Energy beam deflection speed verification

• US 9,310,188 B2
• Filed: 06/25/2015
• Issued: 04/12/2016
• Est. Priority Date: 08/20/2014
• Status: Active Grant

• Current Assignee: Arcam Ab (Danaher Corporation)
• Original Assignee: Arcam Ab (Danaher Corporation)
• Inventors: Snis, Anders
• Primary Examiner(s): Kim, Kiho
• Application Number:
  US14/750,752
• Publication Number:
  US 20160054347A1
• Time in Patent Office: 292 Days
• US Class Current: 1/1
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/31 Calibration of process steps or apparatus settings, e.g. before or during manufacturing
• CPC Class Codes: B22F 12/52 Hoppers
• CPC Class Codes: B22F 12/90 Means for process control, e.g. cameras or sensors
• CPC Class Codes: B23K 15/0013 Positioning or observing workpieces, e.g. with respect to the impact; Aligning, aiming or focusing electronbeams
• CPC Class Codes: B23K 15/0086 welding for purposes other than joining, e.g. built-up welding
• CPC Class Codes: B23K 15/02 Control circuits therefor
• CPC Class Codes: B23K 26/032 using optical means
• CPC Class Codes: B23K 26/04 Automatically aligning, aiming or focusing the laser beam, e.g. using the back-scattered light
• CPC Class Codes: B23K 26/046 Automatically focusing the laser beam
• CPC Class Codes: B23K 26/082 Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head
• CPC Class Codes: B23K 26/342 Build-up welding
• CPC Class Codes: B23K 26/70 Auxiliary operations or equipment
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: G01B 11/00 Measuring arrangements characterised by the use of optical techniques
• CPC Class Codes: G01B 11/14 for measuring distance or clearance between spaced objects or spaced apertures G01B11/26 takes precedence; rangefinders G01C3/00
• CPC Class Codes: G01B 15/00 Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons characterised by the use of optical techniques G01B9/00, G01B11/00
• CPC Class Codes: G01M 11/02 : Testing optical properties
• CPC Class Codes: G01P 21/00 : Testing or calibrating of apparatus or devices covered by the preceding groups
• CPC Class Codes: G01P 3/36 : Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light G01P3/68 takes precedence; gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams G01C19/64
• CPC Class Codes: H01J 37/244 : Detectors; Associated components or circuits therefor
• CPC Class Codes: Y02P 10/25 : Process efficiency

Abstract

A method for verifying a deflection speed of an energy beam spot, the method comprising the steps of: providing a predetermined pattern on a work table with the energy beam spot while deflecting the energy beam spot with a first deflection speed, detecting first positions of the energy beam spot on the work table created with the first deflection speed, providing the predetermined pattern on a work table with the energy beam spot while deflecting the energy beam spot with a second deflection speed, detecting second positions of the energy beam spot on the work table created with the second deflection speed, comparing the first and second positions, wherein the deflection speed is verified if each one of the first positions are deviating less than a predetermined distance from corresponding second positions.

Claims

1. A method for verifying a deflection speed of an energy beam spot, said method comprising the steps of:

generating, via an energy beam source, an energy beam spot;

generating, via one or more computer processors associated with a control unit, a predetermined pattern on a work table with said energy beam spot while deflecting said energy beam spot with a first deflection speed;

detecting, via said one or more computer processors associated with said control unit, first positions of said energy beam spot on said work table created with said first deflection speed;

generating, via said one or more computer processors associated with said control unit, said predetermined pattern on a work table with said energy beam spot while deflecting said energy beam spot with a second deflection speed;

detecting, via said one or more computer processors associated with said control unit, second positions of said energy beam spot on said work table created with said second deflection speed; and

comparing, via said one or more computer processors associated with said control unit, said first and second positions,

wherein;

said deflection speed is verified and building of a three-dimensional article layer-wise may proceed if each one of said first positions are deviating less than a predetermined distance from corresponding ones of said second positions; and

said building of said three-dimensional article layer-wise is prevented and a warning signal is generated and transmitted, via said one or more computer processors associated with said control unit, if any one of said first and second positions is deviating more than said predetermined distance.

2. The method according to claim 1, wherein said pattern is a continuous pattern.

3. The method according to claim 1, wherein said pattern is a discontinuous pattern.

4. The method according to claim 3, wherein said discontinuous pattern is created by switching on and off said energy beam.

5. The method according to claim 1, wherein said energy beam spot is at least one of an electron beam spot or a laser beam spot.

6. The method according to claim 1, wherein said positions are detected by at least one of an IR-camera, a CCD-camera, a digital camera, a CMOS camera, or a MR-camera.

7. The method according to claim 1, wherein said pattern is a one-dimensional pattern.

8. The method according to claim 1, wherein said pattern is a two-dimensional pattern.

9. The method according to claim 1, wherein said predetermined pattern provided on said worktable with said first and second deflection speeds is superimposed on the same work table.

10. The method according to claim 1, wherein said worktable is provided with a reference pattern.

11. The method according to claim 1, wherein said predetermined pattern is deflectionned in a forward direction and a reverse direction for each deflection speed.

12. The method according to claim 1, wherein said pattern is provided on said work table having a surface temperature above 500°

C.

13. The method according to claim 1, wherein said predetermined distance is less than 100 μ

m.

14. The method according to claim 1, wherein:

the method further comprises the step of receiving and storing, within one or more memory storage areas, a model of at least one three-dimensional article; and

when said deflection speed is verified, said building of said three-dimensional article layer-wise proceeds based upon said model.

15. An additive manufacturing apparatus for verifying a deflection speed of an energy beam spot, said apparatus comprising:

an energy beam source configured to generate an energy beam spot; and

a control unit configured for;

generating a predetermined pattern on a work table with said energy beam spot while deflecting said energy beam spot with a first deflection speed;

detecting first positions of said energy beam spot on said work table created with said first deflection speed;

generating said predetermined pattern on a work table with said energy beam spot while deflecting said energy beam spot with a second deflection speed;

detecting second positions of said energy beam spot on said work table created with said second deflection speed; and

comparing said first and second positions, wherein said deflection speed is verified if each one of said first positions are deviating less than a predetermined distance from corresponding ones of said second positions.

16. The additive manufacturing apparatus of claim 15, further comprising an image capture device configured to capture and compare said first and second positions.

17. The additive manufacturing apparatus of claim 15, further comprising at least one mirror positioned in a pathway between said first energy beam source and said work piece structure, said at least one mirror being configured for, via said control unit, directing said first energy beam.

18. The additive manufacturing apparatus of claim 17, wherein said at least one mirror is a tiltable or otherwise movable mirror.

19. A non-transitory program element configured and arranged when executed on a computer to implement a method for verifying a deflection speed of an energy beam spot, said method comprising the steps of:

generating a predetermined pattern on a work table with said energy beam spot while deflecting said energy beam spot with a first deflection speed;

detecting first positions of said energy beam spot on said work table created with said first deflection speed;

generating said predetermined pattern on a work table with said energy beam spot while deflecting said energy beam spot with a second deflection speed;

detecting second positions of said energy beam spot on said work table created with said second deflection speed; and

comparing said first and second positions,

wherein;

said deflection speed is verified and building of a three-dimensional article layer-wise may proceed if each one of said first positions are deviating less than a predetermined distance from corresponding ones of said second positions; and

said building of said three-dimensional article layer-wise is prevented and a warning signal is generated and transmitted, via said one or more computer processors associated with said control unit, if any one of said first and second positions is deviating more than said predetermined distance.

20. A non-transitory computer readable medium having stored thereon the program element according to claim 19.

21. A non-transitory computer program product comprising at least one non-transitory computer-readable storage medium having computer-readable program code portions embodied therein, the computer-readable program code portions comprising:

an executable portion configured for generating a predetermined pattern on a work table with said energy beam spot while deflecting said energy beam spot with a first deflection speed;

an executable portion configured for detecting first positions of said energy beam spot on said work table created with said first deflection speed;

an executable portion configured for generating said predetermined pattern on a work table with said energy beam spot while deflecting said energy beam spot with a second deflection speed;

an executable portion configured for detecting second positions of said energy beam spot on said work table created with said second deflection speed; and

an executable portion configured for comparing said first and second positions, wherein said deflection speed is verified and building of a three-dimensional article layer-wise may proceed if each one of said first positions are deviating less than a predetermined distance from corresponding ones of said second positions, and wherein said building of said three-dimensional article layer-wise is prevented and a warning signal is generated and transmitted, via said one or more computer processors associated with said control unit, if any one of said first and second positions is deviating more than said predetermined distance.