Selective laser solidification apparatus and method

Patent metadata

Field	Value
Publication number	US-11104121-B2
Application number	US-202016838095-A
Country	US
Kind code	B2
Filing date	Apr 2, 2020
Priority date	Mar 15, 2013
Publication date	Aug 31, 2021
Grant date	Aug 31, 2021

Abstract

A method of selecting a scanning sequence of a laser beam in a selective laser solidification process, in which one or more objects are formed layer-by-layer by repeatedly depositing a layer of powder on a powder bed and scanning the laser beam over the deposited powder to selectively solidify at least part of the powder layers, includes determining an order in which areas should be scanned by: projecting a debris fallout zone that would be created when solidifying each area based on a gas flow direction of a gas flow passed over the powder bed; determining whether one or more other areas to be solidified fall within the debris fallout zone; and selecting to solidify the one or more other areas that fall within the debris fallout zone before solidifying the area from which the debris fallout zone has been projected.

First claim

The invention claimed is:

1. A method of controlling an additive manufacturing process, in which a laser beam is used to selectively solidify powder of a powder bed to form, in the presence of gas-borne debris generated by the solidification of the powder, an object layer-by-layer, the method comprising:
determining a zone effected by the gas-borne debris; and
controlling the laser beam so as to prevent the laser beam from intersecting the zone.

2. The method according to claim 1 , further comprising generating a gas flow across the powder bed.

3. The method according to claim 2 , wherein boundaries of the zone are determined by projecting parallel lines in a gas flow direction across the powder bed.

4. The method according to claim 2 , wherein boundaries of the zone are determined by projecting diverging lines in a gas flow direction across the powder bed.

5. The method according claim 2 , further comprising using a model of the gas flow to determine the zone.

6. The method according to claim 2 , wherein the gas flow is a laminar gas flow.

7. The method according to claim 2 , further comprising using a gas inlet on one side of the powder bed and a gas outlet on another side of the powder bed to generate the gas flow.

8. The method according claim 1 , further comprising remelting debris that falls within the zone when solidifying powder of a successive layer.

9. A method of controlling an additive manufacturing process, in which a laser beam is used to selectively solidify powder of a powder bed to form, in the presence of gas-borne debris generated by the solidification of the powder, an object layer-by-layer, the method comprising:
determining a zone effected by the gas-borne debris; and
determining a scanning sequence of the laser beam so as to avoid the laser beam intersecting the zone.

10. The method according to claim 9 , wherein in the additive manufacturing process powder is solidified in the presence of a gas flow across the powder bed.

11. The method according to claim 10 , wherein boundaries of the zone are determined by projecting parallel lines in a gas flow direction across the powder bed.

12. The method according to claim 10 , wherein boundaries of the zone are determined by projecting diverging lines in a gas flow direction across the powder bed.

13. The method according to claim 10 , further comprising using a model of the gas flow to determine the zone.

14. A method of making an object, the method comprising repeatedly:
depositing powder to form a powder bed in a build chamber;
using a gas flow apparatus in fluid communication with the build chamber to provide a gas flow over the powder bed;
in the presence of the gas flow, directing a laser beam to selectively solidify the powder in a pattern corresponding to a cross-section of the object; and
controlling the laser beam so as to prevent the laser beam from intersecting a zone effected by gas-borne debris generated by the solidification of the powder,
wherein a scanning sequence of the laser beam is determined to avoid intersecting with the zone.

15. The method according to claim 14 , wherein boundaries of the zone are determined by projecting parallel lines in a gas flow direction across the powder bed.

16. The method according to claim 14 , wherein boundaries of the zone are determined by projecting diverging lines in a gas flow direction across the powder bed.

17. The method according claim 14 , further comprising using a model of the gas flow to determine the zone.

18. The method according to claim 14 , wherein the gas flow is a laminar gas flow.

19. The method according to claim 14 , further comprising using a gas inlet on one side of the powder bed and a gas outlet on another side of the powder bed to generate the gas flow.

20. The method according claim 14 , further comprising remelting debris that falls within the zone when solidifying powder of a successive layer.

Assignees

• Renishaw Plc

Inventors

• Ferrar Ben Ian

Classifications

• B22F10/322

  of the gas flow, e.g. rate or direction · CPC title

• B22F10/28

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

• B29C64/182 Primary

  in parallel batches · CPC title

• B22F10/80

  Data acquisition or data processing · CPC title

• B22F12/70

  Gas flow means · CPC title