may then be printed, under a corrected process, to produce an object with fidelity to an original object model.

Abstract: Methods and systems are disclosed for generatively designing a model of an assembly of mechanical parts. One method includes receiving a first set of constraints for a first part; determining a spatial relationship between the first part and a second part; updating the first set of constraints for the first part based on at least the spatial relationship between the first part and the second part; updating a second set of constraints for the second part based on at least the updated first set up constraints and/or the spatial relationship between the first part and the second part; and generating a model for the first part based on the updated first set of constraints.

Abstract: The devices, systems, and methods of the present disclosure are directed to spreader positioning techniques for consistent and rapid layer-by-layer fabrication of three-dimensional objects formed through binder jetting. For example, an additive manufacturing system may include a roller and a print carriage. In a layer-by-layer fabrication process, the roller may move in advance of the print carriage over a dimension of a volume to spread a respective layer of powder onto which the print carriage delivers a binder. Controlling the position of the roller may facilitate achieving consistent layer characteristics which, in turn, may facilitate fabrication of high quality parts.

Abstract: A method of additive manufacturing using magnetohydrodynamic (MHD) printing of liquid metal. A first current pulse is applied to a liquid metal in a nozzle to eject a droplet from a discharge orifice. A second current pulse is applied to the liquid metal in the nozzle to reduce an amplitude of the oscillations in a meniscus on the discharge orifice. The second current pulse can be either of an opposite or the same polarity as the first current pulse and is timed according to according to the oscillation.

Abstract: An actuation method comprising applying a force to a first rod of build material disposed within an actuation volume. The first rod of build material may include at least one metal. The method may further comprise moving the first rod of build material in a direction substantially parallel to or substantially coaxial with a longitudinal axis of the first rod of build material toward an extrusion head and loading a second rod of build material into the actuation volume. The second rod of build material may include at least one metal. A longitudinal axis of the second rod may be substantially coaxial with the longitudinal axis of the first rod. The applying step and the moving step may be repeated for the second rod of build material.

Abstract: Devices, systems, and methods are directed to binder jetting for forming three-dimensional parts having controlled, macroscopically inhomogeneous material composition. In general, a binder may be delivered to each layer of a plurality of layers of a powder of inorganic particles. An active component may be introduced, in a spatially controlled distribution, to at least one of the plurality of layers such that the binder, the powder of inorganic particles, and the active component, in combination, form an object. The object may be thermally processed into a three-dimensional part having a gradient of one or more physicochemical properties of a material at least partially formed from thermally processing the inorganic particles and the active component of the object.

Abstract: Devices, systems, and methods are directed at spreading sequential layers of powder across a powder bed and applying energy to each layer to form a three-dimensional object. The powder can include granules including agglomerations of metallic particles to facilitate spreading the metallic particles in each layer. The energy can be directed to the powder to reflow the granules in each layer to bind the metallic particles in the layer to one another and to one or more adjacent layers to form the three-dimensional object. Thus, in general, the agglomeration of the metallic particles in the granules can overcome constraints associated with metallic particles that are of a size ordinarily unsuitable for flowing and/or a size that presents safety risks. By overcoming these constraints, the granules can improve formation of dense finished parts from a powder and can result in formation of unique microstructures in finished parts.

Abstract: A method of developing a frequency map for an MHD jetting nozzle includes filling the MHD jetting nozzle with a liquid metal. The MHD jetting nozzle is excited with a series of jetting pulses delivered at a range of frequencies the vibration response of the MHD jetting nozzle and/or a meniscus of jetting material is measured.

Abstract: A nozzle assembly for metal additive manufacturing using magnetohydrodynamic jetting. A nozzle defines a reservoir and a discharge region having a discharge orifice. A thick film heating system disposed on an exterior of the nozzle and including a first contact pad and a second contact pad connected by a heating pathway heats build material in the nozzle to a liquid state. A first electrode and a second electrode together configured to deliver an electrical current through the liquid build material in the discharge region while a magnet system delivers a magnetic field perpendicular the electrical current, thereby jetting liquid metal to form successive build layers.

Abstract: Mold lock is remediated by performing a layer-by-layer, two-dimensional analysis to identify unconstrained removal paths for any support structure or material within each two-dimensional layer, and then ensuring that aligned draw paths are present for all adjacent layers, all as more specifically described herein. Where locking conditions are identified, a sequence of modification rules are then applied, such as by breaking support structures into multiple, independently removable pieces. By addressing mold lock as a series of interrelated two-dimensional geometric problems, and reserving three-dimensional remediation strategies for more challenging, complex mold lock conditions, substantial advantages can accrue in terms of computational speed and efficiency.

Abstract: An apparatus, and corresponding method, feeds build material, in the form of rods, to a drive system in a three-dimensional (3D) printing system. The apparatus dispenses a rod to a media tray and into a first groove defined by a flipper arm. The flipper arm is in a substantially horizontal position supported by a bottom ridge of the media tray. The flipper arm is rotated away from the bottom ridge and toward a stopper coupled to the flipper arm and the media tray. The stopper defines a second groove. The apparatus deposits the rod into the drive system via a feed shaft formed by the first and second grooves of the flipper arm and stopper, respectively. The apparatus enables high-speed 3D printing using the rods by overcoming challenges in loading the rods due to brittleness of the rods.

Abstract: A method for fabricating an infiltrated object of a desired shape having a high volume fraction of infiltrant using an additively manufactured preform. Using an additive manufacturing technique, the preform is formed with graded macro-porosity. When infiltrated, the void volume of the macro-porosity is filled with infiltrant Optionally, the void volume may be varied across the profile of the object to create a gradient of mechanical properties in the infiltrated object.

Abstract: The devices, systems, and methods of the present disclosure are directed to powder spreading and binder distribution techniques for consistent and rapid layer-by-layer fabrication of three-dimensional objects formed through binder jetting. For example, a powder may be spread to form a layer along a volume defined by a powder box, a binder may be deposited along the layer to form a layer of a three-dimensional object, and the direction of spreading the layer and depositing the binder may be in a first direction and in a second direction, different from the first direction, thus facilitating rapid formation of the three-dimensional object with each passage of the print carriage over the volume. Powder delivery, powder spreading, thermal energy delivery, and combinations thereof, may facilitate consistently achieving quality standards as the rate of fabrication of the three-dimensional object is increased.

Abstract: Techniques and compositions are disclosed for three-dimensional printing with powder/binder systems including, but not limited to, metal injection molding powder materials, highly-filled polymer composites, and any other materials suitable for handling with various additive manufacturing techniques, and further suitable for subsequent debinding and thermal processing into a final object.

Abstract: A camera assembly is employed in additive manufacturing to improve the fidelity of a printed object. The camera may scan the surface of a build plate of a 3D printer and an object as it is being printed to generate image data. The image data is processed to detect errors in the build plate or printed object. The printer compensates for the detected errors, which can including modifying the printer configuration and/or modifying the instructions for printing a given object. Using the updated configuration, subsequent objects may then be printed, under a corrected process, to produce an object with fidelity to an original object model.

Abstract: Devices, systems, and methods are directed to the use of nanoparticles for improving strength fabrication of three-dimensional objects formed through layer-by-layer process in which an ink is delivery of a binder delivered onto successive layers of a powder of inorganic particles in a powder bed. More specifically, nanoparticles of inorganic material can may be introduced into one or more layers of the metal powder in the powder bed and thermally processed to facilitate sinter necking, in the powder bed, of the metal particles forming the three-dimensional object. Such sinter necking in the powder bed can may improve strength of the three-dimensional objects being fabricated and, also or instead, can may reduce the likelihood of defects associated with subsequent processing of the three-dimensional objects (e.g., slumping and shrinking in a final sintering stage and/or inadequate densification of the final part).

Abstract: Devices, systems, and methods are directed to coated powder for three dimensional additive manufacturing. The powder may include a first material coated with a second material, with the coating advantageously resisting segregation of the first material and the second material during handling processes associated with fabrication. The reduced segregation of the first material and the second material may facilitate forming finished three-dimensional parts with improved homogeneity of microstructures and, thus, improved physicochemical properties. More generally, the reduced segregation of the first material and the second material achievable through coating the first material with the second material may facilitate binder jet fabrication using a wider array of combinations of first material and second material as compared to binder jet fabrication using mixtures of constituent powders of the first material and the second material.

Abstract: Techniques for debinding additively fabricated parts are described that do not require solvent debinding or catalytic debinding, and that may be performed using only thermal debinding in a furnace. As a result, in at least some cases debinding and sintering may take place sequentially within a single furnace. In some embodiments, the techniques may utilize particular materials as binders that allow for a thermal debinding process that does not negatively affect the parts.