Abstract: The present invention relates to a method for prolonging lifetime of a triod electron beam source when 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 comprising the steps of: adjusting a cathode heating power at a predetermined value above a threshold heating value, which threshold heating value creates a predetermined X-ray signal emanating from the triod electron beam source, fusing the three-dimensional article with the electron beam source having the cathode heating power at a predetermined value above a threshold heating value.

Abstract: A method for detecting electron beam filament wear in an electron beam source, the method comprising the steps of: enlarging a beam spot emanating from the electron beam source on a work table to a predetermined minimum size, capturing an image of the beam spot on the work table by a camera, comparing the captured image of the beam spot with a reference image, and detecting filament wear if the captured image is deviating more than a predetermined value from the reference image.

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 comprising the steps of: providing at least one electron beam source emitting an electron beam for at least one of heating or fusing the powder material, where the electron beam source comprises a cathode, an anode, and a Wehnelt cup between the cathode and anode; providing a guard ring between the Wehnelt cup and the anode and in close proximity to the Wehnelt cup, where the guard ring is having an aperture which is larger than an aperture of the Wehnelt cup; protecting the cathode and/or the Wehnelt cup against vacuum arc discharge energy currents when forming the three-dimensional article by providing the guard ring with a higher negative potential than the Wehnelt cup and cathode.

Abstract: A method for forming a three-dimensional article through successive fusion of parts of a powder bed comprising: providing a model of the three dimensional article, applying a first powder layer on a work table, directing an energy beam over the work table causing the first powder layer to fuse in selected locations according to the model to form a first cross section of the three-dimensional article, applying a second powder layer on the work table, directing the energy beam over the work table causing the second powder layer to fuse in selected locations according to the model to form a second cross section of the three-dimensional article, wherein the second layer is bonded to the first layer, detecting a local thickness in at least two positions in at least the second powder layer, varying an energy beam parameter depending on the detected local thickness of the second powder layer.

Abstract: A method for forming a three-dimensional article through successive fusion of parts of a powder bed comprising: providing a model of the three dimensional article, applying a first powder layer on a work table, directing an energy beam over the work table causing the first powder layer to fuse in selected locations according to the model to form a first cross section of the three-dimensional article, applying a second powder layer on the work table, directing the energy beam over the work table causing the second powder layer to fuse in selected locations according to the model to form a second cross section of the three-dimensional article, wherein the second layer is bonded to the first layer, detecting a local thickness in at least two positions in at least the second powder layer, varying an energy beam parameter depending on the detected local thickness of the second powder layer.

Abstract: An apparatus for forming a three-dimensional article is provided, comprising means for providing a predetermined amount of powder, a powder distributor, means for directing an energy beam over a first powder layer causing it fuse in selected locations according to a model, a camera for capturing at least one image of a shape of at least one portion of the predetermined amount of powder that has yet to be initially distributed, the at least one image being captured prior to distribution of an entirety of all portions of the predetermined amount of powder over the surface, and means for comparing at least one value of at least one parameter in the image detected with a corresponding reference parameter value, wherein the at least one parameter is associated with the shape of the powder that has yet to be initially distributed.

Abstract: The invention concerns a method for producing three-dimensional objects (6) layer by layer using a powdery material (7) which can be solidified by irradiating it with a high-energy beam (4), said method comprising the steps of: applying a first layer of powdery material onto a working area (5); solidifying a part of said first layer by irradiating it with a high-energy beam; and applying a second layer (8) of powdery material onto the first, partly solidified layer. The invention is characterized in that the method comprises the step of: determining a rate at which the temperature of the second layer (8) increases after application onto the first layer. The invention also concerns an apparatus configured to operate according to the above method.

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

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: The present invention relates to a method 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 comprising the step of heating a first portion of a support surface while depositing a layer of powder material on a second portion of the support surface.

Abstract: Provided is a method for forming a three dimensional article comprising the steps of: providing at least one electron beam source emitting an electron beam for at least one of heating or fusing said powder material, where said electron beam source comprises a cathode, an anode, and a grid between said cathode and anode; controlling the electron beam source in at least two modes during said formation of said three dimensional article; applying a predetermined accelerator voltage between said cathode and said anode; applying a predetermined number of different grid voltages between said grid and said cathode for producing a corresponding predetermined number of electron beam currents; and at least one of creating or updating a look-up table or mathematical function during one of the at least two modes, wherein said look-up table or mathematical function defines a relationship between a desired electron beam current and an applied grid voltage.

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: A computer program product is configured for forming at least one three-dimensional article through successive fusion of parts of a powder bed, which parts correspond to successive cross sections of the three-dimensional article, by: providing a model of the at least one three-dimensional article; applying a first powder layer on a work table; directing a first energy beam from a first energy beam source over the work table causing the first powder layer to fuse in first selected locations according to corresponding models to form a first cross section of the three-dimensional article, where the first energy beam is fusing at least a first region of a first cross section with parallel scan lines in a first direction; varying a distance between two adjacent scan lines, which are used for fusing the powder layer, as a function of a mean length of the two adjacent scan lines.

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: 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: Various embodiments provide a method and apparatus for forming a three-dimensional article through successive fusion of parts of at least one layer of a powder bed provided on a work table in an additive manufacturing machine, which parts corresponds to successive cross sections of the three-dimensional article. The method comprises the steps of: applying a layer of predetermined thickness of powder particles on the work table, applying a coating on at least a portion of the powder particles, which coating is at least partially covering the powder particles, and fusing the powder particles on the work table with an electron beam.

Abstract: Provided is a method for forming a three dimensional article comprising the steps of: providing at least one electron beam source emitting an electron beam for at least one of heating or fusing said powder material, where said electron beam source comprises a cathode, an anode, and a grid between said cathode and anode; controlling the electron beam source in at least two modes during said formation of said three dimensional article; applying a predetermined accelerator voltage between said cathode and said anode; applying a predetermined number of different grid voltages between said grid and said cathode for producing a corresponding predetermined number of electron beam currents; and at least one of creating or updating a look-up table or mathematical function during one of the at least two modes, wherein said look-up table or mathematical function defines a relationship between a desired electron beam current and an applied grid voltage.

Abstract: A method for verifying a position of an energy beam spot, said method comprising the steps of: providing a calibrated energy beam having a first focus in a at least two positions at a work table, detecting said at least two positions of said energy beam spot on said work table created with said energy beam having said first focus, providing said calibrated energy beam having a second focus in said at least two positions at a work table, detecting said at least two positions of said energy beam spot on said work table created with said energy beam having said second focus, comparing said at least two positions created with said first and second focus, wherein said position of the energy beam is verified if said positions created with said first focus are deviating less than a predetermined distance from said positions created with said second focus.

Abstract: A method for verifying a size of an energy beam spot, said method comprising the steps of providing a first beam spot having a predetermined size and power at a first position on a work piece, varying a focus and/or astigmatism lens setting for said first beam spot until max intensity for the beam spot is detected, comparing the detected settings of said focus lens and/or astigmatism lens for said maximum intensity of the beam spot with stored settings of said focus lens and/or astigmatism lens for the beam spot with said predetermined size and power, repeating step a-c for different predetermined beam powers, repeating step a-d for different positions on said work piece, wherein said beam spot size is verified if each detected settings of said focus lens and/or astigmatism lens are deviating less than a predetermined value from corresponding stored settings of said focus lens and/or astigmatism lens.

Abstract: The present invention relates to a method for forming a three-dimensional article through successively depositing individual layers of powder material that are fused together so as to form the article, said method comprising the steps of: providing at least one electron beam source emitting an electron beam for heating and/or fusing said powder material. Controlling the electron beam source in a first mode when said formation of said three dimensional article is in a first process step. Controlling said electron beam in a second mode when said formation of said three dimensional article is in a second process step, wherein in said first mode an electron beam current from said electron beam source is controlled in a feed-forward mode and in said second mode said electron beam current is controlled in a feed-back mode.