An additive manufacturing (AM) system includes a housing defining a chamber, a build platform disposed in the chamber at a first elevation, and a lower gas inlet disposed at a second elevation and configured to supply a lower gas flow. The AM system includes a contoured surface extending between the lower gas inlet and the build platform to direct the lower gas flow from the second elevation at the lower gas inlet to the first elevation at the build platform, where the contoured surface discharges the lower gas flow in a direction substantially parallel to the build platform. The AM system also includes one or more gas delivery devices coupled to the lower gas inlet to regulate one or more flow characteristics of the lower gas flow, and a gas outlet configured to discharge the lower gas flow.

An additive manufacturing (AM) system includes a housing defining a chamber, a build platform disposed in the chamber at a first elevation, and a lower gas inlet disposed at a second elevation and configured to supply a lower gas flow. The AM system includes a contoured surface extending between the lower gas inlet and the build platform to direct the lower gas flow from the second elevation at the lower gas inlet to the first elevation at the build platform, where the contoured surface discharges the lower gas flow in a direction substantially parallel to the build platform. The AM system also includes one or more gas delivery devices coupled to the lower gas inlet to regulate one or more flow characteristics of the lower gas flow, and a gas outlet configured to discharge the lower gas flow.

We describe a method comprising: defining an irradiation section, in particular an irradiation stripe, on a material layer to be irradiated, in an additive layer manufacturing process, with an irradiation beam scanned across the material layer, and defining, within the irradiation section, two or more parallel or substantially parallel scanning vectors for said scanning of a said irradiation beam across the material layer, wherein all scanning vectors within the irradiation section are parallel or substantially parallel with respect to each other, wherein, based on said defining of the two or more parallel or substantially parallel scanning vectors, a line results which connects a first location, on the material layer, of a change in irradiation energy density of a said irradiation beam for a first one of the two or more parallel or substantially parallel scanning vectors and a second location, on the material layer, of a change in irradiation energy density of a said irradiation beam for a second one of the two or more parallel or substantially parallel scanning vectors, wherein the first scanning vector and the second scanning vector are neighboring scanning vectors, wherein a distance between the first location and the second location is smaller than (i) a distance between the first location and a third location of a change in irradiation energy density of a said irradiation beam for the second one of the two or more parallel or substantially parallel scanning vectors and/or (ii) a distance between the second location and a fourth location of a change in irradiation energy density of a said irradiation beam for the first one of the two or more parallel or substantially parallel scanning vectors, and wherein an angle, which differs from 90 degrees (a) irrespectively of a geometry of a workpiece to be produced using the additive layer manufacturing process, and (b) irrespectively of an orientation of the two or more parallel or substantially parallel scanning vectors with respect to an orientation of the irradiation section, is formed (i) between the first scanning vector and the line, and/or (ii) between the second scanning vector and the line.

We describe a method comprising: defining an irradiation section, in particular an irradiation stripe, on a material layer to be irradiated, in an additive layer manufacturing process, with an irradiation beam scanned across the material layer, and defining, within the irradiation section, two or more parallel or substantially parallel scanning vectors for said scanning of a said irradiation beam across the material layer, wherein all scanning vectors within the irradiation section are parallel or substantially parallel with respect to each other, wherein, based on said defining of the two or more parallel or substantially parallel scanning vectors, a line results which connects a first location, on the material layer, of a change in irradiation energy density of a said irradiation beam for a first one of the two or more parallel or substantially parallel scanning vectors and a second location, on the material layer, of a change in irradiation energy density of a said irradiation beam for a second one of the two or more parallel or substantially parallel scanning vectors, wherein the first scanning vector and the second scanning vector are neighboring scanning vectors, wherein a distance between the first location and the second location is smaller than (i) a distance between the first location and a third location of a change in irradiation energy density of a said irradiation beam for the second one of the two or more parallel or substantially parallel scanning vectors and/or (ii) a distance between the second location and a fourth location of a change in irradiation energy density of a said irradiation beam for the first one of the two or more parallel or substantially parallel scanning vectors, and wherein an angle, which differs from 90 degrees (a) irrespectively of a geometry of a workpiece to be produced using the additive layer manufacturing process, and (b) irrespectively of an orientation of the two or more parallel or substantially parallel scanning vectors with respect to an orientation of the irradiation section, is formed (i) between the first scanning vector and the line, and/or (ii) between the second scanning vector and the line.

Systems and methods that prevent oxygen inhibition of a light-initiated polymerization reaction by forcing the oxygen away from the reaction surfaces. In some embodiments, oxygen is purged by bringing a planarizing surface (e.g., a thin transparent film and/or a transparent planar surface) into contact with a layer of UV curable material disposed on a workpiece and then moving the planarizing surface away from the workpiece one the UV material is cured.

Systems and methods that prevent oxygen inhibition of a light-initiated polymerization reaction by forcing the oxygen away from the reaction surfaces. In some embodiments, oxygen is purged by bringing a planarizing surface (e.g., a thin transparent film and/or a transparent planar surface) into contact with a layer of UV curable material disposed on a workpiece and then moving the planarizing surface away from the workpiece one the UV material is cured.

A lamination molding apparatus which can improve the lamination molding accuracy, is provided. A lamination molding apparatus, including a chamber covering a desired molding region, the chamber being filled with an inert gas of a predetermined concentration; and a molding table provided in the molding region, the molding table being configured so as to be capable of being moved vertically by a driving mechanism; wherein the molding table is configured to be temperature-controllable; and a thermostatic section is provided in between the molding table and the driving mechanism or in the driving mechanism, temperature of the thermostatic section being maintained substantially constant, is provided.

Described herein are compositions, methods, and systems for printing metal three-dimensional objects. In an example, described is a composition for three-dimensional printing comprising: a metal powder build material, wherein the metal powder build material has an average particle size of from about 10 μm to about 250 μm; and a binder fluid comprising: an aqueous liquid vehicle, and latex polymer particles dispersed in the aqueous liquid vehicle, wherein the latex polymer particles have an average particle size of from about 10 nm to about 300 nm.

A method for real-time surface imperfection detection for additive manufacturing and 3-D printing parts is provided. The method includes directing a first light radiation using one or more illumination sources, wherein the first light radiation illuminates a target area of a part being manufactured in a uniform chromatic light such that the target area appears to have a substantially uniform monochromatic color; capturing a current image of a second light radiation that is scattered or reflected by the target area using one or more feedback cameras; and analyzing the current image of the second light radiation using at least one of the one or more feedback camera with a previously acquired image to determine whether a surface imperfection exists or does not exist.

A method for real-time surface imperfection detection for additive manufacturing and 3-D printing parts is provided. The method includes directing a first light radiation using one or more illumination sources, wherein the first light radiation illuminates a target area of a part being manufactured in a uniform chromatic light such that the target area appears to have a substantially uniform monochromatic color; capturing a current image of a second light radiation that is scattered or reflected by the target area using one or more feedback cameras; and analyzing the current image of the second light radiation using at least one of the one or more feedback camera with a previously acquired image to determine whether a surface imperfection exists or does not exist.