Method and apparatus for additive manufacturing of a component, and component manufactured in accordance with the method

1 . A method for additive manufacturing of a component, comprising the steps of

providing at least one powder, and

producing a plurality of component layers of the component to be manufactured, wherein at least one powder fraction of the at least one powder is deposited to produce each component layer,

wherein each powder fraction is electrostatically charged in a developing station,

wherein a deposition unit is electrostatically charged at least in some regions,

wherein each electrostatically charged powder fraction is picked up by the deposition unit from the developing station and transferred to a deposition surface in a printing station by transferring the deposition unit with the powder fraction adhered thereto from the developing station to the printing station and depositing the powder fraction from the deposition unit onto the deposition surface,

wherein different powder fractions to be deposited to produce the component layers are electrostatically charged with different polarities, and

wherein the deposition unit is mechanically excited by an actuator of the deposition unit to deposit the powder fraction from the deposition unit onto the deposition surface.

2 . The method according to claim 1 , wherein the powder fractions to be deposited to produce successive component layers are electrostatically charged with alternating polarity.

3 . The method according to claim 1 , wherein a surface potential of the deposition surface is measured in order to determine the polarity of the powder fraction to be deposited next.

4 . The method according to claim 1 , wherein the pick-up and/or transfer of the electrostatically charged powder fraction by means of the deposition unit is contactless.

5 . The method according to claim 1 , wherein the powder fraction is preheated at the deposition unit.

6 . The method according to claim 5 , wherein the powder fraction is preheated at the deposition unit to a temperature T for which the following applies: TS−ΔT≤T<TS, wherein TS is a melting temperature of the powder fraction and ΔT is 30° C.

7 . The method according to claim 5 , wherein the powder fraction is preheated at the deposition unit to a temperature T for which the following applies: TR−δT<T, wherein TR is a recrystallization temperature of the powder fraction and δT is 20° C.

8 . The method according to claim 1 , wherein the deposition surface is preheated to a temperature T2, for which the following applies: TR<T2<TS, wherein TR is a recrystallization temperature and wherein TS is a melting temperature of the powder fractions to be deposited.

9 . The method according to claim 1 , wherein the deposition unit is vibrated at an excitation frequency of between 100 Hz and 20 KHz in order to transfer the powder fraction to the deposition surface.

10 . The method according to claim 9 , wherein the excitation frequency is in the range of one of the natural frequencies of the deposition unit.

11 . The method according to claim 1 , wherein the mechanical excitation takes place by a pulse sequence consisting of a strong pre-pulse and irregular subsequent pulses with a smaller amplitude.

12 . The method according to claim 1 , wherein the mechanical excitation takes place by a piezo actuator of the deposition unit.

13 . The method according to claim 1 , wherein an electric transfer field is generated between the deposition unit and a transfer structure for transferring the powder fraction to the deposition surface.

14 . The method according to claim 13 , wherein the deposition unit is mechanically excited by an actuator of the deposition unit in order to transfer the powder fraction to the deposition surface, after the electrical transfer field has been established completely.

15 . The method according to claim 1 , wherein at least two different powders are provided, wherein the at least two different powders are triboelectrically chargeable with different polarities.

16 . The method according to claim 1 , wherein the powder fraction picked up with the deposition unit has a layer thickness perpendicular to the deposition unit which is greater than twice the average particle diameter of the powder particles of the powder fraction.

17 . A component manufactured using a method according to claim 1 .

18 . An apparatus for additive manufacturing of a component, comprising:

at least one powder reservoir for storing at least one powder,

at least one powder charging unit for electrostatically charging powder fractions in a developing station, and

at least one deposition unit configured to be electrostatically charged, at least in some regions, for pick up and transfer of electrostatically charged powder fractions to a deposition surface in a printing station by transferring the deposition unit with the powder fraction adhered thereto from the developing station to the printing station and depositing the powder fraction from the deposition unit onto the deposition surface,

wherein the at least one powder charging unit is designed to electrostatically charge different powder fractions of the at least one powder to produce component layers with different polarity, and

wherein the deposition unit has an actuator for generating a mechanical excitation of the deposition unit for depositing the powder fraction from the deposition unit onto the deposition surface.

19 . The apparatus according to claim 18 , wherein the at least one deposition unit has a temperature control unit for preheating powder fractions at the deposition unit.

20 . The apparatus according to claim 18 , wherein the temperature control unit has fluid channels for a heat transfer fluid, which are formed in a base body of the deposition unit.

21 . The apparatus according to claim 18 , wherein the deposition unit has a conductive base body which is connected to a reversible deposition unit voltage source.

22 . The apparatus according to claim 18 , wherein the actuator is a piezo actuator.

23 . The apparatus according to claim 18 , comprising a transfer structure for generating an electric transfer field between the deposition unit and the transfer structure.