METHOD AND APPARATUS FOR PRODUCING THREE-DIMENSIONAL OBJECTS

• US 20100270708A1
• Filed: 01/03/2008
• Published: 10/28/2010
• Est. Priority Date: 01/03/2008
• Status: Active Grant

• Current Assignee: Arcam Ab (Danaher Corporation)
• Original Assignee: Arcam Ab (Danaher Corporation)
• Inventors: Larsson, Morgan, Jonasson, Daniel, Ackelid, Ulf, Snis, Anders
• Granted Patent: US 8,992,816 B2
• Time in Patent Office: Days
• US Class Current: 264/401
• CPC Class Codes: B22F 10/20 Direct sintering or melting
• CPC Class Codes: B22F 10/36 of energy beam parameters
• CPC Class Codes: B22F 12/57 Metering means
• CPC Class Codes: B22F 12/90 Means for process control, e.g. cameras or sensors
• CPC Class Codes: B22F 2203/03 for feed-back
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B29C 64/268 using laser beams; using electron beams [EB]
• CPC Class Codes: B29C 64/393 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B29L 2009/00 Layered products
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

The invention concerns a method for producing three-dimensional objects (6) layer by layer using a powdery material which can be solidified by irradiating it with a beam (4) of charged particles, which method comprises the following steps: successive application of powder layers to a working area (5), and fusing together successive layers of said three-dimensional object (6) by successively irradiating the powdery layers with said beam (4). The invention is characterized in that it comprises the following steps: determining whether lifting of powdery material from the working area (5) occurs using a powder-lifting detection device (10, 10a, 10b, 10c, 10d, 10e) capable of generating a signal (S) upon detection of lifting of powdery material from the working area (5), and interrupting the irradiation of at least a part of the working area (5) where powder lifting occurs using the signal (S) generated by the powder-lifting detection device (10, 10a, 10b, 10c, 10d, 10e) for automatically trigging the interruption. The invention also concerns an apparatus (1) for producing three-dimensional objects (6) layer by layer using a powdery material which can be solidified by irradiating it with a beam (4) of charged particles, said apparatus (1) comprising means for successive application of powder layers to a work table, and a radiation gun (3) for delivering said beam (4) of charged particles, wherein the inventive apparatus (1) comprises a powder-lifting detection device (10, 10a, 10b, 10c, 10d, 10e) capable of generating a signal (S) upon detection of lifting of powdery material from the working area (5).

Claims

1-14. -14. (canceled)

15. A method for producing three-dimensional objects layer by layer using a powdery material which can be solidified by irradiating it with a beam of charged particles, which method comprises the following steps:

applying successive powder layers to a working area;

fusing together successive layers of said three-dimensional object by successively irradiating the powdery layers with said beam;

determining whether lifting of powdery material from the working area occurs using a powder-lifting detection device capable of generating a detection signal upon detection of lifting of powdery material from the working area; and

interrupting the irradiation of at least a part of the working area where powder lifting occurs using the detection signal generated by the powder-lifting detection device for automatically triggering the interruption.

16. The method according to claim 15, wherein:

the step of interrupting the irradiation of at least a part of the working area where powder lifting occurs is performed within a first time-period starting at a point of time when the detection signal is created; and

the first time-period is less than 5 seconds.

17. The method according to claim 16, wherein the first time-period is less than 500 ms.

18. The method according to claim 16, wherein the first time-period is less than 50 ms.

19. The method according to claim 15, wherein the step of interrupting the irradiation of at least a part of the working area where powder lifting occurs is performed by turning off the beam.

20. The method according to claim 15, wherein the step of interrupting the irradiation of at least a part of the working area where powder lifting occurs is performed by guiding the beam into another direction.

21. The method according to claim 20, wherein:

the beam is guided such as to irradiate other parts of the working area; and

the beam is operated with a reduced average beam power.

22. The method according to claim 15, further comprising the step of re-starting the irradiation of the part of the working area where powder lifting has occurred.

23. The method according to claim 22, wherein the re-starting of the irradiation is carried out automatically after a certain, second time-period from the step of interrupting the irradiation.

24. The method according to claim 22, further comprising the step of modifying certain operation parameters, such as heating parameters, before re-starting the irradiation.

25. An apparatus for producing three-dimensional objects layer by layer using a powdery material which can be solidified by irradiating it with a beam of charged particles, said apparatus comprising:

means for successive application of powder layers to a work table;

a radiation gun for delivering said beam of charged particles; and

a powder-lifting detection device capable of generating a detection signal upon detection of lifting of powdery material from the working area.

26. The apparatus according to claim 25, wherein the detection signal created by the powder-lifting detection device is used for automatically triggering interruption of the irradiation of at least a part of the working area where powder lifting occurs.

27. The apparatus according to claim 25, wherein the powder-lifting detection device comprises a detection unit that is capable of generating a primary signal that varies with varying amounts of powder particles present above or beside the working area.

28. The apparatus according to claim 26, wherein the powder-lifting detection device comprises a capacitor having two plates over which a voltage is applied.

29. The apparatus according to claim 28, wherein the apparatus is provided with a second powder-lifting detection device of the same type as defined in claim 27, wherein the second powder-lifting detection device is arranged to be insensitive to powder-lifting events, and wherein a difference signal from the two powder-lifting detection devices is used for generating the detection signal.