METHOD FOR ADDITIVELY MANUFACTURING AT LEAST ONE THREE-DIMENSIONAL OBJECT

1 . Method for additively manufacturing at least one three-dimensional object ( 2 ) by means of successive layerwise selective irradiation and consolidation of build material layers ( 3 ) applied in a build plane (BP) of an apparatus ( 1 ) for additively manufacturing three-dimensional objects ( 2 ) by means of at least one energy beam ( 5 ), wherein at least one build material layer ( 3 ) which is to be selectively irradiated and consolidated by means of the energy beam ( 5 ) comprises at least one build material layer section ( 11 ) having a curved shape with respect to at least one extension direction of the build material layer ( 3 ).

2 . Method according to claim 1 , wherein the or an at least one curved shape build material layer section ( 11 ) comprises at least one elevating or elevated portion ( 11 a ), particularly at least one portion which elevates and/or is elevated relative to a reference level or plane (RP), and/or at least one lowering or lowered portion ( 11 b ), particularly at least one lowering or lowered portion which lowers and/or is lowered relative to the reference level or plane (RP).

3 . Method according to claim 2 , wherein the elevated portions ( 11 a ) are elevated by an elevating value which is determined on basis of an elevation factor and the layer thickness (t) of the respective build material layer ( 3 ), particularly by multiplication of an elevation factor with the layer thickness (t) of the respective build material layer ( 3 ); and/or

the lowered portions ( 11 b ) are lowered by a lowering value which is determined on basis of a lowering factor and the layer thickness (t) of the respective build material layer ( 3 ), particularly by multiplication of a lowering factor with the layer thickness (t) of the respective build material layer ( 3 ).

4 . Method according to claim 1 , wherein a plurality of build material layers ( 11 ) are applied in such a manner that the respective build material layers ( 3 ) comprise at least one curved shape build material layer section ( 11 ), whereby the elevating or elevated portions ( 11 a ) and/or the lowering or lowered portions ( 11 b ) of respective curved shaped build material layer sections ( 11 ) of adjacently disposed build material layers ( 3 ) have the same slopes.

5 . Method according to claim 4 , wherein a plurality of build material layers ( 3 ) are applied in such a manner that the respective build material layers ( 3 ) comprise at least one curved shape build material layer section ( 11 ), whereby the elevating or elevated portions ( 11 a ) and/or the lowering or lowered portions ( 11 b ) of respective curved shaped build material layer sections ( 11 ) of adjacently disposed build material layers ( 3 ) have the same slopes such that a lower build material layer ( 3 ) engages with a vertically directly adjacently disposed upper build material layer ( 3 ).

6 . Method according to claim 4 , wherein a plurality of build material layers ( 3 ) are applied in such a manner that the respective build material layers ( 3 ) comprise at least one curved shape build material layer section ( 11 ), whereby the elevating or elevated portions ( 11 a ) and/or the lowering or lowered portions ( 11 b ) of respective curved shaped build material layer sections ( 11 ) of adjacently disposed build material layers ( 3 ) have the same slopes

such that top side portions of elevated portions ( 11 a ) of a lower build material layer ( 3 ) engage with bottom side portions of elevated portions ( 11 a ) of a directly adjacently applied upper build material layer ( 3 ) in vertical direction and/or

such that bottom side portions of lowered portions ( 11 b ) of an upper build material layer ( 3 ) engage with top side portions of lowered portions ( 11 b ) of a directly adjacently applied lower build material layer ( 3 ) in a vertical direction.

7 . Method according to claim 1 , wherein build material layer sections ( 11 ) having a curved shape are generated by concertedly changing the distance between a build material application element ( 13 ), which is configured to apply an amount of build material ( 4 ) in the build plane (BP) so as to generate a build material layer ( 3 ) which is to be selectively irradiated and consolidated, particularly the free end of the build material application element ( 13 ) being oriented towards the build plane (BP), and the build plane (BP), particularly the freely exposed top surface of the build plane (BP), during a build material application process.

8 . Method according to claim 1 , wherein the at least one build material layer ( 3 ) which is to be selectively irradiated and consolidated comprising at least one build material layer section ( 11 ) having a curved shape with respect to at least one extension direction of the build material layer ( 3 ) is generated by moving a build material application element ( 13 ), which is configured to apply an amount of build material ( 4 ) in the build plane (BP) so as to generate a build material layer ( 3 ) which is to be selectively irradiated and consolidated, in a combined motion in at least two different motion components across the build plane (BP), whereby a first motion component is or comprises a motion of the build material application element ( 13 ) in a direction parallel to the build plane (BP) and at least one further motion component is or comprises a motion of the build material application element ( 13 ) in a direction not parallel to the build plane (BP).

9 . Method according to claim 1 , wherein the at least one build material layer ( 3 ) which is to be selectively irradiated and consolidated comprising at least one build material layer section ( 11 ) having a curved shape with respect to at least one extension direction of the build material layer ( 3 ) is generated by moving a build material application element ( 13 ), which is configured to apply an amount of build material ( 4 ) in the build plane (BP) so as to generate a build material layer ( 3 ) which is to be selectively irradiated and consolidated, in a combined motion defined by at least two different motion components across the build plane (BP), whereby a first motion component is or comprises a motion of the build material application element ( 13 ) in a direction parallel to the build plane (BP) and at least one further motion component is or comprises a rotary motion, particularly a pivot motion, of the build material application ( 13 ) element around a rotary axis.

10 . Method according to claim 1 , wherein the at least one build material layer ( 3 ) which is to be selectively irradiated and consolidated comprising at least one build material layer section ( 119 having a curved shape with respect to at least one extension direction of the build material layer ( 3 ) is generated by a controlled, particularly oscillating, upward and downward motion of a moveably supported carrying element ( 10 ) carrying the build material layers ( 3 ) while a build material application element ( 13 ) moves across the build plane (BP).

11 . Method according to claim 1 , wherein at least one irradiation parameter, particularly the vertical focus position of the energy beam ( 5 ), for selectively irradiating respective build material layers ( 3 ) is determined on basis of the curved shaped build material layer section ( 11 ), particularly with regard to at least one irradiation and/or consolidation criterion.

12 . Method according to claim 1 , wherein the build data (BD) on basis of which the three-dimensional object ( 2 ) is additively manufactured contains the at least one build material layer ( 3 ) comprising the at least one build material layer section ( 11 ) having a curved shape.

13 . Control unit ( 6 ) for an apparatus ( 1 ) for additively manufacturing at least one three-dimensional object ( 2 ) by means of successive layerwise selective irradiation and consolidation of build material layers ( 3 ) applied in a build plane (BP) of a respective apparatus ( 1 ), the control unit ( 6 ) being configured to control the application of build material ( 4 ), particularly in accordance with the method according to claim 1 , in such a manner that at least one build material layer ( 3 ) which is to be selectively irradiated and consolidated is applied in such a manner that the build material layer ( 3 ) comprises at least one build material layer section ( 11 ) having a curved shape with respect to at least one extension direction of the build material layer ( 3 ).

14 . Apparatus ( 1 ) for additively manufacturing at least one three-dimensional object ( 2 ) by means of successive layerwise selective irradiation and consolidation of layers of build material ( 3 ) applied in the build plane (BP) of the apparatus ( 1 ) by means of at least one energy beam ( 5 ), comprising a control unit ( 6 ) according to claim 13 .