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: 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 fabricated between the object and support in order to inhibit bonding between adjacent surfaces of the support structure and the object during sintering. Disclosed herein are interface layers suitable for manufacture with an additive manufacturing system that resist the formation of bonds between a support structure and an object during subsequent sintering processes.

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

Abstract: A three-dimensional printer uses a fused filament fabrication process to fabricate a net shape object from build materials that can be debound and sintered into a final part. In order to facilitate separation of the object from surrounding support structures, the three-dimensional printer is configured to deposit material between adjacent surfaces of the object and the support that inhibit bonding between adjacent surfaces of the support structure and 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 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: 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: 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. Magnets used to form the magnetohydrodynamic forces are thermally managed to facilitate directing strong magnetic fields into liquid metals at high temperatures. Such strong magnetic fields can be useful for imparting, under otherwise equivalent conditions, higher magnetohydrodynamic forces to liquid metal being ejected from a nozzle to form an object.

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: A printer fabricates an object from a computerized model using a fused filament fabrication process and a metallic build material. One or more contact probes may be used to detect a height and/or position of a nozzle, e.g., to zero, center, or otherwise calibrate the nozzle prior to a print, or to determine a height relative to a deposited layer of build material during fabrication.

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: 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. Nozzles associated with these devices, systems, and methods include a combination of materials suitable for withstanding prolonged exposure to high temperatures associated with certain liquid metals while facilitating efficient delivery of current to produce magnetohydrodynamic forces controllable over a range of frequencies associated with commercially viable three-dimensional fabrication.

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. Porosity of one or more predetermined portions of objects fabricated from an accumulation of liquid metal droplets ejected using magnetohydrodynamic force can be controlled to form interfaces between support structures and parts within the object. Higher porosity along the interfaces, as compared to porosity along the support structures and the parts, can be useful for facilitating separation of the parts from the support structures.

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: Devices, systems, and methods are directed to switching between pneumatically actuated ejection and electrically actuated ejection of liquid metal from a nozzle moving along a controlled three-dimensional pattern to fabricate a three-dimensional object. Electrically actuated ejection can be useful, for example, for delivering discrete droplets in areas of the object requiring a high degree of accuracy. Pneumatic ejection can be useful, for example, for delivering a stream of liquid metal from the nozzle to provide liquid metal rapidly to areas of the object that require less accuracy (e.g., an inner portion of the object). Accordingly, switching between pneumatically actuated ejection and electrically actuated ejection can facilitate accurate and rapid production of parts through additive manufacturing.

Abstract: A printer fabricates an object from a build material based on a computerized model and a fused filament fabrication process. A nozzle for depositing the build material has an interior diameter approaching an outer diameter of build material fed to the nozzle in order to reduce extrusion and resistance forces imposed by the nozzle during deposition, while adequately constraining a planar position of the build material for accurate material deposition in a computer-controlled fabrication 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 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 pulsed to reduce the likelihood of formation of an oxidation layer in nozzles associated with these devices, systems, and methods. Such a reduction in the likelihood of formation of an oxidation layer in nozzles can be useful for maintaining integrity of these nozzles between periods of use, such as between formation of parts.

Abstract: A printer fabricates an object from a computerized model using a fused filament fabrication process and a metallic build material. A thermally compatible support structure may be formed to support regions of the object using a dissolvable bulk metallic glass.

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. The magnetohydrodynamic force can be pulsed to eject droplets of the liquid metal to provide control over accuracy of the object being fabricated. The pulsations can be applied in fluid chambers having high resonance frequencies such that droplet ejection can be effectively controlled over a wide range of frequencies, including high frequencies suitable for liquid metal ejection at rates suitable for commercially viable three-dimensional fabrication.