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: 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 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.

Abstract: A method 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, the method comprising the steps of: 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: The invention relates to a method for forming a three-dimensional article through successive fusion of locations of a powder bed. The method comprising: providing a model of said three-dimensional article; applying a powder layer on a work table; determining a maximum scan length of an energy beam; directing said energy beam from a first energy beam source over said work table with constant energy causing said first powder layer to fuse in first selected locations according to said model to form a first cross section of said three-dimensional article, wherein locations with a shorter scan length than said maximum scan length is provided with a time sink before and/or after said scan line so that the time period between each two adjacent scan lines is constant throughout the manufacture of said three-dimensional article.

Abstract: The invention concerns an apparatus (1) for producing three-dimensional objects (6) layer by layer using a powdery material which can be solidified by irradiating it with a beam (4) of charged particles, said apparatus (1) comprising means for successive application of powder layers to a work table, and a radiation gun (3) for delivering said beam (4) of charged particles, wherein the inventive apparatus (1) comprises a powder-lifting detection device (10, 10a, 10b, 10c, 10d, 10e) capable of generating a signal (S) upon detection of lifting of powdery material from the working area (5).

Abstract: A method for forming a three-dimensional article, said method comprising the steps of: providing a predetermined amount of powder for forming a first powder layer on a start plate, distributing said predetermined amount of powder with a powder distributor for forming said first powder layer, directing an energy beam over said start plate causing said first powder layer to fuse in selected locations according to a model to form a first cross section of said three-dimensional article. At least one image of the powder to be distributed is captured with a camera at least one time during said distribution of said powder on said start plate for forming said first powder layer and at least one value of at least one parameter in said image detected with said camera is compared with a reference parameter value.

Abstract: A device for detecting X-rays radiated out of a substrate surface, said device comprising at least one X-ray detector, a resolver grating and a modulator grating, said resolver grating with at least one opening facing towards said X-ray detector is arranged in front of said X-ray detector. Said modulator grating is provided between said resolver grating and said substrate at a predetermined distance from said resolver grating and said substrate, where said modulator grating having a plurality of openings in at least a first direction, wherein said x-rays from said surface is spatially modulated with said modulator grating and resolver grating.

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: A method for forming a three-dimensional article through successive fusion of parts of a powder bed, applying a first powder layer on a work table, directing a first energy beam from a first energy beam source over said work table causing said first powder layer to fuse in first selected locations according to a corresponding model to form a first cross section of said at least one three-dimensional article, where said first energy beam is fusing a first article with parallel scan lines in a first direction, fusing a second scan line in said first direction in said first layer in said first article within a predetermined time interval after fusing a first scan line in said first article, wherein at least one intermediate scan line is fused within said time interval at another predetermined position and where said first and second scan lines are adjacent to each other.

Abstract: A method for forming a three-dimensional article comprising applying a first powder layer on a work table; directing a first energy causing said first powder layer to fuse in first selected locations to form a first cross section where said first energy beam is fusing a first region with parallel scan lines in a first direction and a second region with parallel scan lines in a second direction; fusing at least one of the scan lines in said first region in said first direction immediately before fusing at least one of said scan lines in said second region in said second direction; applying a second powder layer and directing the energy beam causing said second powder layer to fuse in second selected locations where the energy beam is fusing said first region with parallel scan lines in a third direction and said second region in a fourth direction.