Powder-Bed-Based Additive Manufacture of a Workpiece
Various embodiments include methods for the powder-bed-based additive manufacturing of a workpiece comprising: manufacturing the workpiece layer by layer in a powder bed, including solidifying a respective uppermost layer of the powder bed using an energy beam. During the solidification of the respective uppermost layer of the powder bed, analyzing a geometry of previously solidified layers below the respective uppermost layer. The method may include reducing an average power over time introduced by the energy beam per unit of area of the powder bed with application of correction parameters if the heat dissipation into the previously solidified layers is reduced in dependence on the workpiece depth available below the energy beam.
1 . A method for the powder-bed-based additive manufacturing of a workpiece, the method comprising:
manufacturing the workpiece layer by layer in a powder bed, including solidifying a respective uppermost layer of the powder bed using an energy beam;
during the solidification of the respective uppermost layer of the powder bed, analyzing a geometry of previously solidified layers below the respective uppermost layer;
reducing an average power over time introduced by the energy beam per unit of area of the powder bed with application of correction parameters if the heat dissipation into the previously solidified layers is reduced in dependence on the workpiece depth available below the energy beam.
2 . The method as claimed in claim 1 , wherein the average power over time introduced per unit of area of the powder bed is reduced by applying one or more of the following correction parameters:
reducing a power of the energy beam;
increasing a feed rate of the energy beam on the powder bed; and
maintaining an irradiation pause between traveling along one exposure vector and traveling along an adjacent exposure vector, wherein the exposure vectors each describe parts of the path which the energy beam travels along to solidify the powder bed.
3 . The method as claimed in claim 1 , further comprising calculating the workpiece depth available below the energy beam using a data set describing the geometry of the workpiece.
4 . The method as claimed in claim 1 , wherein the workpiece depth available below the energy beam is only taken into consideration up to an established maximum depth.
5 . The method as claimed in claim 4 , wherein the maximum depth is at least 0.5 mm and at most 2 mm.
6 . The method as claimed in claim 4 , wherein the maximum depth corresponds to at least 10 and at most 40 layers.
7 . The method as claimed in claim 1 , further comprising describing the respective workpiece depth available below the energy beam for the uppermost layer as a contour function in dependence on a location for the area component to be solidified of the uppermost layer.
8 . The method as claimed in claim 4 , further comprising describing the respective workpiece depth available below the energy beam for the uppermost layer as a contour function in dependence on a location for the area component to be solidified of the uppermost layer;
wherein the contour function is scaled to 1;
wherein the value 1 is reached where the maximum depth is reached.
9 . The method as claimed in claim 7 , further comprising storing a correction function wherein the correction parameters for the average power over time introduced by the energy beam per unit of area of the powder bed based at least in part on the location, is associated with the contour function.
10 . The method as claimed in claim 9 , further comprising determining the correction parameters of the correction function based at least in part on the average value of the correction function or the minimum value of the correction function along an exposure vector;
wherein the exposure vector is a linear element of the feed of the energy beam.
11 . The method as claimed in claim 1 , further comprising accounting for, in the case of the determination of the correction parameters within a boundary zone of the contour, a distance from the boundary of the contour.
12 . A method as claimed in claim 7 , further comprising computing the respective workpiece depth available below an energy beam for layers to be processed of the powder bed as a contour function in dependence on the location for the area component of the layer to be solidified.
13 . A method as claimed in claim 9 , further comprising determining
the dimension for the reduction of the average power over time introduced by the energy beam per unit of area of the powder bed by producing a test specimen;
deriving the correction parameters from the dimension; and
storing the correction parameters with boundary conditions, which apply to the correction, for the manufacturing.
14 . A method as claimed in claim 9 , further comprising:
computing the dimension for the reduction of the average power over time introduced by the energy beam per unit of area of the powder bed using a simulation program;
deriving the correction parameters from the dimension; and
storing the correction parameters with boundary conditions, which apply to the correction, for the manufacturing.
15 . A computer program product for describing a respective workpiece depth available below an energy beam for an uppermost layer as a contour function in dependence on a location for an area component to be solidified of the uppermost layer, the product including a set of instructions stored in a non-transitory medium and when executed by a processor, causing the processor to:
compute the respective workpiece depth available below the energy beam to be used for additive manufacturing for the layer to be manufactured as a contour function in dependence on the location for the area component to be solidified of a respective layer of a powder bed;
receive a data set describing a geometry of a workpiece to be manufactured; and
provide as output for said contour function.
16 . (canceled)