An additive manufacturing system includes one or more light sources and one or more light valves that can be written with two-dimensional gray scale patterns that the light valves impose on beams from the one or more light sources to obtain one or more patterned beams. The one or more patterned beams are steered to each area of a plurality of areas on a layer of powder. The two-dimensional gray scale patterns are selected to achieve desired material properties at each pixel position of the patterned beam incident on the layer of powder. The light valves may modulate one or more of amplitude, phase, or coherence. The material properties may include one or more of Young's modulus, porosity, grain size, and crystalline microstructure.

An example apparatus to produce a three-dimensional object comprises a controller, a build area configured to receive a layer of particulate material, a printhead, and an ultraviolet light emitting diode energy source. The controller is to cause the printhead to deposit a liquid which absorbs ultraviolet radiation onto the layer of particulate material. The controller is further to cause the ultraviolet light emitting diode energy source to irradiate the liquid, after the liquid has been deposited onto the layer of particulate material, thereby to heat the liquid and cause a portion of the particulate material to solidify.

An example apparatus to produce a three-dimensional object comprises a controller, a build area configured to receive a layer of particulate material, a printhead, and an ultraviolet light emitting diode energy source. The controller is to cause the printhead to deposit a liquid which absorbs ultraviolet radiation onto the layer of particulate material. The controller is further to cause the ultraviolet light emitting diode energy source to irradiate the liquid, after the liquid has been deposited onto the layer of particulate material, thereby to heat the liquid and cause a portion of the particulate material to solidify.

An optical module for a machine for machining workpieces and/or for producing molded bodies by way of location-selective solidification of material powder into contiguous regions by a laser beam includes a housing for releasably fastening the optical module to the machine and a collimation optics changer releasably arranged in the housing, having at least two collimation optics which can be moved into a beam path of the laser beam for collimating the laser beam. The collimation optics changer has a mechanism for automatically changing the collimation optics.

An irradiation device for additively manufacturing three-dimensional objects may include a beam generation device configured to generate an energy beam, an optical modulator including a micromirror array disposed downstream from the beam generation device, and a focusing lens assembly disposed downstream from the optical modulator. The micromirror array may include a plurality of micromirror elements configured to reflect a corresponding plurality of beam segment of the energy beam along a beam path incident upon the focusing lens assembly. The focusing lens assembly may include one or more lenses configured to focus the plurality of beam segments such that for respective ones of a plurality of modulation groups including a subset of micromirror elements, a corresponding subset of beam segments are focused to at least partially overlap with one another at a combination zone corresponding to the respective modulation group.

A method for producing a three-dimensional object on a support by applying layer by layer and selectively solidifying a building material in powder form. The method includes lowering the support to a predetermined height below a working plane, applying a layer of the building material in powder form in the working plane, selectively solidifying the applied powder layer at positions corresponding to a cross-section of the object to be produced and repeating the steps of lowering, applying and selectively solidifying until the object is completed. By doing so, the quantity of applied building material in powder form is reduced in a section in an actively controlled way or substantially no building material in powder form is applied in a section in an actively controlled way.

Various embodiments relate to forming particles using undercooled metal particles in response to focused low power laser light. Particle growth can be initiated by utilizing the metastable and liquid nature of the particles, allowing for surface instability promoted by the laser light to induce liquid flow to translate to a neighboring particle. This event can cascade radially leading to accumulation of the liquid metal at the epicenter. The grown solidified particle size can be varied by using different power, exposure time, or working distance. Once the liquid has accumulated into a single region, it eventually solidifies either through homogeneous or heterogeneous nucleation to give a solid particle of larger size than the original. Such a method can be used to print patterns on a surface in four dimensions, where the fourth dimension (4D) is attained through gradient in size of the particles made. Additional systems and methods are disclosed.

A compactor is disclosed for use with an additive manufacturing print head. The compactor may include a housing connectable to the additive manufacturing print head. The compactor may also include a compacting wheel, and at least one spring disposed in the housing and configured to exert an axial force on the compacting wheel. The compactor may further include a piston moveable to adjust a distance between the housing and the compacting wheel.

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.

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.