Abstract: A method for non-destructive evaluation of a manufacturing process when forming a three-dimensional article through successive fusion of parts of a metal powder bed, which parts corresponds to successive cross sections of the three-dimensional article, the method comprising the steps of collecting an X-ray signal, created by the electron beam, from at least one position of the first and/or second metal powder layer and/or a melt pool of the first and/or second metal powder layer and/or a fused first and/or second powder layer by an X-ray detector, comparing the X-ray signal with a reference signal, alarming if the generated X-ray signal compared to the reference signal is indicating contamination material of larger amount than a predetermined value and/or a deviation in Atomic % of the powder material larger than a predetermined value.

Abstract: A method is provided for forming at least one three-dimensional article through successive fusion of parts of a powder bed. The method involves: providing a model of the at least one three dimensional article, dividing at least two cross sections in said model into a first inner area portion, a second inner area portion and a contour portion, applying a first material layer on a work table, directing at least one energy beam over the work table causing the first material layer to join in selected locations according to the model for forming a partial first cross section of the three dimensional article, applying a second material layer on said work table; and directing at least one energy beam over the work table causing the second material layer to join in selected locations and form a partial second cross section of said three dimensional article.

Abstract: A method is provided for production of at least one three-dimensional article by successively providing powder layers and fusing together of selected areas of the layers, which areas correspond to partial cross sections of the three-dimensional body. The method involves: applying a first powder layer on a work table, fusing the first powder layer in the selected areas, the selected areas being a full contour of the three dimensional article and a first portion of an inner area of the three-dimensional article, and fusing a second portion of the inner area of the three-dimensional article in the first powder layer completely when the first powder layer is covered with at least one second layer, the second portion being distinct relative to the first portion.

Abstract: A method for forming at least one three-dimensional article through successive fusion of parts of a powder bed, comprising the steps of: providing at least one model of said three-dimensional article, moving a support structure in z-direction at a predetermined speed while rotating said support structure at a predetermined speed, directing a first and second energy beam causing said powder layer to fuse in first and second selected locations according to said model, wherein a first cover area of said first energy beam on said powder layer is arranged at a predetermined minimum distance and non-overlapping from a second cover area of said second energy beam on said powder layer, a trajectory of said first cover area and a trajectory of said second cover area are at least one of overlapping each other, abutting each other or separated to each other when said support structure is rotated a full lap.

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: 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.

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