Method for operating a device for additive manufacturing of a three-dimensional object

Patent metadata

Field	Value
Publication number	US-12465976-B2
Application number	US-202217719427-A
Country	US
Kind code	B2
Filing date	Apr 13, 2022
Priority date	Oct 16, 2019
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

A method for operating a manufacturing device for additive manufacturing of a three-dimensional object includes irradiating a subregion of a build material within a building zone in which a beam of a beam source is directed onto the build material by a scanning unit. An amount of energy introduced is chosen such that the build material is solidified, so that a subregion of the three-dimensional object to be manufactured is formed. The method further includes controlling at least one irradiation parameter that characterizes the irradiation such that the irradiation parameter lies in a process window that changes location-dependently over an area of the building zone. The process window presets a relationship between a sensor signal detected by a sensor unit and permissible values for the irradiation parameter.

First claim

The invention claimed is:

1 . A method for operating a manufacturing device for additive manufacturing of a three-dimensional object, the method comprising:
irradiating a respective subregion of a plurality of subregions within a building zone in which a beam of a beam source is directed onto a build material by a scanning unit, wherein an amount of energy introduced is chosen such that the build material is solidified, so that a part of the three-dimensional object to be manufactured is formed in the subregion, and for each respective point in the respective subregion being irradiated by the beam, controlling at least one irradiation parameter that characterizes the irradiation such that the irradiation parameter lies in a process window that changes location-dependently over an area of the building zone, wherein a respective predefined process window is defined for each respective subregion of the plurality of subregions, the respective predefined process window presets a relationship between a sensor signal detected by a sensor unit and permissible values for the irradiation parameter, wherein the process window for the respective point corresponds to the respective predefined process window defined for the respective subregion or to two or more predefined process windows defined for subregions nearest to the respective point, and wherein the predefined process window for each respective subregion is defined for a respective preset fixed point in the respective subregion, and the method further comprises, for the respective point that deviates from the preset fixed point, determining the process window for the respective point by linear interpolation of the two or more predefined process windows defined for the subregions nearest to the respective point.

2 . The method as claimed in claim 1 , wherein the process window that changes location-dependently over the area of the building zone additionally changes in dependence on types of the subregion in the area of the building zone.

3 . The method as claimed in claim 2 , wherein the types of the subregion in the area of the building zone comprise at one of: contour, upskin, downskin, or inskin, with predetermined heat dissipation properties.

4 . The method as claimed in claim 3 , wherein the build material comprises a powdered build material, and the types of the subregion in the area of the building zone relate to a number of layers of the powdered build material that have already solidified under the subregion.

5 . The method as claimed in claim 3 , wherein the types of the subregion in the area of the building zone relate to a form of a contour.

6 . The method as claimed in claim 1 , wherein the process window presets at least one of: a traversing speed of the laser beam, a power of the laser beam, a pulse duration of the laser beam, a beam diameter in dependence on the detected sensor signal.

7 . The method as claimed in claim 1 , wherein, during the irradiation, a number of irradiation parameters that characterize the irradiation is chosen locally such that each of the number of irradiation parameters lie in a respective process window that changes location-dependently over the area of the building zone, and
wherein the respective process window presets a relationship between the sensor signal detected by the sensor unit and the permissible values for the respective irradiation parameter.

8 . The method as claimed in claim 1 , wherein the manufacturing device comprises a number of sensor units,
a number of irradiation parameters that characterize the irradiation is chosen locally such that the irradiation parameters lie in the process windows that change location—dependently over the area of the building zone, wherein the process windows preset a relationship between a number of sensor signals detected by the sensor units and permissible values for the irradiation parameters.

9 . The method as claimed in claim 1 , wherein the process window that changes location-dependently over the area of the building zone is formed while taking into account at least one machine parameter, wherein the machine parameter comprises at least one of:
an angle at which the beam impinges on the building zone, characteristics of inert gas flows, including a speed, a volume, a homogeneity, or a type of inert gas of the inert gas flows, a beam profile of the beam, including a projection of the beam onto a powder bed, or calibration measurements on calibration components at positions of the fixed points.

10 . The method as claimed in claim 1 , wherein the process window that changes location-dependently over the area of the building zone is additionally formed while taking into account at least one parameter of the build material.

11 . The method as claimed in claim 10 , wherein the at least one parameter of the build material comprises at least one of: a chemical composition, an average grain size, or a grain size distribution.

12 . The method as claimed in claim 1 , wherein the process window presets the irradiation parameter in dependence on at least one sensor signal that characterizes a melt pool, sensor signals that characterize the melt pool being at least the local temperature at the momentarily irradiated point, the local temperature at a measuring point preceding the irradiated point, the local temperature at a measuring point following the irradiated point, the cooling profile of an already irradiated point and/or the heating behavior of a point toward which the irradiated point moves.

13 . The method as claimed in claim 12 , wherein the at least one sensor signal that characterizes the melt pool comprises at least one of: a local temperature at a momentarily irradiated point, a local temperature at a measuring point preceding the irradiated point, a local temperature at a measuring point following the irradiated point, a cooling profile of an already irradiated point, or heating behavior of a point toward which the irradiated point moves.

14 . A method for creating a process window for additive manufacturing of three-dimensional objects, the method comprising:
building up a number of three-dimensional reference objects by applying layer by layer and selectively solidifying a build material within a building zone within each case at least one different irradiation parameter; detecting and recording one or more irradiation parameters in dependence on an irradiated position on the building zone; monitoring building operation by detecting sensor signals using one or more sensor units in dependence on the irradiated position on the building zone and recording of the sensor signals; checking the reference objects; dividing the building zone into a plurality of subregions; averaging the detected irradiation parameters and the sensor signals over each respective subregion; and for each respective subregion of the plurality of subregions, creating a respective process window by averaging the detected and recorded irradiation parameters and the sensor signals and also based on a result of the checking of the reference objects, the respective process window presetting a relationship between the sensor signals and permissible values for the irradiation parameter(s).

15 . The method as claimed in claim 14 , wherein the respective process window is for a fixed point with respect to a centroid of the respective subregion.

16 . The method as claimed in claim 15 , wherein, for the determination of the process window for each subregion, a number n of sensor signals are combined in an average-value vector of the length n, each entry

Assignees

• Trumpf Laser—und Systemtechnik GmbH
• Trumpf Laser & Systemtechnik Gmbh

Inventors

• Gronle Marc

Classifications

• B22F2203/11

  temperature, temperature profile · CPC title

• B22F2201/10

  Inert gases · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B22F12/90

  Means for process control, e.g. cameras or sensors · CPC title

• B22F12/41

  characterised by the type, e.g. laser or electron beam · CPC title