Abstract: A method for producing three-dimensional objects layer by layer using a powdery material which can be solidified by irradiating it with at least two electron beams, said method comprises a pre-heating step, wherein the pre-heating step comprises the sub-step of scanning a pre-heating powder layer area (100) by scanning a first electron beam in a first region (I) and by scanning a second electron beam in a second region (II) distributed over the pre-heating powder layer area (100), wherein consecutively scanned paths are separated by, at least, a security distance (?Y), said sub-step further comprising the step of synchronising the preheating of said first and second electron beams when simultaneously preheating said powder material within said first and second regions respectively, so that said first and second electron beams are always separated to each other with at least a minimum security distance (?X).

Abstract: Devices, systems, and methods for monitoring a powder layer in additive manufacturing are disclosed. A method includes receiving leading and trailing image data from an image signal processor that is optically coupled to a plurality of leading and trailing optical fibers arranged on a moving powder distributor, the leading and trailing image data corresponding to images of the powder layer, selecting at least one point on the powder bed that is located within a leading region of interest, determining first characteristics of the point, when the point is located within a trailing region of interest due to movement of the moving powder distributor, determining second characteristics of the point, and comparing the first characteristics to the second characteristics to monitor the powder layer distributed by the moving powder distributor.

Abstract: The present specification relates to an additive manufacturing apparatus comprising an X-ray reference object (18) for calibrating an electron beam unit in the additive manufacturing apparatus by detecting X-rays generated by sweeping an electron beam from the electron beam unit over a reference surface (19) of the X-ray reference object (18) and processing the detected signals, the X-ray reference object (18) comprising a support body (20) that has a top surface (21) and comprises a plurality of holes (22) in the top surface (21), The X-ray reference object (18) comprises a plurality of target members (23) inserted into the plurality of holes (22) of the support body (20). The present specification also relates to an X-ray detector to be used in the additive manufacturing apparatus, and to a method for calibrating such an additive manufacturing apparatus.

Abstract: An apparatus for forming at least one three-dimensional article through successive fusion of parts of a powder bed, which parts corresponds to successive cross sections of the three-dimensional article, the apparatus comprising: a powder distributor configured for evenly distributing a layer of powder on top of a work table provided inside a build chamber; and at least one high energy beam source emanating at least one high energy beam configured for fusing the powder layer in selected locations corresponding to the cross section of the three-dimensional article, wherein the apparatus further comprising at least one target area arranged spaced apart from the layer of powder for emanating light when irradiated by the at least one high energy beam.

Abstract: A method for forming a three-dimensional article through successive fusion of parts of a metal powder bed is provided, comprising the steps of: distributing a first metal powder layer on a work table inside a build chamber, directing at least one high energy beam from at least one high energy beam source over the work table causing the first metal powder layer to fuse in selected locations, distributing a second metal powder layer on the work table, directing at least one high energy beam over the work table causing the second metal powder layer to fuse in selected locations, introducing a first supplementary gas into the build chamber, which first supplementary gas comprising hydrogen, is capable of reacting chemically with or being absorbed by a finished three-dimensional article, and releasing a predefined concentration of the gas which had reacted chemically with or being absorbed by the finished three dimensional article.

Abstract: A blast nozzle for a depowdering apparatus includes an abrasive material inlet fluidly connected to an abrasive material outlet and a fluid inlet fluidly connected to a fluid outlet, where the fluid outlet at least partially surrounds the abrasive material outlet. The fluid outlet is angled with respect to the abrasive material outlet and configured to emit a fluid stream directed to a focal point, the focal point being laterally spaced apart from the blast nozzle in a fluid flow direction.

Abstract: A method for producing three-dimensional objects layer by layer using a powdery material which can be solidified by irradiating it with at least two electron beams, said method comprises a pre-heating step, wherein the pre-heating step comprises the sub-step of scanning a pre-heating powder layer area (100) by scanning a first electron beam in a first region (I) and by scanning a second electron beam in a second region (II) distributed over the pre-heating powder layer area (100), wherein consecutively scanned paths are separated by, at least, a security distance (?Y), said sub-step further comprising the step of synchronising the preheating of said first and second electron beams when simultaneously preheating said powder material within said first and second regions respectively, so that said first and second electron beams are always separated to each other with at least a minimum security distance (?X).

Abstract: A depowdering apparatus for depowdering a cake comprising a build part includes a depowdering chamber, a blast nozzle, and a build elevator. The depowdering chamber includes a bottom surface and a build inlet extending through the bottom surface, where the build inlet includes an inlet axis that is substantially vertically oriented. The blast nozzle is positioned within the depowdering chamber and oriented to direct a fluid stream toward the inlet axis. The blast nozzle is laterally spaced from the inlet axis and operable to revolve about the inlet axis on a travel path encircling the inlet axis. The build elevator is arranged below the build inlet in a vertical direction and is operable to raise the cake comprising the build part through the build inlet and into the depowdering chamber along the inlet axis as the blast nozzle is revolved about the inlet axis on the travel path.

Abstract: Additive manufacturing systems, and methods of encoding and decoding data within a build chamber of an additive manufacturing system are disclosed. An additive manufacturing system includes a build chamber having a patterned surface, the patterned surface having indicia therein or thereon. The additive manufacturing system further includes an energy beam (EB) gun configured to emit an energy beam and a sensor configured to detect one or more x-ray emissions that are generated as a result of impingement of the energy beam on the patterned surface. The one or more x-ray emissions include characteristics that correspond to the indicia such that data encoded in the indicia can be obtained from the characteristics of the one or more x-ray emissions.

Abstract: Described is a build chamber for an additive manufacturing apparatus for forming a three-dimensional article layer by layer from a powder. The build chamber comprises a build chamber base body and said build chamber base body is formed by at least two segments telescopically coupled together.

Abstract: An apparatus for forming at least one three-dimensional article through successive fusion of parts of a powder bed. The apparatus comprises a powder distributor configured for evenly distributing a layer of powder on top of a build table; an energy beam configured for fusing the powder layer in selected locations corresponding to the cross section of the three-dimensional article, the powder distributor comprises an elongated rod provided movable at a predetermined distance above the powder table and with its central axis in parallel with a top surface of the powder table, and a flexible foil attached onto the elongated rod and protruding from the rod towards the powder table; and an elongated device parallel with the powder distributor and arranged onto or over the powder table outside the build table, where the elongated device is arranged for mechanically touching the flexible foil.

Abstract: Disclosed herein are methods for estimating a powder layer thickness in an additive manufacturing machine when forming a three-dimensional article layer by layer. The method comprises applying a first powder layer and selectively melting the first powder layer and thereafter measuring the temperature of the first powder layer at a plurality of times. The method further comprises providing a mathematical function giving a reference temperature as a function of time based on the measured temperatures of the first powder layer, applying a second powder layer on top of the first powder layer and measuring the temperature of the second powder layer at a predetermined time, and estimating the powder layer thickness of the second powder layer based on the measured temperature of the second powder layer and the reference temperature calculated by means of the mathematical function for the predetermined time point.

Abstract: A method for forming at least one three-dimensional article through successive fusion of parts of a powder bed on a support structure, the method comprising the steps of: providing at least one model of the three-dimensional article, lowering the support structure a predetermined distance and rotating the support structure a predetermined angle in a first direction before applying a first powder layer covering the lowered and rotated support structure, rotating the support structure the predetermined angle in a second direction opposite to the first direction before directing the at least one first energy beam from the at least one first energy beam source at selected locations of the first powder layer, the at least one first energy beam source causing the first powder layer on the stationary support structure which is stationary to fuse in the selected locations according to the model to form first portions of the three-dimensional article.

Abstract: An apparatus for forming a three-dimensional article through successively depositing individual layers of powder material that are fused together with an electron beam from an electron beam source so as to form the article according to a computer model thereof. The apparatus includes a chamber a chamber having a first section and a second section openly connected to each other. The first section is configured to receive the individual layers of powder material. The second section comprising an electron beam source, an electromagnetic focus coil having an axially extending, and a reflector coil. The electron beam source is configured to emit an electron beam to fuse the individual layers of powder material. The reflector coil is arranged radially outside the electromagnetic focus coil. The direction of windings of the reflector coil is opposite a direction of windings of the electromagnetic focus coil.

Abstract: Devices, systems, and methods for selectively sintering a powder layer in additive manufacturing processes to achieve a desired heat conductivity are disclosed. A method includes distributing a powder layer in a build chamber, selectively sintering the powder layer to form a plurality of sintered areas and a plurality of non-sintered areas based on a thermal model, and melting a subset of the plurality of sintered areas.

Abstract: A method for controlling an energy beam in an additive manufacturing machine when forming a three-dimensional article layer by layer by successive fusion of selected areas of powder layers, which selected areas correspond to successive layers of the article. The method includes steps of radiating a powder layer by the energy beam and creating a set of images of the powder layer for a set of positions on the powder layer by detecting particles emitted, backscattered or reflected from the powder layer when being radiated, comparing data representing the set of images and reference data with each other for identifying a difference between the energy beam when used on the powder layer and the reference data, with respect to at least one energy beam parameter, and adjusting the energy beam based on such an identified difference between the energy beam when used on the powder layer and the reference data.

Abstract: A device for viewing and/or illuminating a target surface in an evacuated chamber having condensable vapor therein, the device comprising: a first section with a through hole having a first end with a first opening and a second end with a second opening; and a second section having a chamber comprising a first portion with a first opening, a second portion with a second opening and a gas inlet, where the second opening is covered with a first window, said first section is attached with the first end to the first portion of the chamber allowing free passage between the chamber and the first section, said gas inlet is connectable to a gas reservoir for feeding a gas into the chamber for prohibiting the first window in the chamber for being contaminated of the condensable vapor.

Abstract: A method for forming at least one three-dimensional article through successive fusion of parts of a powder bed on a support structure, the method comprising the steps of: providing at least one model of the three-dimensional article, lowering the support structure a predetermined distance and rotating the support structure a predetermined angle in a first direction before applying a first powder layer covering the lowered and rotated support structure, rotating the support structure the predetermined angle in a second direction opposite to the first direction before directing the at least one first energy beam from the at least one first energy beam source at selected locations of the first powder layer, the at least one first energy beam source causing the first powder layer on the stationary support structure which is stationary to fuse in the selected locations according to the model to form first portions of the three-dimensional article.

Abstract: A method for detecting a position of an energy beam comprises mapping a first density modulated x-ray signal with a plurality of locations on an energy beam target, thereby generating a model of a background x-ray intensity. The method further comprises forming an x-ray signal time series using subsequent intensity modulated x-ray signals, each resulting from scanning the energy beam along the energy beam target in one of a plurality of directions at one of a plurality of speeds, and determining the position of the energy beam based upon a received x-ray signal strength based on the x-ray signal time series and the model of the background x-ray intensity.

Abstract: A method for detecting defects in three-dimensional articles. Providing a model of said article. Providing a first powder layer on a substrate, directing an energy beam over said substrate causing said first powder layer to fuse in selected locations forming a first cross section of said three-dimensional article, providing a second powder layer on said substrate, directing the energy beam over said substrate causing said second powder layer to fuse in selected locations to form a second cross section of said three-dimensional article. A first and second image of a first and second fusion zone of said first powder layer respectively is captured. Comparing said first and second images with corresponding layers in said model. Detecting a defect in the three-dimensional article if a deviation in said first image with respect to said model is at least partially overlapping a deviation in said second image with respect to said model.