Abstract: Techniques and compositions are disclosed for composite feedstocks with powder/binder systems suitable for three-dimensional printing, such as fused filament fabrication. The composite feedstocks may include a jacket about a core, with at least the core including a powder material suspended in a binder system and the jacket having a hardness or toughness greater than a hardness or toughness of the core for the feedstock. In general, the harder jacket may protect the core from unintended deformation or damage during transportation, storage, or use. For example, the difference in hardness or toughness between the jacket and the core may facilitate gripping the feedstock (e.g., by gear drives or the like) with a higher amount of force than is otherwise applicable if the feedstock were composed of the core alone, without damaging the core, during a fused filament fabrication process or another additive manufacturing process.

Abstract: A system for de-powdering one or more objects within a powder print bed comprises a build box configured to contain the powder print bed, and a de-powdering subsystem configured to engage the build box. The de-powdering subsystem comprises a vacuum device configured to withdraw loose powder agitated by the air jet device, and a robotic arm configured to convey the vacuum device to one or more locations on the powder print bed. The system may further comprise an air jet device disposed on the robotic arm, the air jet device configured to agitate, with a jet of air, unbound powder within the powder print bed. The system may further comprise a mechanical agitation instrument configured to facilitate agitation of the unbound powder within the powder print bed.

Abstract: A variety of additive manufacturing techniques can be adapted to fabricate a substantially net shape object from a computerized model using materials that can be debound and sintered into a fully dense metallic part or the like. However, during sintering, the net shape will shrink as binder escapes and the base material fuses into a dense final part. If the foundation beneath the object does not shrink in a corresponding fashion, the resulting stresses throughout the object can lead to fracturing, warping, or other physical damage to the object resulting in a failed fabrication. To address this issue, a variety of techniques are disclosed for substrates and build plates that contract in a manner complementary to the object during debinding and sintering.

Abstract: A support structure is fabricated below a printed object to form a structure that prevents or minimizes a drag on a floor while the object shrinks during sintering.

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: 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 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: 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 support structure is formed from a support material below a printed object that shrinks similarly to a build material of the printed object during processing in a furnace.

Abstract: A support structure is fabricated below a printed object to form a structure that prevents or minimizes a drag on a floor while the object shrinks during sintering.

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: 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: A build box associated with a powder bed fabrication system may comprise a housing defining a housing cavity, and a powder print bed disposed within the housing cavity. The powder print bed may be characterized by state information. The build box may further comprise a medium configured to facilitate access to the state information, and a coupling interface for removably engaging the build box with at least one subsystem of the powder bed fabrication system. The state information may comprise one or more state information elements of object identification, object location, current processing state, next subsystem processing step, previous subsystem processing step, object model information, object material composition, and current powder print bed temperature profile. The medium may comprise a memory device coupled with a transceiver. The medium may alternatively comprise an RFID device, or an optically perceivable designator, such as a bar code or QR code.

Abstract: A system for separating objects within a stacked powder print bed of nested objects comprises a build box configured to contain the powder print bed. The build box has a build box top and a build box floor. The system further includes an elongated aperture formed in a side wall of the build box, and a de-powdering subsystem configured to mechanically and electrically engage the build box. A separating blade associated with the de-powdering subsystem is configured to be inserted through the elongated aperture and into the powder print bed between a top-most print bed layer of the nested objects and a second print bed layer directly below and contiguous with the top-most layer, thereby forming an isolated powder print bed between the separating blade and the build box top. The unbound powder may be agitated by various techniques and subsequently removed from the objects.

Abstract: Systems, methods, and apparatus are introduced for controlling an output flow of a build material from an extrusion assembly used for printing a three-dimensional (3D) object. Control of the output flow is based on an input control value that may be a function of a hydraulic capacitance and a hydraulic resistance, representing hydraulic capacitance values and hydraulic resistance values, respectively, associated with the build material, the extrusion assembly, or a combination thereof at one or more locations of the extrusion assembly relative to a melting zone of an extrusion head of the extrusion assembly as well as a target output flow. The input control value enables the output flow to match the target output flow. The hydraulic capacitance and resistance values account for interaction of the build material and a mechanical mechanism of the extrusion assembly driving extrusion of the build material.

Abstract: An additive manufacturing apparatus, and corresponding method, determine a mass (or volume) output flow rate of extrudate used in three-dimensional (3D) printing, and such determination is insensitive to rheological properties of a material of the extrudate being printed. A thermal energy balance on a liquefying extrusion head enables a load on a heater, used to heat the extrusion head, to be related to the output flow rate of extrudate. Based on the thermal energy balance, the output flow rate may be determined based on a duty cycle of the heater. The output flow rate may be employed to affect the 3D printing to prevent over- or under-extrusion of the extrudate and to identify a fault condition.

Abstract: Support structures are used in certain additive fabrication processes to permit fabrication of a greater range of object geometries. For additive fabrication processes with materials that are subsequently sintered into a final part, an interface layer may be fabricated between the object and support in order to inhibit bonding between adjacent surfaces of the support structure and the object during sintering. Interface layers suitable for manufacture with an additive manufacturing system may resist the formation of bonds between a support structure and an object during subsequent sintering processes.

Abstract: Techniques and compositions are disclosed for composite feedstocks with powder/binder systems suitable for three-dimensional printing, such as fused filament fabrication. The composite feedstocks may include a jacket about a core, with at least the core including a powder material suspended in a binder system and the jacket having a hardness or toughness greater than a hardness or toughness of the core for the feedstock. In general, the harder jacket may protect the core from unintended deformation or damage during transportation, storage, or use. For example, the difference in hardness or toughness between the jacket and the core may facilitate gripping the feedstock (e.g., by gear drives or the like) with a higher amount of force than is otherwise applicable if the feedstock were composed of the core alone, without damaging the core, during a fused filament fabrication process or another additive manufacturing process.