Energy dosing for additive manufacturing

Patent metadata

Field	Value
Publication number	US-2022080652-A1
Application number	US-202117535223-A
Country	US
Kind code	A1
Filing date	Nov 24, 2021
Priority date	Mar 29, 2017
Publication date	Mar 17, 2022
Grant date	—

Abstract

In one example, a processor readable medium having instructions thereon that when executed cause an additive manufacturing machine to vary operating characteristics of a fusing laser beam at multiple different voxel locations in a layer of build material according to an energy dosage to be applied at each voxel location in an object slice, including multiple different energy dosages for corresponding multiple different voxel locations in the slice.

First claim

1 . A processor readable medium having instructions thereon that when executed cause an additive manufacturing machine to irradiate fusible build material in a layer of fusible build material with a heating laser beam and a fusing laser beam overlapping the heating laser beam with the heating laser beam leading the fusing laser beam across the build material in both directions, the heating laser beam having a larger spot size and a lower intensity than the fusing laser beam.

2 . The processor readable medium of claim 1 , having instructions thereon that when executed cause the additive manufacturing machine to vary an operating characteristic of the fusing laser beam at multiple different voxel locations in the layer of build material according to an energy dosage to be applied at each voxel location in an object slice, including multiple different enemy dosages for corresponding multiple different voxel locations in the slice, where each energy dosage is represented by an energy value associated with each voxel of the object slice.

3 . The processor readable medium of claim 2 , having instructions thereon that when executed cause the additive manufacturing machine to associate an energy value with each voxel of the object slice.

4 . An additive manufacturing machine controller implementing the processor readable medium of claim 3 .

5 . An additive manufacturing process, comprising:
irradiating fusible build material in a first layer of fusible build material with overlapping laser beams; varying an intensity, spot size, and/or overlap of the laser beams at multiple different voxel locations in the first layer of build material according to an energy value associated with each voxel of an object, including multiple different values for corresponding multiple different voxels; detecting a characteristic of one or both of the laser beams and/or a temperature of fused build material in the first layer of build material; based on the detecting, changing the enemy values associated with some or all of the voxels; irradiating fusible build material in a second layer of fusible build material with the overlapping laser beams; varying an intensity, spot size, and/or overlap of the laser beams at multiple different voxel locations in the second layer of build material according to the changed enemy values; and repeating the irradiating, varying, detecting, changing, irradiating and varying for successive layers of build material.

6 . The process of claim 5 , comprising associating an energy value with each voxel of the object.

7 . The process of claim 6 , where each energy value represents an energy dosage describing a fusing enemy to be applied at the voxel location associated with the energy value.

8 . The process of claim 7 , where the energy value associated with the voxels in an overhang is lower than the energy value associated with the voxels not in the overhang.

9 . The process of claim 5 , where:
the irradiating includes scanning the laser beams over the build material; and the varying includes varying the speed at which the laser beams are scanned over the build material.

10 . The process of claim 5 , where the irradiating includes irradiating the build material with a fusing laser beam and with a heating laser beam having a larger spot size and a lower intensity than the fusing laser beam.

11 . The process of claim 10 , where the varying includes varying the intensity and the spot size of the fusing laser beam and/or the heating laser beam at multiple different voxel locations in the build material.

12 . The process of claim 10 , where the irradiating includes scanning the laser beams across the build material with the heating laser beam leading the fusing laser beam across the build material in both directions.

13 . An additive manufacturing machine, comprising:
a layering device to layer build material over a work area; a laser to generate a first laser beam and a second laser beam overlapping the first laser beam; a scanner to scan the first laser beam over the work area at a first scan speed and to scan the second laser beam over the work area at a second scan speed; optical elements between the laser and the scanner to adjust an intensity, spot size, and position of the laser beams; and a controller operatively connected to the laser, the scanner and the optical elements to: irradiate fusible build material in a first layer of fusible build material with the overlapping laser beams; vary an intensity, spot size, overlap, and/or scan speed of one or both of the laser beams at multiple different voxel locations in a first layer of build material according to an energy dosage associated with each voxel location of an object slice; detect a characteristic of one or both of the laser beams and/or a temperature of fused build material in the first layer of build material; based on the detecting, change the energy dosage associated with some or all of the voxels; irradiate fusible build material in a second layer of fusible build material with the overlapping laser beams; vary an intensity, spot size, and/or overlap of the laser beams at multiple different voxel locations in the second layer of build material according to the changed energy dosages; and repeat the irradiating, varying, detecting, changing, irradiating and varying for successive layers of build material.

14 . The machine of claim 13 , comprising an optical sensor to detect the intensity of one or both laser beams, the controller operatively connected to the optical sensor to change the energy dosages associated with some or all of the voxel locations based on the intensity detected by the optical sensor.

15 . The machine of claim 13 , comprising a thermal sensor to detect the temperature of fused and/or unfused build material in the work area, the controller operatively connected to the thermal sensor to change the energy dosages associated with some or all of the voxel locations based on the temperature detected by the thermal sensor.

16 . The machine of claim 13 , where:
the first laser beam comprises a heating laser beam; the second laser beam comprises a fusing laser beam; the heating laser beam has a larger spot size and a lower intensity than the fusing laser beam; and the controller is to irradiate fusible build material in each layer of build material with the heating laser beam leading the fusing laser beam across the build material in both directions.

Assignees

• Hewlett Packard Development Co

Inventors

• Addington Cary G
• Champion David A
• Shaarawi Mohammed S
• Mckinnell James
• Hammerstad Diane R

Classifications

• B29C64/268

  using laser beams; using electron beams [EB] · CPC title

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title

• B29C64/282

  of the same type, e.g. using different energy levels · CPC title

• B29C64/393

  for controlling or regulating additive manufacturing processes · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title