Method and apparatus for additive manufacturing of a workpiece
A method of additively manufacturing a workpiece ( 22 ) from a powder material, comprises the steps of: (a) providing a device ( 15, 17 ) for receiving a powder bed ( 20 ) of the powdery material, in particular in a vacuum process chamber ( 11 ), and a beam generator ( 12 ) adapted to direct an energy beam ( 13 ) to laterally different locations of the powder bed ( 20 ); b) layer-by-layer application of the powdery material to the powder bed ( 20 ); c) creating the workpiece ( 22 ) in the powder bed ( 20 ) layer by layer by selectively bonding the powdery material to the energy beam ( 13 ); d) during the production of the workpiece ( 22 ), in addition to the workpiece ( 22 ), a cooling structure ( 30 ) is produced in the powder bed ( 20 ) by selective bonding of the powdery material to the energy beam ( 13 ), the cooling structure ( 30 ) being adapted to dissipate heat.
1 . A method of additively manufacturing a workpiece from a powder material, comprising the steps of:
a) providing
a device for receiving a powder bed of the powdery material in a vacuum process chamber, and
a beam generator adapted to direct an energy beam to laterally different locations of the powder bed;
b) layer-by-layer application of the powdery material to the powder bed;
c) layer-by-layer production of the workpiece in the powder bed by selective bonding of the powdery material by the energy beam;
wherein
d) during the production of the workpiece, in addition to the workpiece, cooling structures are produced in the powder bed by selective bonding of the powdery material by the energy beam, the cooling structures being arranged to dissipate heat, wherein the cooling structures are designed in such a way that
powdered material remains between the cooling structure and the device for receiving a powder bed as well as between the cooling structure and the workpiece,
the cooling structures extend to an uppermost final layer of the powder bed when production of the workpiece is completed,
the cooling structures have a cross-sectional area which is largest in the final layer,
the cooling structures are terminated by termination segments, and that
the final layer of the powder bed is formed entirely from the termination segments arranged in a grid pattern and separated by channels of unmelted powder, and
e) after step d) cooling at least one of the workpiece and the powder bed in the vacuum process chamber by dissipating heat via the cooling structures.
2 . The method according to claim 1 , wherein the cooling structure is predetermined depending on a desired heat distribution.
3 . The method according to claim 1 , wherein after step d), the workpiece is separated from the powder bed and the cooling structure, and the powder bed and the cooling structure are systematically disposed of in contrast to the workpiece.
4 . The method according to claim 1 , wherein the cooling structure is configured in multiple parts.
5 . The method according to claim 1 , wherein the cooling structure comprises one or more branches.
6 . The method according to claim 1 , wherein the cooling structure is actively cooled.
7 . The method according to claim 6 , wherein the cooling structure comprises at least one cavity through which a cooling fluid can be passed for active cooling.