An apparatus includes a build plate, a powder application apparatus that applies metal powder onto the build plate to form a powder layer, a beam irradiation apparatus that irradiates the powder layer with an electron beam, and a control unit that controls the powder application apparatus and the beam irradiation apparatus. When the powder layer is preheated by irradiation with the electron beam, the control unit sets a beam size and an irradiation position of the electron beam such that lines of the electron beam do not overlap each other at least at a start of preheating, and controls the beam irradiation apparatus to gradually increase at least one of a beam current and the beam size of the electron beam from the start of preheating to an end of preheating.

A print engine of an additive manufacturing system includes a print station configured to hold a removable cartridge containing powder. A laser engine is positioned to direct a one or two dimensional patterned laser beam into the removable cartridge. In some embodiments powder is produced at least in part with a magnetohydrodynamic system.

A print engine of an additive manufacturing system includes a print station configured to hold a removable cartridge containing powder. A laser engine is positioned to direct a one or two dimensional patterned laser beam into the removable cartridge. In some embodiments powder is produced at least in part with a magnetohydrodynamic system.

Methods for repurposing waste materials, such as aluminum powder, are disclosed. A method in accordance with an aspect of the present disclosure may comprise collecting a material in a container, the material comprising oxidized aluminum powder, processing the material, which includes heating the material to melt at least a portion of the oxidized aluminum powder, and forming the processed material into at least one component.

Methods and apparatuses for additive manufacturing are described. A method for additive manufacturing may include exposing a layer of material on a build surface to one or more projections of laser energy including at least one line laser having a substantially linear shape. The intensity of the line laser may be modulated so as to cause fusion of the layer of material according to a desired pattern as the one or more projections of laser energy are scanned across the build surface.

Methods and apparatuses for additive manufacturing are described. A method for additive manufacturing may include exposing a layer of material on a build surface to one or more projections of laser energy including at least one line laser having a substantially linear shape. The intensity of the line laser may be modulated so as to cause fusion of the layer of material according to a desired pattern as the one or more projections of laser energy are scanned across the build surface.

Methods and apparatuses for additive manufacturing are described. A method for additive manufacturing may include exposing a layer of material on a build surface to one or more projections of laser energy including at least one line laser having a substantially linear shape. The intensity of the line laser may be modulated so as to cause fusion of the layer of material according to a desired pattern as the one or more projections of laser energy are scanned across the build surface.

In a three-dimensional printing method example, a liquid functional agent is selectively applied. The liquid functional agent includes an alloying agent. A metallic build material is applied. The liquid functional agent is selectively applied before the metallic build material, after the metallic build material, or both before and after the metallic build material. The liquid functional agent patterns the metallic build material to form a composite layer. At least some of the metallic build material is exposed to energy to melt the at least some of the metallic build material to form a layer. Upon contact or after energy exposure, the alloying agent and the build material alter a composition of the composite layer.

According to one embodiment, a three-dimensional object includes a periodic structure. The periodic structure includes a plurality of unit objects which form a plurality of stepped structures connected to each other. In each of the stepped structures, the unit objects are connected together in a stepwise form along a polygonal spiral trajectory around a unit axis. In each of the stepped structures, the unit axis extends in a first direction. The stepped structures are each provided with a unit channel extending along the connected unit objects of the stepwise form. The periodic structure is provided with a channel in communication with an outside of the periodic structure, the channel including the unit channels.

According to one embodiment, a three-dimensional object includes a periodic structure. The periodic structure includes a plurality of unit objects which form a plurality of stepped structures connected to each other. In each of the stepped structures, the unit objects are connected together in a stepwise form along a polygonal spiral trajectory around a unit axis. In each of the stepped structures, the unit axis extends in a first direction. The stepped structures are each provided with a unit channel extending along the connected unit objects of the stepwise form. The periodic structure is provided with a channel in communication with an outside of the periodic structure, the channel including the unit channels.