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: 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.

Abstract: Disclosed is a method for manufacturing three-dimensional articles with porosity.

Abstract: Various embodiments of the present invention relate to a method of using of a focus lens in additive manufacturing for forming a three-dimensional article through successive fusion, with a high energy beam, of parts of at least one layer of a powder bed provided on a work table, which parts correspond to successive cross sections of the three dimensional article, said method comprising the step of: using said focus lens for varying a spot size of said high energy beam on said powder bed as a function of an already fused thickness of said three-dimensional article below said powder which is to be fused. The invention is also related to a method for forming a three dimensional article.

Abstract: Provided is an additive manufacturing apparatus for additive manufacturing of three dimensional objects by selectively solidifying a powder material layer by layer in a process chamber, wherein the apparatus comprises a powder distributor movable across a build area of a build tank for applying a layer of powder material thereon and a solidification device for selectively solidifying the applied powder layer at positions corresponding to a cross section of the object to be manufactured and a control unit adapted to repeat the steps of applying and selectively solidifying until the object is completed, wherein at least one support structure for supporting the powder distributor and/or a bellows assembly associated there-with is connectable to a cooling/heating media supply outside the process chamber and the support structure and/or the bellows assembly is adapted for transporting the cooling/heating media to and from the powder distributor.

Abstract: Various embodiments of the present invention relate to a method for welding a workpiece comprising the steps of: making a first weld at a first position on said workpiece with a high energy beam, deflecting the high energy beam with at least one deflection lens for making a second weld at a second position on said workpiece, focusing the high energy beam on said workpiece with at least one focusing lens, shaping the high energy beam on said workpiece with at least one astigmatism lens so that the shape of the high energy beam on said workpiece is longer in a direction parallel to a deflection direction of said high energy beam than in a direction perpendicular to said deflection direction of said high energy beam. The invention is also related to the use of an astigmatism lens and to a method for forming a three dimensional article.

Abstract: The invention relates to a platform device (4) for forming a three-dimensional article (2) in an additive manufacturing machine layer by layer by successive fusion of selected areas of powder layers (3), which selected areas correspond to successive layers of the three-dimensional article. The platform device (4) has a support member (5) with a surface (6) for receiving powder. The support member (5) is rotatable about a first rotation axis (13) extending in a direction (15) substantially perpendicular to the surface (6). The support member (5) and the first rotation axis (13) are rotatable about a second rotation axis (14) arranged substantially in parallel with and off-set to the first rotation axis (13).

Abstract: The present invention relates to an apparatus for forming a three-dimensional article through successively depositing individual layers of powder material that are fused together so as to form the article, the apparatus comprising an electron beam source emanating an electron beam for fusing the powder material in a build tank, a hollow construction having an upper opening and a lower opening, means for moving the hollow construction between a first position and a second position, a synchronising unit for synchronising the movement of a powder distributor for applying the individual layers of powder material on the work table with the movement of the hollow construction so that the hollow metal construction is at the first position when fusing and/or heating the powder layer and at the second position when the powder distributor is distributing the powder material for forming the individual powder layers.

Abstract: An additive manufacturing apparatus includes a process chamber housing with a process chamber. A powder storage vessel is in the process chamber. The powder storage vessel includes a vessel body including a powder storage volume, a floor including a powder delivery opening extending therethrough and a bottom cap including a powder delivery opening extending therethrough. In an open configuration, the powder delivery opening of the bottom cap is aligned with the powder delivery opening of the floor to allow powder material to flow from the powder storage vessel through the powder delivery openings. In a closed configuration, one or both of the vessel body and the bottom cap is rotated relative to the other to misalign the powder delivery openings and inhibit powder material from flowing from the powder storage vessel through the powder delivery openings.

Abstract: An additive manufacturing apparatus includes a process chamber housing enclosing a process chamber. The process chamber housing includes a first separable process chamber housing portion and a second separable process chamber housing portion. The first separable process chamber housing portion includes a top of the process chamber housing and the second separable process chamber housing portion includes a bottom of the process chamber housing. The first separable process chamber housing portion meets the second separable process chamber housing portion at a junction that extends about a periphery of the process chamber housing portion in a closed configuration. The process chamber housing has an open configuration where the first separable process housing portion and the second separable process housing portion are separated to provide an access spacing between the first separable housing portion and the second separable housing portion.

Abstract: An additive manufacturing apparatus for forming a three-dimensional article through successive fusion of parts of layers of a powder material, which parts correspond to successive cross-sections of the three-dimensional article includes a process chamber housing enclosing a process chamber. A rotatable support conveyor is rotatably connected to a bottom of the process chamber housing by a rotatable shaft. The rotatable support conveyor includes an opening that extends therethrough for dispensing powder material from a powder storage vessel located on the rotatable support conveyor and a powder distributor that includes a rake portion that is located between the rotatable support conveyor and the bottom of the process chamber housing.

Abstract: Various embodiments of the present invention relate to a method of using of a focus lens in additive manufacturing for forming a three-dimensional article through successive fusion, with a high energy beam, of parts of at least one layer of a powder bed provided on a work table, which parts correspond to successive cross sections of the three dimensional article, said method comprising the step of: using said focus lens for varying a spot size of said high energy beam on said powder bed as a function of an already fused thickness of said three-dimensional article below said powder which is to be fused. The invention is also related to a method for forming a three dimensional article.

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: A method is provided for forming a three-dimensional article through successively depositing individual layers of powder material that are fused together so as to form the article. The method includes: providing at least one electron beam source emitting an electron beam; providing a leakage current detector for sensing a current through the anode and/or the Wehnelt cup; providing a low impedance voltage source connectable to the Wehnelt cup via a switch, where the voltage source is having a more negative potential than a negative potential applied to the cathode; and protecting the cathode against vacuum arc discharge energy currents when forming the three-dimensional article by providing the Wehnelt cup to the low impedance negative voltage by closing the switch when the leakage current detector is sensing a current through the anode and/or the Wehnelt cup which is higher than a predetermined value.