REAL-TIME VIBRATION MONITORING OF AN ADDITIVE MANUFACTURING PROCESS

• US 20170144250A1
• Filed: 11/19/2015
• Published: 05/25/2017
• Est. Priority Date: 11/19/2015
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Gold, Scott Alan, Kenney, Patrick Michael, Levine, Rachel Wyn
• Application Number:
  US14/946,278
• Publication Number:
  US 20170144250A1
• Time in Patent Office: Days
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/32 of the atmosphere, e.g. composition or pressure in a building chamber
• CPC Class Codes: B22F 10/36 of energy beam parameters
• CPC Class Codes: B22F 10/366 Scanning parameters, e.g. hatch distance or scanning strategy
• CPC Class Codes: B22F 10/38 to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures
• CPC Class Codes: B22F 10/73 of powder
• CPC Class Codes: B22F 10/85 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B22F 12/67 Blades
• CPC Class Codes: B22F 12/90 Means for process control, e.g. cameras or sensors
• CPC Class Codes: B22F 2202/01 Use of vibrations
• 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: B23K 26/03 Observing, e.g. monitoring, the workpiece
• CPC Class Codes: B23K 26/062 by direct control of the laser beam
• CPC Class Codes: B23K 26/0643 comprising mirrors
• CPC Class Codes: B23K 26/0648 comprising lenses
• CPC Class Codes: B23K 26/0652 comprising prisms
• CPC Class Codes: B23K 26/0869 Devices involving movement of the laser head in at least one axial direction
• CPC Class Codes: B23K 26/144 the fluid stream containing particles, e.g. powder
• CPC Class Codes: B23K 26/342 Build-up welding
• 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 64/393 : for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 50/00 : Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 50/02 : for controlling or regulating additive manufacturing processes
• CPC Class Codes: G01H 17/00 : Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves, not provided for in the preceding groups see provisionally also G01H1/00
• CPC Class Codes: G01N 2291/267 : Welds
• CPC Class Codes: G01N 29/043 : in the interior, e.g. by shear waves
• CPC Class Codes: G01N 29/0672 : by acoustic tomography medical tomography A61B8/13
• CPC Class Codes: G01N 29/221 : Arrangements for directing or focusing the acoustical waves electronic orientation or focusing G01N29/262; sound directing or focusing G10K11/26; mechanical steering of sound transducers or their beams G10K11/35
• CPC Class Codes: G01N 29/2418 : using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046
• CPC Class Codes: Y02P 10/25 : Process efficiency

Abstract

A method of monitoring an additive manufacturing process in which a layer of powdered material is deposited in a recoating process so as to define a build surface, and a directed energy source is used to create a weld pool in the build surface and selectively fuse the powdered material to form a workpiece. The method includes: measuring a vibration signal profile generated by the recoating process; and controlling at least one aspect of the additive manufacturing process in response to the measured vibration signal profile.

Claims

1. A method of monitoring an additive manufacturing process in which a layer of powdered material is deposited in a recoating process so as to define a build surface, and a directed energy source is used to selectively fuse the powdered material to form a workpiece, the method comprising:

measuring a vibration signal profile generated by the recoating process; and

controlling at least one aspect of the additive manufacturing process in response to the measured vibration signal profile.

2. The method of claim 1 further comprising comparing the measured vibration signal profile to a baseline vibration signal profile.

3. The method of claim 2 wherein the baseline signal profile is representative of a known good workpiece.

4. The method of claim 2 wherein the step of controlling includes taking a discrete action in response to the vibration signal profile deviating from the baseline profile.

5. The method of claim 4 wherein the discrete action is stopping the additive manufacturing process.

6. The method of claim 1 further comprising comparing the measured vibration signal profile to a baseline vibration signal profile and identifying a defect in workpiece based on the comparison.

7. The method of claim 6 further comprising repairing the defect, by using the directed energy source to melt material and permitting the material to flow into and fill the defect.

8. The method of claim 7 wherein the material is a previously fused portion of the workpiece.

9. The method of claim 1 wherein the step of controlling includes changing at least one process parameter of the additive manufacturing process.

10. The method of claim 9 wherein the controlled process parameter includes at least one of:

directed energy source power level, beam scan velocity, beam scan pattern, beam pulse length, and beam pulse frequency.

11. The method of claim 1 wherein the powdered material is deposited by a recoater arm moving over a worksurface, the vibration signal being generated by interaction of the recoater arm with the powdered material.

12. The method of claim 1 wherein the vibration signal profile is measured using a vibration sensor mounted to a machine used to perform the additive manufacturing process.

13. The method of claim 1 wherein:

The powdered material is spread across the build surface using a recoater arm; and

the vibration signal is generated by interaction of the recoater arm with the powdered material.

14. The method of claim 1 further comprising repeating in a cycle the steps of depositing and fusing to build up the workpiece in a layer-by layer fashion.

15. A method of monitoring an additive manufacturing process in which a layer of powdered material is deposited in a recoating process to define a build surface, and a directed energy source is used to selectively fuse the powdered material to form a workpiece, the method comprising:

measuring a vibration signal profile generated by a recoater during the recoating process; and

controlling at least one aspect of the additive manufacturing process in response to the measured vibration signal profile.