Abstract: Techniques for depowdering in additive fabrication are provided. According to some aspects, techniques are provided that separate powder from additively fabricated parts through liquid immersion of the parts. Motion of the liquid, such as liquid currents, may dislodge or otherwise move powder away from additively fabricated parts to which it is adhered or otherwise proximate to. The liquid may also provide a vehicle to carry away powder from the additively fabricated parts. Removed powder may be filtered or otherwise separated from the liquid to allow recirculation of the liquid to the parts and/or to enable re-use of the powder in subsequent additive fabrication processes. Techniques for depowdering through liquid immersion may be automated, thereby mitigating challenges associated with manual depowdering operations.

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 is formed between the object and support in order to inhibit bonding between adjacent surfaces of the support structure and the object during sintering.

Abstract: Techniques for depowdering in additive fabrication are provided. According to some aspects, techniques are provided that separate powder from parts by directing gas onto, or near to, the powder. While fragile green parts, such as green parts produced by binder jetting, may be fragile with respect to scraping or impacts, such parts may nonetheless be resistance to damage from directed gas, even if directed at a high pressure. Techniques for depowdering through directed application of gas may be automated, thereby mitigating challenges associated with manual depowdering operations.

Abstract: A method of de-powdering green parts manufactured via binder jetting additive manufacturing. First, a bulk de-powdering operation is conducted on the green part. Next, a fine de-powdering operation is conducted on the green part. The fine de-powdering operation includes disposing the green part within a bed of shot brush de-powdering media and agitating the bed of shot brush de-powdering media to remove from at least one surface of the green part an amount of build material powder.

Abstract: Techniques for depowdering in additive fabrication are provided. According to some aspects, techniques are provided that separate powder from parts through vibration of the powder, the parts, and/or structures mechanically connected to the powder and/or parts. For instance, the application of vibration may dislodge, aerate and/or otherwise increase the flowability of regions of the powder, thereby making it easier to remove the powder with a suitable means. Techniques for depowdering through vibration may be automated, thereby mitigating challenges associated with manual depowdering operations.

Abstract: According to some aspects, techniques are provided for fabricating sinterable metallic parts through the application of directed energy to a build material. In particular, applying energy to a build material comprising a polymer mixed with a metal powder may cause the polymer to form a cohesive structure with the metal powder. As a result, the polymer acts as a “glue” to produce a metallic green part without local melting of the metal. The green part may subsequently be sintered to remove the polymer and produce a fully dense metal part. Optionally, a step of debinding may also be performed prior to, or simultaneously with, sintering.

Abstract: Systems, methods, components, and materials are disclosed for stereolithographic fabrication of three-dimensional, dense objects. A resin including at least one component of a binder system and dispersed particles can be exposed to an activation light source. The activation light source can cure the at least one component of the binder system to form a green object, which can include the at least one component of the binder system and the particles. A dense object can be formed from the green object by removing the at least one component of the binder system in an extraction process and thermally processing particles to coalesce into the dense object.

Abstract: Techniques for depowdering in additive fabrication are provided. According to some aspects, techniques are provided that separate powder from additively fabricated parts through liquid immersion of the parts. Motion of the liquid, such as liquid currents, may dislodge or otherwise move powder away from additively fabricated parts to which it is adhered or otherwise proximate to. The liquid may also provide a vehicle to carry away powder from the additively fabricated parts. Removed powder may be filtered or otherwise separated from the liquid to allow recirculation of the liquid to the parts and/or to enable re-use of the powder in subsequent additive fabrication processes. Techniques for depowdering through liquid immersion may be automated, thereby mitigating challenges associated with manual depowdering operations.

Abstract: According to some aspects, techniques are provided for fabricating sinterable metallic parts through the application of directed energy to a build material. In particular, applying energy to a build material comprising a polymer mixed with a metal powder may cause the polymer to form a cohesive structure with the metal powder. As a result, the polymer acts as a “glue” to produce a metallic green part without local melting of the metal. The green part may subsequently be sintered to remove the polymer and produce a fully dense metal part. Optionally, a step of debinding may also be performed prior to, or simultaneously with, sintering.

Abstract: Techniques are disclosed for fabricating multi-part assemblies. In particular, by forming release layers between features such as bearings or gear teeth, complex mechanical assemblies can be fabricated in a single additive manufacturing process.

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: For conditioning build material for fused filament fabrication, thermal power is both added to and removed from a nozzle in a manner that can reduce sensitivity of the nozzle temperature to fluctuations in build material feed rate. The amount of thermal power added is at least as large as the sum of the amount removed, the amount to condition the material, and losses to the environment. The amount removed may be at least as large as half the thermal power required to condition the material to extrusion temperature, and may be comparable to, or much larger than the conditioning amount. The larger the ratio of the amount removed to the conditioning amount, the less sensitive the nozzle temperature will be to fluctuations in build material feed rate. Fine temperature control arises, enabling building with metal-containing multi-phase materials or other materials that have a narrow working temperature range.

Abstract: A furnace may include an outer wall defining a chamber, the chamber including an internal cavity configured to receive one or more parts, at least one heater positioned within the chamber, the at least one heater being configured to generate temperatures of at least about 800 degrees Celsius within the internal cavity, and a vacuum pump configured to apply a vacuum to at least a portion of the chamber. The furnace may also include at least one layer of inner insulation and at least one layer of outer insulation disposed outward of the inner insulation with respect to the chamber, the at least one layer of outer insulation being sealed with respect to the at least one layer of inner insulation.

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: 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: Techniques for depowdering additively fabricated parts are described. The techniques utilize various mechanisms to separate powder from parts. For instance, techniques for depowdering described herein may include fabrication of auxiliary structures in addition to fabrication of parts. Certain auxiliary structures may aid with depowdering operations, and may be fabricated along with parts during an additive fabrication process. The auxiliary structures may be shaped and/or have positional and/or geometrical relationships to the parts during fabrication. For instance, an auxiliary structure may include a cage structure fabricated around one or more parts.

Abstract: Techniques for depowdering in additive fabrication are provided. According to some aspects, techniques are provided that separate powder from additively fabricated parts through liquid immersion of the parts. Motion of the liquid, such as liquid currents, may dislodge or otherwise move powder away from additively fabricated parts to which it is adhered or otherwise proximate to. The liquid may also provide a vehicle to carry away powder from the additively fabricated parts. Removed powder may be filtered or otherwise separated from the liquid to allow recirculation of the liquid to the parts and/or to enable re-use of the powder in subsequent additive fabrication processes. Techniques for depowdering through liquid immersion may be automated, thereby mitigating challenges associated with manual depowdering operations.

Abstract: Techniques for depowdering in additive fabrication are provided. According to some aspects, techniques are provided that separate powder from parts through vibration of the powder, the parts, and/or structures mechanically connected to the powder and/or parts. For instance, the application of vibration may dislodge, aerate and/or otherwise increase the flowability of regions of the powder, thereby making it easier to remove the powder with a suitable means. Techniques for depowdering through vibration may be automated, thereby mitigating challenges associated with manual depowdering operations.

Abstract: Techniques for depowdering in additive fabrication are provided. According to some aspects, techniques are provided that separate powder from parts by directing gas onto, or near to, the powder. While fragile green parts, such as green parts produced by binder jetting, may be fragile with respect to scraping or impacts, such parts may nonetheless be resistance to damage from directed gas, even if directed at a high pressure. Techniques for depowdering through directed application of gas may be automated, thereby mitigating challenges associated with manual depowdering operations.