Arcam Ab

Johan Backlund

Tomas Lock

Martin Wildheim

Mattias Fager

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.

Method for controlling an energy beam

A standard reference plate is configured for insertion into an additive manufacturing apparatus for calibrating an electron beam of the additive manufacturing apparatus. The standard reference plate includes a lower plate and an upper plate being essentially in parallel and attached spaced apart from each other, the upper plate including a plurality of holes. A predetermined hollow pattern is provided inside the holes, and a spacing between the holes and the size of the holes and a distance between the upper plate and the lower plate and a position of an x-ray sensor of the additive manufacturing apparatus with respect to the standard reference plate are arranged so that x-rays emanating from the lower plate, when the electron beam is passing through a hollow part of the hollow pattern, will not pass directly from the lower plate through any one of the holes to the x-ray sensor.

X-ray calibration standard object

An electron beam source including a cathode, an anode, a means for deflecting an electron beam over a target surface and at least one vacuum pump, the electron beam source further including a contraction area arranged between the anode and the means for deflecting the electron beam where a hole in the contraction area is aligned with a hole in the anode with respect to the cathode, a first vacuum pump is arranged between the contraction area and the anode and a second vacuum pump is arranged above the anode, a gas inlet is provided between the contraction area and the means for deflecting the electron beam, wherein a first crossover of the electron beam is arranged between the cathode and the anode and a second crossover is arranged at or in close proximity to the contraction area.

Enhanced electron beam generation

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.

Apparatus for fusing a workpiece

Provided is an apparatus that includes a high energy beam configured to make a first weld at a first position on a workpiece; at least one deflection lens configured to deflect the high energy beam so as to cause the high energy beam to make a second weld at a second position; at least one focusing lens configured to focus the high energy beam; at least one astigmatism lens; and at least one controller. The controller is configured to shape the high energy beam so that the shape of the high energy beam on the workpiece is longer in a direction parallel to a deflection direction of the high energy beam than in a direction perpendicular to the deflection direction of the high energy beam. A length ratio is varying as a function of the power of the energy beam, while the width in the perpendicular direction is constant.

Apparatus, method, and computer program product for fusing a workpiece

An X-ray standard reference object for calibrating a scanning electron beam in an additive manufacturing apparatus by measuring X-ray signals generated by scanning the electron beam onto the reference object, the reference object comprises: a lower and an upper plate being essentially in parallel and attached spaced apart from each other, the upper plate comprises a plurality of holes, wherein a predetermined hollow pattern is provided inside the holes.

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Onsala, Sweden

Johan Backlund