Abstract: A printer fabricates an object from a computerized model using a fused filament fabrication process. The shape of an extrusion nozzle may be varied during extrusion to control, e.g., an amount of build material deposited, a shape of extrudate exiting the nozzle, a feature resolution, and the like.

Abstract: The devices, systems, and methods of the present disclosure are directed to thermal energy delivery to facilitate rapid layer-by-layer fabrication of three-dimensional objects formed through binder jetting. More specifically, 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. Thermal energy may be delivered to each layer in the first and second directions to dry or otherwise change the binder and/or the powder to reduce the likelihood of distorting the binder in a given layer as a subsequent layer is rapidly formed over the given layer.

Abstract: A printer fabricates an object from a computerized model using a fused filament fabrication process. A former extending from a nozzle of the printer supplements a layer fusion process by applying a normal force on new material as it is deposited to form the object. The former may use a variety of techniques such as heat and rolling to improve physical bonding between layers.

Abstract: A printer fabricates an object from a computerized model using a fused filament fabrication process. The shape of an extrusion nozzle may be varied during extrusion to control, e.g., an amount of build material deposited, a shape of extrudate exiting the nozzle, a feature resolution, and the like.

Abstract: The devices, systems, and methods of the present disclosure are directed to dispensing powder for rapid and accurate layer-by-layer fabrication of three-dimensional objects formed through binder jetting. More specifically, a powder may be dispensed from a hopper movable over a volume defined by a powder box to facilitate, for example, rapidly delivering powder in front of a spreader movable across the volume to spread the powder into a layer. The hopper may include a plurality of dispensing rollers along a dispensing region of the hopper. The dispensing rollers may be rotatable relative to one another to control dispensing the powder from the hopper to an area in front of the spreader, reducing wasted motion associated with moving a spreader to retrieve powder from a stationary powder supply and reducing the likelihood of inadvertently delivering powder from the hopper to unintended areas.

Abstract: The devices, systems, and methods of the present disclosure are directed to spreading powder to facilitate accurate layer-by-layer fabrication of three-dimensional objects formed through binder jetting. More specifically, a spreader may be moved across a volume defined by a powder box to spread the powder in a layer. As the spreader is moved across the volume, the spreader may vibrate to pack the powder in the volume. By applying this vibration to the powder on a layer-by-layer basis, the resulting three-dimensional object formed through the binder jetting process may have improved density. In turn, such improved density may be useful for forming the three-dimensional objects into finished parts meeting target density standards, which may be particularly useful in the fabrication of metal parts. Further, or instead, applying vibration to the powder may reduce the likelihood of layer-to-layer variations in the three-dimensional object, thus reducing the likelihood of defects in finished parts.

Abstract: Devices, systems, and methods are directed to the use of nanoparticles for improving fabrication of three-dimensional objects formed through layer-by-layer delivery of an ink onto a powder of metal particles in a powder bed. More specifically, the ink may include high aspect ratio nanoparticles, such as filaments. As compared to nanoparticles having lower aspect ratios, high aspect ratio nanoparticles may facilitate bridging more surface of the metal particles in the powder bed. As the three-dimensional objects including the high aspect ratio nanoparticles and the metal particles are thermally processed, the increased bridging associated with the high aspect ratio nanoparticles may result in increased bonded area between the nanoparticles and the metal particles and, thus, three-dimensional objects that are more robust with respect to subsequent processing required to form the three-dimensional objects into finished parts.

Abstract: Devices, systems, and methods are directed to the use of nanoparticles for improving fabrication of three-dimensional objects formed through layer-by-layer delivery of an ink onto a powder of metal particles in a powder bed. More specifically, the ink may include ceramic nanoparticles that may be maintained in a stable form, providing a shelf-life suitable for transportation and storage of the ink in large-scale commercial operations. The ink may be delivered onto the powder of the metal particles in the powder bed, where the ceramic nanoparticles may interact with the metal particles to improve strength of the three-dimensional objects being fabricated. Also, or instead, the nanoparticles may reduce the likelihood of defects associated with subsequent processing of the three-dimensional objects (e.g., slumping and shrinking and/or inadequate densification of the final part).

Abstract: A powder bed is filled layer by layer with a powdered build material containing an activatable binder. The binder in each new layer is locally activated according to a computerized three-dimensional model of an object to fabricate, layer by layer, a sinterable net shape of the object within the powder bed. The sinterable net shape can then be removed, debound as appropriate, and sintered into a final part.

Abstract: Binder jetting techniques can be used to deposit and bind metallic particles or the like in a net shape for debinding and sintering into a final part. Where support structures are required to mitigate deformation of the object during the debinding and/or sintering, an interface layer may be formed between the support structures and portions of the object in order to avoid bonding of the support structure to the object during sintering.

Abstract: Binder jetting techniques can be used to deposit and bind metallic particles or the like in a net shape for debinding and sintering into a final part. Where support structures are required to mitigate deformation of the object during the debinding and/or sintering, an interface layer may be formed between the support structures and portions of the object in order to avoid bonding of the support structure to the object during sintering.

Abstract: A powder bed is filled layer by layer with a sinterable powder and a liquid binder. After the liquid binder is applied, the liquid binder can be activated, e.g., by selectively curing cross-sections of the binder according to a computerized three-dimensional model of an object. In this manner, a sinterable net shape object can be formed within the powder bed layer by layer. The sinterable net shape can then be removed, debound as appropriate, and sintered into a final part.

Abstract: A printer fabricates an object from a computerized model using a fused filament fabrication process and a metallic build material. The Seebeck effect can be employed to monitor a temperature difference between a build material and a nozzle that is extruding the build material based on voltage. The temperature difference can, in turn, be used to control operation of the printer or to determine an absolute temperature based on direct measurement of a temperature of the nozzle.

Abstract: A printer fabricates an object from a computerized model using a fused filament fabrication process and a metallic build material. A plasma depassivation wash is applied during deposition to remove oxidation and improve interlayer bonding between successive layers of the metallic build material. Other techniques such as ultrasonic vibration, formation of energy directors, joule heating, and the like, may be used in combination to form a mechanically robust bond between layers.

Abstract: A control loop for extrusion of a metallic build material such as bulk metallic glass measures a force required to extrude the build material, and uses this sensed parameter to estimate a temperature of the build material. The temperature, or a difference between the estimated temperature and a target temperature, can be used to speed or slow extrusion of the build material to control heat transfer from a heating system along the feedpath. This general control loop may be modified to account for other possible conditions such as nozzle clogging or the onset of crystallization.

Abstract: A class of metallic composites is described with advantageous bulk properties for additive fabrication. In particular, the composites described herein can be used in fused filament fabrication or any other extrusion or deposition-based three-dimensional printing process.

Abstract: Devices, systems, and methods are directed to applying magnetohydrodynamic forces to liquid metal to eject liquid metal along a controlled pattern, such as a controlled three-dimensional pattern as part of additive manufacturing of an object. An electric current delivered to produce the magnetohydrodynamic forces can be controlled between a pulsed electric current and a direct electric current to change the rate of liquid metal ejection from a nozzle. For example, the electric current can be switched between a pulsed electric current and a direct electric current based at least in part on a position of the nozzle along the controlled pattern, providing accuracy of liquid metal deposition along portions of the pattern having more detail and providing speed of liquid metal deposition along portions of the pattern having less detail.

Abstract: Devices, systems, and methods are directed to applying magnetohydrodynamic forces to liquid metal to eject liquid metal from a nozzle along a controlled pattern, such as a controlled three-dimensional pattern as part of additive manufacturing of an object. A feeder system can provide a continuous or substantially continuous supply of a solid metal to the nozzle to facilitate a correspondingly continuous or substantially continuous process for ejecting liquid metal as part of a commercially viable manufacturing process.

Abstract: Devices, systems, and methods are directed to applying magnetohydrodynamic forces to liquid metal to eject liquid metal along a controlled pattern, such as a controlled three-dimensional pattern as part of additive manufacturing of an object. Electric current delivered to a meniscus of the liquid metal in a quiescent state can be directed to exert a pullback force on the liquid metal. The pullback force can be sufficient to draw the liquid metal, in the quiescent state, in a direction toward the nozzle to reduce the likelihood of unintended wetting of surfaces of the nozzle between uses of the nozzle.

Abstract: A printer fabricates an object from a computerized model using a fused filament fabrication process and a build material. One or more energy directors such as ridges are formed in an exposed surface of the deposited build material to provide regions of high, localized contact force that can improve interlayer bonding between successive layers of the build material. An ultrasonic vibrator can also usefully be incorporated into the printer to apply additional energy along these energy directors during deposition of a subsequent layer.