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: An apparatus for forming at least one three-dimensional article by fusing parts of a powder bed layer-wise. The apparatus comprising a powder distributor and an energy beam for fusing the powder layer. Said powder distributor comprises a first part being an elongated rod provided movable at a predetermined distance above the powder bed and with its central axis in parallel with a top surface of said work table and second part being a metal foil having at least a first and a second opposite edge portions. Said metal foil is provided between said elongated rod and said work table, said first and second opposite edge portions are attached to said elongated rod so that a distance between said first and second edge portions is smaller than the distance between said first and second edge portions of said metal foil when said metal foil is in a flat position.

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: 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 method 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 sources so as to form the article. Providing a model of said three-dimensional article; a vacuum chamber having at least a first and a second section, powder material that are fused together is provided in said first section, at least one electron beam source is provided in said second section, wherein said first and second sections are openly connected to each other. Directing an electron beam from said at least one electron beam source over said work table to fuse in first selected locations according to said model to form a first cross section of said three-dimensional article while supplying a gas to said second section of said vacuum chamber.

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: An apparatus for forming at least one three-dimensional article by fusing parts of a powder bed layer-wise. The apparatus comprising a powder distributor and an energy beam for fusing the powder layer. Said powder distributor comprises a first part being an elongated rod provided movable at a predetermined distance above the powder bed and with its central axis in parallel with a top surface of said work table and second part being a metal foil having at least a first and a second opposite edge portions. Said metal foil is provided between said elongated rod and said work table, said first and second opposite edge portions are attached to said elongated rod so that a distance between said first and second edge portions is smaller than the distance between said first and second edge portions of said metal foil when said metal foil is in a flat position.